ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • General Chemistry  (7,564)
  • GEOPHYSICS  (5,928)
  • Analytical Chemistry and Spectroscopy  (2,128)
  • Cell & Developmental Biology
  • 1970-1974  (13,756)
  • 1910-1914  (2,932)
Collection
Keywords
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974) 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 1-4 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Phosphorus-nitrogen rotation barriers have been determined by low temperature NMR methods in a variety of compounds of the type RP(X)NR2′. The observed activation parameters are concentration and solvent independent. Increasing the bulk of substituents on nitrogen increases the barrier. Phosphonamidous fluorides (X = F) have lower barriers than the corresponding chlorides (X = Cl). Increasing the bulk of substituents on phosphorus decreases the barrier.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 5-7 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: INDO-MO calculations have been performed on the ESR hyperfine coupling constants of the pyridinyl radical and the radical anions of pyrimidine, quinoline, isoquinoline, acridine and benzcinnoline. The nuclear spin coupling constants and the 14N nuclear quadrupole coupling constant of pyridine have also been calculated. In general, calculated values are in satisfactory agreement with the experimental data.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The configuration of isomeric 3,3-dimethyl-1-phenyl-1,3-dihydrobenzo[c]thiophene 2-oxides was assigned on the basis of selective benzene- and TFA-induced NMR shifts. The same method was employed for assigning the α-methyl resonances of these sulphoxides. Examination of NMR data for a variety of cyclic sulphoxides revealed that in CCl4 or CDCl3 solution, α-hydrogen cis to S—O often resonates at higher magnetic field, while α-methyl group cis to S—O characteristically resonates at lower field, than the same hydrogen or methyl group trans to S—O, respectively.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 16-19 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two simple formulae involving only one variable are presented for the simple and rapid estimation of the mean lifetime (τ) of exchange in uncoupled, paripartite AB systems. These formulae are shown to provide τ values comparable to those obtained from total line-shape analysis.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 11-15 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The NMR spectra of monochloro-, monobromo- and monofluoroacetone (CH3—CO—CH2X with X = Cl, Br, F) oriented in a nematic phase have been measured and the direct dipolar coupling constants determined. The barrier to internal rotation for the CH2F group has been studied for fluorine compound using various hypotheses. The best agreement with IR data has been obtained using the potential equation V(θ) = Σn Vn × (1 - cos nθ)/2 and a Boltzmann distribution of the CH2F group (V1 = 250 ± 50 cal.mol-1, V2 = 1650 ± 100 cal.mol-1, V3 = -1000 ± 100 cal.mol-1).
    Notes: Les spectres RMN des monochloro-, monobromo- et monofluoroacétone orientées dans une phase nématique ont été interprétés et les constantes de couplage dipolaire mesurées. La barrière s'opposant à la libre rotation du groupement CH2F a été étudiée pour le composé fluoré à l'aide de différentes hypothèses. En utilisant une répartition de Boltzmann pour peupler les différentes conformations du groupement CH2F, et une fonction potentielle de la forme V(θ) = Σn Vn(1 - cos n θ)/2, on obtient un bon accord avec les résultats d'infra-rouge pour V1 = 250 ± 50 cal.mol-1, V2 = 1650 ± 100 cal.mol-1, V3 = -1000 ± 100 cal.mol-1.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rotational barriers about the C—N bond of the N,N,N′,N′-tetramethyldiamides of phthalic, isophthalic and terephthalic acids have been determined by the iterative total line shape NMR method. Some evidence about the conformation of these compounds in solution has also been obtained by infrared and dipole moment studies.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 23-32 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: NMR studies on E and Z enolic phosphates with no substituent on carbon 1 provided evidence for the existence of planar and gauche conformations. When no bulky substituents are present in the cisoid position of the phosphates two planar and two gauche forms are possible. The most stable conformation is the planar form having the phosphate group trans to the double bond. With a bulky substituent in the cisoïd position of the phosphates the planar form with the group cis to the double bond could not be observed. A close agreement is obtained between the values of dihedral angles determined from observed coupling constants and those calculated with the CNDO/2 method. Changes observed in cisoïd and transoïd 4J(POCCH) coupling constants with temperature variation and the reversal of magnitude of these constants when a bulky substituent is on carbon 158 are explained.
    Notes: L'analyse RMN des phosphates d'énols E et Z non substitués sur le carbone 1, nous a permis de mettre en évidence l'existence de conformations planes et gauches. Dans le cas de phosphates ne comportant pas de groupement volumineux en position cisoïde par rapport au groupement phosphate, il est possible d'envisager deux formes planes et deux formes gauches. La conformation la plus stable est la forme plane où le groupement phosphate est en trans par rapport à la double liaison. Dans le cas de phosphates comportant un groupement volumineux en position cisoïde, la forme plane où le groupement est en cis par rapport à la double liaison n'a pu être mise en évidence. Un bon accord est obtenu entre les valeurs des angles dièdres des formes gauches déterminées à partir des constantes de couplage et calculées en utilisant la méthode CNDO/2. La variation des constantes 4J(POCCH) cisoïde et transoïde en fonction de la température, a pu être justifiée et permettra d'expliquer le renversement apparent de la valeur de ces constantes lorsque l'on place un substituant sur le carbone 158.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 33-34 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The NMR spectrum of 1-chloronaphthalene has been studied in the nematic phase of N-(p′-ethoxybenzylidene)-p-n-butylaniline. Ratios of interproton distances have been derived.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 43-44 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 13C magnetic resonance spectra of nine quaternary ammonium salts of the general formula R1C1(O)C2H=C3HNR34Cl (where R1, R4 = alkyl) were obtained and compared with those of the parent amino compounds. The chemical shift differences between these two classes of compounds are qualitatively accounted for by π-electron density changes. Steric effects and hyperconjugation of the alkyl substituents are also discussed.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The PMR spectra of six primary aziridinyl carbinols are studied over a temperature range of -30°C to +100°C. Nitrogen configuration is determined. When the inversion process is effective, kinetic parameters are evaluated. Rotational isomerism about the ‘ring—CH2OH’ bond is studied from vicinal coupling constants associated with the two diastereotopic protons on the —CH2OH group. From the J(HOCH) coupling constant (in CCL4) rotamer populations of the hydroxyl group are determined in some cases and the overall conformational distribution can be established.
    Notes: Six alcools primaires aziridiniques diversement substitués sont étudiés en résonance magnétique nucléaire, à différentes températures. La configuration à l'azote est établie; lorsque l'inversion est effectivement observée, les paramètres cinétiques associés au phénomène sont déterminés. L'isomérie de rotation autour de la liaison cycle-carbone porteur de l'hydroxyle est étudiée à partir des deux constantes de couplage vicinales correspondant aux deux protons diastéréotopiques du groupement hydroxyméthyle. La rotation de l'hydroxyle est également abordée au moyen du couplage J(HOCH) déterminé dans CCl4 pour certains termes. Une description globale des conformations peut être alors établie.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 45-47 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 13C chemical shifts and 1J(14N—13C) coupling constants as well as stretching frequencies of the isocyano group are reported for some representative aliphatic, unsaturated and aromatic isocyanides and for two copper(I) isocyanide complexes. The results are discussed in terms of the inductive and mesomeric substituent effects on the polarisation and charge density of the C—N≡C bonds. The marked solvent effect on the chemical shifts of the isocyano carbon hampers comparison of our data with previously reported data. The hydrogen bonding shift of this carbon in water or methanol is much smaller than previous data suggest.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 53-54 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The chemical shifts of the N-methyl group in a series of 2-, 3- and 4-substituted N-methylpyridinium salts have been measured in DMSO solution. The shift is primarily affected by resonance interaction between the substituent and aza group, and the results suggest that the resonance effect from a 2-substituent is at least as great as from the corresponding 4-substituent.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A study of the 1H and 13C NMR spectra of the N-formyl-2,2,5-trimethyl-4-carboxythiazolidines and the N-formyl-4-carboxy-5-methylthiazolidines derived from the two diastereoisomeric 2-amino-3-mercapto-DL-butyric acids, permits unambiguous assignment of the erythro and threo configuration of these amino acids. The spectra of the N-formylthiazolidines, recorded in DMSO-d6 solution, reveal the presence of two conformational isomers with a low rate of interconversion. The geometry around the carbon-nitrogen bond and correlated conformations of the 5-membered ring in both forms are discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 60-61 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: From the single and double resonance 1H NMR spectra of triphenylphosphine, magnitudes and relative signs of the proton-proton and proton-phosphorus spin coupling constants were calculated. The values of these parameters were found to be nearly equal to those of the respective 1H - 1H couplings in benzene. Results show that inter-ring proton-proton couplings are negligibly small.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The PMR spectrum of 2-bromo-4,6-dinitrophenyl 2′-naphthyl ether (1) is consistent with the preferential adoption of a twist conformation (1a) in which the 6-nitro group and the 1′-hydrogen are located endo to the ether link. This preference is explained by the formation of an intramolecular π complex between the 6-nitro group and the C1′—C2′ bond, which is stronger than that formed with the C2′—C3′ bond, in accord with their bond orders. This study adduces further evidence in favor of: (a) the adoption of twist conformations by these and related ethers, (b) the importance of intramolecular π complex formation as a conformational influence, (c) the formation of complexes in such cases is with specific portions of, and not the complete, π cloud and (d) indicates that similar effects may be discerned in analogous ethers related to the thyroid hormones.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 64-64 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An earlier short communication on this topic reports some incorrect 11B—13C coupling parameters. The correct data are given together with some 10B coupling and isomer shift data.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 62-63 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The natural abundance C-13 NMR spectra of 1,1-diphenylethylene and α-methylstyrene dimer dianions have been obtained using the proton noise decoupling technique. The extra negative charge distributions in the carbanions have been discussed and compared with those obtained from the proton chemical shifts. The chemical shifts of the two ortho carbons in a phenyl ring are equivalent to each other for the former carbanion but not for the latter.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. A7 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974) 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 65-65 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 66-72 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Long range 5J(FH) and 6J(FH) couplings were observed for silanes of the type (C6F5)nSiR4-n (n = 1, 2, 3; R = alkyl, aryl) and disilanes C6F5[Si(CH3)2]2R (R = CH3, C6F5). A characteristic increase in line width for 19F-NMR spectra of (C6F5)nSiR4-n(n ≧ 2) is thought to be due to spin systems of the type ([AC]2B)n or ([AX]2M)n with intra-annular couplings between ortho-fluorine atoms of neighbouring ring systems.
    Notes: Longrange-Kopplungen des Typs 5J(FH) und 6J(FH) werden bei Silanen des Typs (C6F5)nSiR4-n (n = 1, 2, 3; R = Alkyl, Aryl) sowie den Disilanen C6F5[Si(CH3)2]2R (R = CH3, C6F5) beobachtet. Eine typische Linienverbreiterung der Fluor-resonanzspektren von (C6F5)nSiR4-n (n ≧ 2) wird auf Spinsysteme des Typs ([AC]2B)n bzw. ([AX]2M)n mit interanularen Kopplungen der ortho-Fluor-atome benachbarter Ringe zurückgeführt.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 85-86 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 13CH satellite NMR spectra have been employed in the analysis of an unknown reaction product. Observation of the deceptively simple 1H NMR spectrum did not, in this instance, yield sufficient information for identification of the compound. However, with the aid of the satellite parameters the reaction site became clearly defined and the structure was assigned as α-(chlorovinyl)-dichlorophosphine. These unique spectral parameters are discussed and compared to those of similar ethylenic species.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 78-84 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The 13C-chemical shifts of 6 substituted oxepins have been measured and assigned. The average signals of the oxepins 1a (unsubstituted) and 1d (2,5-dimethyloxepin), which are in equilibrium with the corresponding benzeneoxides, were assigned by temperature dependent signal shifts and line broadening. Finally, the oxepin system is compared with the cycloheptatriene system.
    Notes: Die 13C-chemischen Verschiebungen von 6 substituierten Oxepinen wurden vermessen und zugeordnet. Für die mit den entsprechenden valenztautomeren Benzoloxiden im Gleichgewicht stehenden Oxepine 1a (unsubstituiert) und 1d (2,5-Dimethyl-oxepin) wurden die Mittelwertsignale durch ihre Verschiebung bzw. Verbreiterung in Abhängigkeit von der Temperatur bestimmt. Schließlich werden Vergleiche zum Cycloheptatriensystem gezogen.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The NMR spectra of syn-anti oxime isomers have been studied. A relationship between the magnitude of the α- protons' chemical shifts and the dihedral angle formed by the α C—H bond and the =N—OH plane has been discussed. A correlation curve Δδ = f (dihedral angle) has been determined from sterically rigid models and used to evaluate the conformation of cyclic molecules, the geometry of which has not yet been studied. The geometry of the oxime is similar to the ketone, with the exception of sterically crowded models.
    Notes: L'étude RMN des systèmes syn-anti d'oximes cyclaniques figés nous a permis de mettre en évidence une relation entre le déplacement chimique d'un proton voisin du groupement hydroximino et l'angle dièdre constitué par la liaison C—H du carbone en α de la fonction et le plan constitué par le groupe N—OH. La correlation Δδ = f (angle dièdre), établie par l'étude de modèles conformationnellement connus permet alors d'évaluer les angles dièdres de molécules cycliques dont l'étude géométrique n'avait pas été faite. La géométrie de l'oxime reste identique à celle de la cétone, sauf, toutefois, dans le cas de modèles stériquement encombrés.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 87-88 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The spectral parameters of the title compounds were redetermined to resolve discrepancies between data reported in the literature.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 99-102 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chemical shifts are reported for the acetyl protons in a series of para-substituted acetophenones in a number of solvents, and substituent effects evaluated statistically by means of the Swain-Lupton multiple correlation analysis. A basic set of substituents was built up by careful choice of substituted derivatives, and it was shown that this facilitated the possibility of valid comparisons of substituent effects between differing systems. Strong emphasis was placed on the idea of individuality of substituents and solvents.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The structural, solvent and temperature effects on the PMR spectra of several alkyl alkanesulfinates and arenesulfinates are discussed. A low order intrinsic nonequivalence was observed in substituents alpha to the sulfinate sulfur atom, the nonequivalence being significantly less than in sulfoxides, and solvent and temperature dependent. Nonequivalence of diastereotopic substituents on the ester oxygen exceeded nonequivalence in similar sulfoxides and is largely insensitive to temperatures from 25° to 120°C. Benzene complexes with sulfinates greatly enhancing the proton nonequivalence of alpha substituents apparently by causing a further shielding of the already more shielded nonequivalent protons.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Temperature dependence of cis- and trans-vicinal spin-spin coupling constants of substituted cyclic 5-membered compounds is discussed. The temperature dependence of trans-vicinal coupling constants is shown to be essentially stronger than that of cis-vicinal coupling constants if the energies of the conformers corresponding to potential energy curve minima are different. The temperature dependence of 33 vicinal spin-spin coupling constants has been studied for di- and trisubstituted thiophanes with a known configuration of substituents. Experimentally determined changes of trans-vicinal coupling constants with temperature are markedly larger than those for cis-vicinal coupling constants, whose values, in most cases, are practically temperature independent. Differences in the temperature dependence of cis and trans-vicinal spin-spin coupling constants can be applied for the determination of the configuration of substituents in saturated 5-membered rings.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 103-105 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The chemical shifts of the CH and OCH3 protons are obtained for the following compounds (meso and racemic forms) in several solvents: in (CD3)2CO; (RCHCO2H)2 (R = Cl, Br, C6H5S, CH3COS), (C6H5CHCO2H)2S and (C6H5CHCO2H)2S2; in (CD3)2CO, CDCl3, CCl4, C6D6, CS2; (RCHCO2CH3)2 (R = Cl, Br, C6H5, C6H5S, CH3COS), (C6H5CHCO2CH3)2S and (C6H5CHCO2CH3)2S2. It was shown that the chemical shift of a proton in the meso form could be than in the racemic form. The difference between them cannot be used for an assignment of relative configurations of the meso and racemic forms. The difference between the NMR spectra of a meso and a racemic form is often sufficient for their determination in a mixture.
    Notes: Die chemischen Verschiebungen der CH- und (OCH3)-Protonen der folgenden in meso- und racem-Formen vorkommenden Verbindungen wurden in verschiedenen Lösungsmitteln bestimmt: in (CD3)2CO; (RCHCO2H)2 (R = Cl, Br, C6H5S, CH3COS), (C6H5CHCO2H)2S und (C6H5CHCO2H)2S2; in (CD3)2CO, CDCl3, CCl4, C6D6, CS2; (RCHCO2CH3)2 (R = Cl, Br, C6H5, C6H5S, CH3COS), (C6H5CHCO2CH3)2S und (C6H5CHCO2CH3)2S2. Es wurde gezeigt, dass die chemische Verschiebung eines Protons in der meso-Form derjenigen in der racem-Form sein kann und dass die Differenzen zwischen ihnen nicht zu einer relativen Konfigurationsbestimmung verwendet werden können. Der Unterschied in den NMR-Spektren einer meso- und einer racem-Form ist in den meisten Fällen hinreichend gross, um eine Bestimmung der beiden Formen in einem Gemisch derselben zu ermöglichen.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 115-120 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The NMR spectra of a series of heterocyclic compounds analogous to anthracene have been investigated at 220 and 60 MHz. Correlations have been made with molecular geometry and parameters calculated from semi-empirical MO theory. For planar molecules, the chemical shift of the proton ortho to the heteroatom is linear with respect to the electron density on the heteroatom, but otherwise chemical shifts are independent of electron density. Planarity of the molecules is also a factor in some of the coupling constants.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 121-125 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Proton magnetic resonance spectra of 2,4-dimethyl-2,4-pentadiene have been examined for a number of solution conditions and (for a CF2Cl2 solution) over a range of temperatures. Coupling constants for the ethylenic protons were obtained from double resonance (methyl decoupled) spectra. Further double resonance experiments established the sign of 4Jc. It is found that 4Jc = -1·20 Hz and [4Jt] = 0·18 Hz. It is concluded that the compound exists in a single nonplanar conformation with an average dihedral angle (from the s-cis form) φ = 50° ± 15°. Some long range coupling constants involving the methyl group were found to be appreciable in spite of the lack of planarity of the diene chain.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 100 MHz spectrum of 1,3-oxathiane-3-oxide is reported. Parameters obtained from first order analyses are interpreted in terms of an absence of a conformational preference of the S=O bond at 38°C, but an axial preference at low temperatures. The behaviour contrasts with that found previously in the 1,3-dithiane-1-oxide series.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 129-132 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The molecule N,N-dimethylacetoacetamide, which is subject to a keto-enol equilibrium process in solution, also exhibits hindered rotation about the amido N—C bond. The hindered rotation rates have been studied by lineshape fit methods of the nuclear magnetic resonance spectra. In spite of some overlap of the keto and enol N-methyl proton signals, the simultaneous measurement of the two distinct energy barriers in the two forms is possible as well as a determination of the keto-enol equilibrium. The differences in free energy of activation between keto and enol forms for the rotation barrier can be related to the conjugation energy of the N—C π system with the enolic hydrogen bonded ring. Appeal to the model compound acetylacetone reveals a consistent set of energies for the keto and enol forms in the ground and transition states for internal rotation. The opportunity has been taken to reexamine and compare the keto-enol system ethylacetoacetate. Long range, solvent, concentration and temperature sensitive scalar couplings 4J(HH) between the enolic -OH and the adjacent methyl group in acetoacetic ester have not hitherto been reported.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: This work is concerned with the relationship between chemical shifts (δ) of protons and their charge densities (q). It can be shown that the relation δH = a + bqH + cqC (qC = charge density at the corresponding C-atom) fits best for a prediction of δ-values from calculated charge densities. The smallest standard error for the prediction of δ-values is obtained if the charge densities are calculated by the CNDO- or INDO-method.
    Notes: Es ist gezeigt worden, daß von den in dieser Arbeit untersuchten Beziehungen zwischen den chemischen Verschiebungen δ von Protonen und deren Ladungsdichten q die Beziehung δH = a + bqH + cqC (qC ist die Ladungsdichte des mit dem Proton in Bindung stehenden C-Atoms) für eine Voraussage der δ-Werte aus gerechneten Ladungsdichtewerten am geeignetsten ist. Der Standardfehler der Voraussage der δ-Werte wird dabei am kleinsten, wenn die in die Beziehung einzusetzenden Ladungsdichtewerte nach der CNDO- oder INDO-Methode berechnet werden.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 155-160 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The temperature dependence of the carbon-13 NMR signals in three completely substituted 1,3,5-trineopentylbenzenes has been studied by the Fourier transform technique. The assignment of all peaks was based on studies of 1,3,5-trineopentylbenzene and some of its mono- and disubstituted derivatives. Nearly all carbon signals showed a splitting into several peaks at low temperature, which gave information about the existing rotamers in the completely substituted compounds. Spectra for one compound were studied in a narrow temperature interval in order to test the reliability of rate constants obtained from 13C FT spectra. Good agreement was found between previously reported values obtained from 1H NMR and those obtained in this investigation.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 178-180 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 13C chemical shifts are reported for adamantane, nine 1-substituted adamantanes and nine 2-substituted adamantanes. The substituents are F, Cl, Br, I, NH2, OH, CH2, CN and CO2H. The assignments and results are discussed in terms of chemical shift patterns.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Temperature dependent proton magnetic resonance spectra of dichloro- and dimethyltin(IV) bis(N,N-di-isopropyl-dithiocarbamate) (1 and 2, respectively), dimethylchlorotin(IV) N,N-di-isopropyldithiocarbamate (3), dimethyltin(IV) bis(N-isopropyldithiocarbamate) (4), S-methyl-N,N-di-isopropyldithiocarbamate (5) and S-methyl-N-isopropyldithiocarbamate (6) were measured in halogenated hydrocarbons or CS2. The internal rotation around the isopropyl-nitrogen bond of 1, 2, 3 and 5 is restricted below -30°C, and that of 4 and 6 below -70°C; 1, 2 and 3 exist as only one conformer in dichloromethane, while 5 exists as two rotational isomers with respect to the isopropyl-nitrogen bond with a mole ratio of about 2·7:1·0 in CS2 below -30°C. At this temperature, 6 exists as two stereoisomers in CS2 with a mole ratio of about 1·2:1·0, although there is no stereoisomer in 4. From these results, possible conformations of the compounds at low temperature are proposed and the assignments of each proton signal are described.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbon-13 NMR spectra of pyridine have been observed by using the slow scan technique in the absorption mode. The long range coupling constants between carbon-13 and protons have been obtained and assigned by the isotope substitution method.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 190-192 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The methyl 1H NMR shifts for series of para-substituted N,N-dimethylanilines as their conjugate acids in trifluoroacetic acid, and series of para-substituted N,N,N-trimethylphenyl-ammonium iodides in acetonitrile and in deuterium oxide, and the methylene shifts for series of para-substituted N,N-diethylanilines as their conjugate acids in deuteriosulfuric acid, are shown to be linearly related to the Hammett σp+ parameter. It is proposed that this dependence reflects a response of the chemical shift of the proton of the probe moiety to the electron density at the point of attachment of the probe to the aromatic ring and that this response is determined by the electric field effect of the charge at the point of attachment. Literature data are cited to indicate that Hammett σp+-1H NMR shift relationships may be general for probe moieties lacking a through-resonance mechanism for interaction between the probe and the aromatic ring.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. A11 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974) 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 269-271 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Electron paramagnetic resonance studies were carried out on the radical anion of 4-deuterobenzocyclobutadienoquinone. The hyperfine coupling constants which had been assigned previously were found to be in error. The effects of the strained 4-membered ring on the spin density distribution are discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 276-278 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: [B(C6H5)4]⊖ is an efficient NMR shift reagent for aminosulphonium cations. An example is presented where diastereotopic protons fail to show anisochronism under ordinary conditions (chloride in CDCl3). The nonequivalence is revealed by a solvent effect, but this is insufficient in magnitude to make the geminal coupling constant and the true signal positions available. [B(C6H5)4]⊖, however, creates almost a first order spectrum from which all parameters can easily be obtained. The data are useful to locate very weak signals in the chloride spectrum and to evaluate the amount of anisochronism in the chloride. Salt mixtures help to recognise hidden signals.
    Notes: [B(C6H5)4]⊖ ist ein leistungsfähiges NMR-Verschiebungsreagens für Aminosulfonium-Kationen. In einem Beispiel zeigen diastereotope Protonen unter normalen Meßbedingungen (Chlorid in CDCl3) keine Anisochronie. Diese wird durch einen Solvenseffekt sichtbar, jedoch nur in einem Maße, das die geminale Kopplungskonstante und die wahren Signallagen noch nicht zu ermitteln gestattet. [B(C6H5)4]⊖ erzeugt jedoch annähernd ein Spektrum erster Ordnung, dem alle Parameter glatt entnommen werden können. Die Daten helfen im Chlorid-Spektrum sehr schwache Signale aufzuspüren und das Ausmaß der Anisochronie festzustellen. Salzmischungen legen verdeckte Signale frei.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 284-288 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The barrier to the internal rotation of the dimethylamino group in thioamides of structure R—CS—N(CH3)2, R being (CH3)2,N—CS—, CH3O2C— or N≡C—, is studied by proton magnetic resonance, using the lineshape analysis method of Nakagawa. In the solvents o-dichlorobenzene, naphthalene and nitrobenzene all ΔG≠ values are in the range of 23 to 24 kcal/mol. In these solvents the Ea and ΔS≠ values of each product are linearly related to the dielectric constants.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 300 MHz 1H NMR spectrum of 4-vinylbutyrolactone has been recorded and analysed. The results showed that the compound is a mixture of two rapidly interconverting envelope forms in which (C-3) is the flap atom. The vinyl group favours the pseudo-equatorial orientation by 1·9 ± 0.3 kJ mol-1, as shown by the dependence of the vicinal coupling constants on temperature.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. A9 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 322-323 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The complex between triethylaluminium and diethylether has been studied by 1H NMR; separate signals have been observed for free and bonded triethylaluminium. From the area ratios, a 1:1 stoichiometry is demonstrated. At higher ether concentrations, chemical shift measurements prove that other complexes do not appear.
    Notes: La complexation entre le triéthylaluminium et l'éther diéthylique a été étudiée par résonance magnétique du proton. On a pu observer des signaux distincts pour le triéthylaluminium libre et le triéthylaluminium lié. Une stoechiométrie 1:1 est démontrée grâce aux rapports des aires de ces signaux. A plus haute concentration d'éther, des mesures de déplacements chimiques prouvent qu'il n'apparaît pas d'autres complexes.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 497-498 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The four isomeric 3-dimethylamino-trans-2-decalols-1,1,4,4-d4 have been synthesised. Examination of PMR spectra of these compounds allows us to confirm the ‘flattened-chair’ conformation for the cis N(CH3)2a OHe isomer, whereas the remaining three conserve the double chair conformation. The same type of flattening is also observed in the case of the diaxial quaternary ammonium salt and is even more marked in the cis N(CH3)3a OHe isomer resulting in a ‘twist-chair’ conformation.
    Notes: Les quatre tétradeutério-1,1,4,4 diméthylamino-3 décalols-2 trans ont été synthétisés. L'examen des spectres de RMN de ces composés permet de confirmer la conformation ‘chaise aplatie’ de l'isomère cis à groupement diméthylamino axial et hydroxyle équatorial, tandis que les autres d'ammonium quaternaires on note également une déformation dans le cas du composé diaxial, cette déformation est accentuée dans l'iodure d'ammonium quaternaire cis N(CH3)3a OHe, conduisant à la conformation ‘chaise croisée’.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rotational barriers about the C—N bond of the N,N-dimethylamides of propiolic, methylpropiolic and phenylpropiolic acids have been determined by the iterative total line shape nuclear magnetic resonance method.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbon-13 magnetic resonance spectra of the s-cis and s-trans rotamers of enamino ketones and thiones of the general formula \documentclass{article}\pagestyle{empty}\begin{document}${\rm X =}\mathop {\rm C}\limits^{\rm 1} {\rm (}\mathop {\rm R}\limits^{\rm 1} {\rm)}\mathop {\rm C}\limits^{\rm 2} {\rm H =}\mathop {\rm C}\limits^{\rm 3} {\rm HN}\mathop {{\rm R}_{\rm 2}}\limits^{\rm 4}$\end{document} (where × = O or S and R-1, R-4 = alkyl) have been obtained. With dimethylaminoacrolein and its thione analogue, restricted rotation could only be observed in the latter. The chemical shift differences between rotamers and homologues are attributed to changes in conjugation and to induced bond polarisation, both these factors resulting from steric strain. In particular, nonplanar deformations of the s-trans rotamers are deduced from their C-2 chemical shift values.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 503-507 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The carbon-13 NMR spectra of 16 aliphatic phosphorus compounds with -PCl2, -P(OCH3)2, -P(CH3)2 or -PS(CH3)2 groups were determined and interpreted on the basis of the usual α, β-deshielding and γ-shielding effects. The α-effects of all the groups were quite large (15 to 30 ppm), though the β-effects were small (0 to 3 ppm). The γ-effects were also small (0·2 to 1·6 ppm), but of significance in suggesting reduced steric compression relative to that found for methyl and most of the common organic functional groups. This may be attributed to the greater length of the C—P bond. The phosphorus-31 NMR spectra of these compounds also show the existence of interaction with γ-carbons by exhibiting small additive upfield shifts.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 510-512 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Long range proton-proton coupling constants between H3exo and H5exo have been measured in a series of 4-substituted bornanones. Correlation between the magnitudes of 4J3exo-5exo and the inductive linear free energy σI has been obtained. 4-Substituted bornanone nitrimines exhibit diminished values of 4J3exo-5exo with respect to the parent ketone.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. i 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 513-514 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The chemical shift non-equivalence values (about 1 ppm) of the isopropyl methyl groups in the 1H and 13C NMR spectra of the compounds having structure 1 is interpreted as due to the existence of a highly preferred conformation.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 515-516 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The NMR spectra of pyridine, pyrazine and imidazole are examined in acetone-d6. The differential shifts of the ring protons are accounted for in terms of an interaction between the lone pair on the ring nitrogen atom and the carbonyl group of acetone.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. A9 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. A10 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974) 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The C—H proton NMR spectra of the twenty conceivable methyl and ethyl substituted hydrazines are presented and analyzed with respect to effects on chemical shifts of the C—H protons caused by replacement of hydrogen by methyl and ethyl groups on the C—N—N—C chain. Thirteen different methyl substituent effects and six different ethyl substituent effects are identified and evaluated. Most of the effects are shielding and in accordance with an electron-releasing inductive effect of alkyl groups. A deshielding effect (the ‘C—C bond effect’) is observed when a methyl group replaces the hydrogen on the carbon bearing the hydrogen in focus and primary hydrogen on the carbon bearing the hydrogen in focus and primary hydrogens become secondary, as observed in other systems. On the basis of their effects on the chemical shifts of methyl protons in CH3X, eighteen different hydrazyl groups (× = —NR1NR2R3) fall into three classes: I (R1 = H; R2, R3 = H or alkyl); II (R1 = alkyl; R2 and/or R3 = H); III (R1, R2 and R3 = alkyl), with slightly different electronegativities: 2·94, 2·83 and 2·74, respectively.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 525-527 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The chemical shifts of the aldehydic proton in furfural, thiophenealdehyde and benzaldehyde have been measured in fourteen solvents. The correlation of the chemical shifts of thiophenealdehyde and benzaldehyde is excellent (r = 0·996) while it is lower for furfural-benzaldehyde (r = 0·956). The long range coupling constant Jα5 of furiurai has been measured in twelve solvents and the rotameric mole fractions determined. The chemical shifts of individual rotamers are calculated and shown to correlate with benzaldehyde, (r = 0·992; 0·993). Only one rotamer is predominant for thiophenaldehyde in all solvents. The intrinsic solvent effects of the three aldehydes are similar.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The configuration of conformationally homogeneous epoxides in trans bicyclo-(n.3.0) alkanes is established by progressive complexation with Eu(dpm)3. The examples described demonstrate the importance of this method which is superior to all the other physicochemical methods already used to determine the cyclopentane epoxide configuration.
    Notes: La configuration de divers époxydes conformationnellement homogènes en série bicyclo-(n.3.0) alcanique trans est établie par compléxation progressive avec avec Eu(dpm)3. Les exemples décrits mettent en évidence l'importance de cette technique qui est très supérieure à tous les autres procédés physico-chimiques déjà mis en oeuvre pour déterminer la configuration des époxydes en série cyclopentanique.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 528-533 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Analysis of NMR spectra of different cyclic and acyclic imines, together with those obtained with the lanthanide shift reagent Eu(fod)3, allowed the characterisation of the syn-anti (Z-E) isomerism of these compounds. In one case, it was possible to demonstrate a syn-anti equilibration by adding Eu(fod)3.
    Notes: La combinaison de l'étude directe des spectres de RMN du proton et des déplacements induits par le complexe Eu(fod)3 a permis d'étudier les phénomènes d'isomérie syn-anti (Z-E) dans un certain nombre d'imines cycliques et acycliques. Un cas d'équilibration syn ⇌ anti par addition d'Eu(fod)3 a pu être mis en évidence.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 534-536 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1H NMR spectra of photodimers of cinnamic acid, chalcone and related compounds were analysed, and the spectral parameters and all the coupling constants were obtained. A clear differentiation among the head-to-head and head-to-tail stereoisomers can be obtained by considering the values of K, L, M and N parameters. The different types of hh and ht isomers can be immediately assigned by considering the relative values of the three-bond couplings. An authentic example of an A2B2 spin system is reported.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 540-541 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 13C chemical shifts and 13C—205Tl spin-spin coupling constants are reported for phenylthallium(III) bis(trifluoroacetate) and some of its mono- and dimethyl derivatives. The signs of nJ(13C, 205Tl) relative to n+1J(1H, 205Tl) are determined by offresonance decoupling of protons.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 537-539 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The proton NMR spectrum and carbon-13 satellites of partially oriented propyne give the complete structure of this molecule. Agreement with microwave results is excellent.
    Notes: Le spectre protonique ainsi que les satellites du carbone-13 du propyne orienté dans un solvant nématique permettent d'accéder à la structure complète de cette molécule. L'accord avec les résultats obtenus par spectroscopie micro-onde est excellent.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 542-543 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The high temperature 13C NMR spectra of the methyl esters of deuteroporphyrin-IX and protoporphyrin-IX, and octaethylporphyrin show sharp discrete signals for the inner macrocycle carbon resonances. The temperature dependence of these shifts is discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 544-546 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Some available methods for the analysis of lanthanide induced shift data have been examined. These methods are compared and evaluated using the data gathered from substituted phenyl tert-butyl carbinols.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The configuration of twenty-four different α,β-diaryl-α,β-dialkylpropionitriles has been determined using nuclear magnetic resonance spectra. The erythro form showed greater deshielding of the methine hydrogen and alkyl groups in its spectra than the corresponding threo isomer. The former, however, showed less deshielding of the aryl groups than the threo isomer. Infrared spectra were not suitable for assignments of configuration.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 552-555 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbon-13 spin-lattice relaxation times (T1) and 13C-{19F} nuclear Overhauser enhancement (NOE) factors have been measured for some simple fluorocarbons by pulse-Fourier transform methods - ‘progressive saturation’ and ‘dynamic Overhauser enhancement’. The NOE factors are shown to be large for 13C with directly bonded fluorines, and the values for T1 and the NOE factors are similar to those obtained elsewhere on the corresponding hydrocarbons.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Analysis of the 1H NMR spectrum of γ-hydroxypyridine dissolved in the lyotropic mesophase formed by a 14 : 1 : 1 : 20 mixture (by weight) of sodium dodecyl sulphate, decanol, sodium sulphate and D2O provides all the spectral parameters with reasonable precision. The chemical shift, the indirect and the direct proton-proton coupling constants are derived. The direct dipolar couplings thus determined are utilised to obtain the relative interproton distances. Information about the molecular orientation and the solvent solute interactions is deduced.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 565-567 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 19F and 31P NMR spectral parameters of a series of meta and para substituted phenylphosphonic difluorides were found to be linearly related to the substituent parameters: the phosphorus chemical shifts correlated with Hammett's σ constant, the fluorine chemical shifts with Taft's σR parameter and the phosphorus-fluorine coupling constants with σ+.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 577-579 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An analysis of both the aromatic and aliphatic portions of the 1H NMR spectrum of α-tetralone has been carried out. Two deuterated derivatives, 2,2-dideuterio- and 4,4-dideuterio-α-tetralone, were prepared to facilitate unambiguous assignment of chemical shifts for the aliphatic protons. The conformation of the 6-membered alicyclic ring of the molecule is defined by the coupling constants among the aliphatic protons. Benzylic coupling was the only detectable long range interaction between the aliphatic and aromatic protons of the molecule. The magnitude and sign of these coupling constants agree with previous calculations of Wasylishen and Schaefer.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 568-573 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The geometric factor G [G = (3 cos2 θ -1) r-3] of selected protons relative to a centre of co-ordination [Eu(dpm)3] is determined using Dreiding models of different conformers of 1,3-aza- and 1,3-oxaphospholanes. The centre of co-ordination is supposed to be joined to the oxygen of the carbonyl group or to the nitrogen and oxygen in the hetero-ring, respectively. The graphs of the geometric factors against the paramagnetic shifts of the relevant protons are straight lines only for the preferred conformers on the basis of a correct centre of co-ordination.As a measure for the paramagnetic shift of a proton the slope of the graph of chemical shift against the concentration of Eu(dpm)3 (in mol %) is chosen. By variation of the relative configuration at C-5 in the models and calculation of the geometric factor, it is possible to determine the different diastereomers, which are distinguished by the relative position of the substituent at phosphorus and C-5.
    Notes: An Dreiding-Modellen der verschiedenen Konformere von 1,3-Aza- und 1,3-Oxaphospholanen werden die Geometriefaktoren G [G = (cos2θ - 1)r-3] einzelner Protonen bezüglich eines Koordinationszentrums [Eu(dpm)3] bestimmt. Das Koordinationszentrum wird entweder an dem Sauerstoff der Carbonylgruppe oder an dem Stickstoff oder Sauerstoff im Heteroring gebunden angenommen. Die graphische Darstellung der Geometriefaktoren gegen die paramagnetischen Verschiebungen der betreffenden Protonen ergibt nur für die bevorzugten Konformere bei Zugrundelegung der richtigen Koordinationszentren Geraden. Als Maßzahl für die paramagnetische Verschiebung eines Protons wird die Steigung der Geraden gewählt, die sich beim graphischen Auftragen der chemischen Verschiebung gegen den Gehalt an Eu(dpm)3 (in Mol-%) ergibt. Durch Variation der relativen Konfiguration am C-Atom 5 an den Modellen und Berechnung der Geometriefaktoren ist es möglich, die unterschiedlichen Diastereomere zuzuordnen, die sich bezüglich der Substituentenstellung am Phosphor und am C-Atom 5 unterscheiden.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 580-582 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbon-13 chemical shifts of three arylmethyl carbanions have been determined by changing solvents and counter ions. The charge distributions in the carbanions are discussed and compared with those obtained from the 1H chemical shifts.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 583-585 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbon-13 NMR spectra have been obtained and analyzed for a series of saturated linear and cyclic sulfur-containing organic molecules. For the large cyclic polythiaethers whose proton spectra are broad and unresolved, it is found that carbon-13 spectra are sharp and well resolved. The resonances of all carbons fall within the expected chemical shift ranges. Based upon the comparative resolution in the spectra of large and small cyclic species, it is concluded that whatever conformational motion may exist within the rings must be occurring very rapidly on the NMR time scale.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 586-589 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 13C NMR spectra of unsubstituted 1,6,6aλ4-trithiapentalene and a series of methyl and phenyl substituted 1,6,6aλ4-trithiapentalenes have been recorded. The spectra have been assigned by comparison with 1H NMR data based on coupling constants from undecoupled spectra. From the chemical shift of C-3a it is concluded that the double bond character of the C-3a - S-6a is low. The relaxation times for C-2 and C-3 only show small differences; this seems not to be in favour of a fast interconversion between two thiocarbonyl forms. The NMR data obtained seem thus to be in accordance with a bicyclic naphthalene-like structure with ten delocalised π-electrons.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of a D/E cis isomer of the title compound is described. In an attempt to obtain the other D/E cis isomer, epimerisation reactions were studied. The configuration and conformation of the isomers are determined on the basis of their 1H NMR spectra. The shift of the 16b proton on N-9 protonation indicates the quinolizidine conformation. At 270 MHz, the ABCD system of the C-10 and C-11 methylenes can be analysed. The 2J(C-10H2), together with the multiplicity of H-8a, allows an unequivocal assignment of a cis-anti-cis structure to the only D/E cis isomer obtained.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 599-600 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 1H NMR spectra of thirteen dihydro-1,2-oxazine derivatives are reported. Spin decoupling allows analysis of the spectra, features of which include homoallylic couplings of +2 to +2·5 Hz, allylic couplings of -1·5 to -1·7 Hz and vicinal couplings across sp2 to sp3 carbon-carbon bonds of +2·9 to +3·7 Hz.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 601-602 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbon-13 NMR chemical shifts have been measured in a number of binary mixtures of normal alkanes. Intrinsic solvent shifts are deduced from the shifts and the relevance of some small substituent effects in alkanes is discussed. A comparison is made between solvent effects and thermally induced chemical shift differences in alkanes.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 603-611 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The carbon-13 NMR spectra of lanosta-8-en-3β-ol, lanosta-8, 24-dien-3β-ol, lanosta-7,9(11)-dien-3β-ol, lanostan-3β-ol, eupha-8-en-3β-ol, eupha-8,24-dien-3β-ol, ursa-12-en-3β-ol (α-amyrin) and oleana-12-en-3β-ol (β-amyrin) have been obtained and completely assigned. The results of this study provide chemical shift data for methyl, methylene, methine and quaternary carbon atoms in tetra- and pentacyclic triterpenoid spectra. The carbon-13 NMR spectrum of a triterpenoid provides a unique fingerprint for the molecule.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The correlation of JmetaFF in some 1-substituted-2,6-difluorobenzenes (1) with the bond order matrix of the fluorine 2p(π) orbitals provides information on the orientation of the substituents and the position of the counter-ion in the anilinium salt. The calculated charge densities in the analogous anilinium fluoride ion pair are compared with those of the free ion and neutral molecule.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: With t-BuO-/t-BuOH at 185°C bicyclo-[2.2.2] and -[3.2.1]octanones are interconvertible. In saturated systems equilibrium is attained very slowly, but in unsaturated cases an equilibrium mixture heavily favoring the [3.2.1] skeleton is obtained relatively rapidly, thereby providing a convenient route to homo and bis-homo conjugated ketones. Experiments in t-BuOD using 13C NMR to monitor deuterium incorporation revealed five major sites of exchange in the unsaturated ketones.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. A5 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974) 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 622-624 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The 240 MHz NMR spectra of bipyrimidine in the nematic phase of p-methoxybenzylidene-p-n-butylaniline is analysed. The para H,H inter-ring distance is determined. The barrier to internal rotation of the inter-ring C—C bond is studied. Excellent agreement between experimental and calculated spectra is obtained using potential function V(φ) = ½ ΣNVn (1 - cosn φ) with V1 = V2 = V3 = 0 cal mol-1 and V4 = 500 cal mol-1.
    Notes: Le spectre de RMN obtenu à 240 MHz pour la bipyrimidine orientée dans un solvant nématique p-métoxybenzylidène p-n-butyl aniline est analysé. La distance entre les hydrogènes en position para est déterminée. La barrière de potentiel s'opposant à la libre rotation autour de la liaison centrale C—C est étudiée. Un excellent accord est obtenu entre spectre calculé et spectre expérimental lorsqu'on utilise une fonction potentielle V(φ) = 1/2 ΣNVn (1 - cosn φ) avec V1 = V2 = V3 = 0 cal mol-1 et V4 = 500 cal mol-1.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The 1H NMR spectra of several 1,3,2-dioxaphosphorinanes bearing an extracyclic P—N bond have been analysed. The 3J(POCH) couplings are strongly dependent upon the orientation of the bond around the phosphorus atom. Depending upon the nature of the bonds attached to the nitrogen atom, the dioxaphosphorinane ring may adopt either a fixed chair conformation with the P—N bond in the axial or equatorial orientation, or it may be in equilibrium between two chair conformations where the P—N bond is alternately axial or equatorial. The equilibrium is fast on the NMR time scale.
    Notes: Le spectre de résonance magnétique nucléaire du proton de divers dioxaphosphorinanes-1,3,2, qui portent au niveau du phosphore une liaison P—N extracyclique a été analysé. Cette étude confirme que, pour une disposition géométrique donnée des atomes P, O, C et H, le couplage 3J(POCH) dépend fortement de l'orientation des liaisons au niveau du phosphore. Suivant la nature des restes attachés à l'atome d'azote, le cycle dioxaphosphorinane adopte une forme du type chaise rigide à liaison P—N axiale ou équatoriale, ou au contraire une forme chaise qui s'inverse rapidement pour le temps d'observation de la RMN.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The proton and carbon NMR spectra for a series of substituted indenes [C9H7R, R = H, CH3, Si(CH3)3] are reported. The proton and carbon resonances for the 5-membered ring exhibit pronounced changes as a function of the substituents.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. ii 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974) 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 144-150 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Activation parameters for the hindered rotation in some dimethylamino substituted azoles are reported and the effects of various ring systems and substituents on the barrier are discussed. Possible errors in ΔH≠ and ΔS≠ are investigated.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The NMR spectrum of acrolein and acroyl fluoride (CH2=CH—COX with X=H and F) oriented in a nematic phase has been measured and information about conformational equilibrium s-cis ⇄ s-trans has been obtained. The barrier to internal rotation of the COX group has been studied with various hypotheses. Good agreement between experimental and calculated spectra has been obtained using the potential equation V(φ) = ΣnVn(1 - cos nφ)/2, with V1 = -200 cal mol-1, V2 = 1500 cal mol-1 and V3 = 400 cal mol-1 for the fluorine compound, and V1 = 1200 cal mol-1, V2 = 3000 cal mol-1 and V3 = 2000 cal mol-1 for acrolein; this last compound is found to be mostly in the s-trans conformation.
    Notes: Les spectres RMN de l'acroléine et du fluorure d'acroyle (CH2=CH—COX avec X=H et F) orientés dans une phase nématique ont été interprétés et des informations sur l'équilibre conformationnel s-cis ⇄ s-trans ont été obtenues. La barrière s'opposant à la libre rotation du groupement COX a été étudiée à l'aide de différentes hypothèses. Un bon accord a été obtenu entre les spectres expérimentaux et les spectres calculés en utilisant une fonction potentiel V(φ) = ΣnVn(1 - cos nφ)/2, avec V1 = -200 cal mol-1, V2 = 1500 cal mol-1 et V3 = 400 cal mol-1 pour le composé fluoré; et V1 = 1200 cal mol-1, V2 = 3000 cal mol-1 et V3 = 2000 cal mol-1 pour l'acroléine; ce dernier composé existe presque exclusivement sous la forme s-trans.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The NMR spectra of trans-3,4-dimethylcyclopentanone and trans-3,4-dimethyl-2,2,5,5-tetradeuteriocyclopentanone are analysed. The coupling constants, calculated for the deuterated compound, are in good agreement with a diequatorial conformation of the methyl groups.
    Notes: Les spectres RMN de la diméthyl-3,4 cyclopentanone trans et de la diméthyl-3,4 tétradeutério 2,2,5,5 cyclopentanone-trans ont été analysés. Les constantes de couplage, déterminées pour le composé deutérié, sont en faveur d'une conformation diéquatoriale des groupements méthyle.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: We propose a new method for calculating 1H and 19F chemical shifts in saturated organic compounds. Results show that the shifts are a balance of several contributions and allow an evaluation of these effects: a diamagnetic contribution d( - ∊) proportional to the net charge ∊ of the electronic environment of the nucleus considered and paramagnetic contributions pX of each of substituents, constant attached to the substituent X in any molecule. For both nuclei, d values were deduced from a theoretical calculation of the screen in the free atom. This method, using a restricted number of parameters obtained from experiment, lead to the observed chemical shifts with a mean accuracy of ± 0,32 ppm for 1H and ± 11 ppm for 19F. Therefore this method gives a simple quantitative relation between chemical shift and structure from which precise indications about the origin of the contributions from neighbouring electronic surroundings can be obtained.
    Notes: Nous proposons une nouvelle méthode de calcul du déplacement chimique de 1H et de 19F dans les molécules organiques saturées. Les résultats obtenus montrent que celui-ci est le bilan de plusieurs contributions et permettent une évaluation de celles-ci: une contribution diamagnétique d( - ∊) proportionnelle à la charge nette ∊ de l'environnement électronique du noyau étudié et des contributions paramagnétiques pX de chacun des substituants géminés, constantes pour chaque substituant X lorsqu'on passe d'une molécule à une autre. Pour les deux noyaux, les valeurs de d utilisées sont déduites des calculs théoriques de l'écran dans l'atome libre. Cette méthode, qui n'utilise qu'un nombre très restreint de paramètres déduits de l'expérience nous a permis de retrouver les déplacements chimiques expérimentaux avec un écart moyen, pour 1H de ± 0,32 ppm, pour 19F de ± 11 ppm. Elle a donc l'interêt de fournir une relation quantitative simple entre déplacement chimique et structure permettant de dégager des indications précises sur l'origine des contributions des environnements voisins.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 13C spectra of α-thujene (1), isothujone (2), (-)isothujol (3), (+)neoisothujol (4), sabinol (5), dihydroumbellulone (6) and umbellulone (7) and the alcohol acetates are recorded and assigned. The C-6 chemical shift may be used in conjunction with the steric shift mechanism as a conformational probe in these molecules. The results obtained indicate that isothujol, neoisothujol, isothujone and dihydroumbellulone adopt boat-like conformations whilst sabinol has a much flatter conformation. Conjugation of the isolated double bond of α-thujene and the carbonyl group of dihydroumbellulone with the cyclopropane ring has virtually no effect on the 13C shifts, but those of umbellulone itself are anomalous, indicating conjugation of the α,β unsaturated ketone system with the cyclopropyl ring.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 240-244 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A relatively fast rotation around the α,β carbon-carbon double bond at the equilibrium of geometrical isomers and a comparatively slow rotation around the carbon-nitrogen single bond in compounds of the type \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm X}_1 ({\rm X}_2){\rm C}_{\rm \alpha}=\!={\rm C}_\beta {\rm H}-{\rm C}_\gamma {\rm H}=\!={\rm C}_\delta {\rm H}-{\rm N}({\rm R}_1){\rm R}_2 $$\end{document} (X1, X2 are electron-attracting substituents) were detected and investigated by the NMR technique. The relationships between the free energies of activation for these rotational processes and the character of the substituents, the number of double bonds, solvents and concentration were studied.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. A5 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 245-249 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The proton NMR spectra of the carbanions of xanthene [XH]- and thioxanthene [TxH]- have been recorded and interpreted. Paratropism in the central rings of [XH]- and [TxH]- is inferred from a comparison of the chemical shifts with those of the carbanion of 9,10-dihydroanthracene [AH]-. The contributions to the chemical shifts arising from n-electron excess charges, local dipoles and magnetic anisotropies are discussed. Numerical values for the various ring currents have been estimated by a least squares analysis of the observed chemical shifts after applying corrections for the excess charge effect. The results point to a strongly increasing paramagnetic ring current in the central ring in the order [AH]-, [TxH]-, [XH]-.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 6 (1974), S. 253-258 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The nuclear magnetic resonace spectra of six pyridocyanines, four azapyridocyanines, one monoquaternized 2,4′-dipyridylamine and two dipyridylamines were measured and fully analyzed. The spectra of the 2,2′-pyrido- and azapyridocyanines support previously published results that these dyes exist in the all-trans form and not in the mono-cis form, as stated by others. Strong evidence was obtained that N,N′-ethylene-2,2′-pyridocyanine is twisted. The spectra of dyes with p-connected pyridine rings indicate that these nuclei may rotate around the bond between the meso group and the p-position. Relative chemical shifts in the spectra of the homologous pyrido- and azapyridocyanines can be explained by electronic effects rather than by magnetic anisotropy of the aza group or changes in ring currents.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...