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  • Chemistry  (12)
  • Analytical Chemistry and Spectroscopy  (8)
  • 13C NMR  (1)
  • 1
    Electronic Resource
    Electronic Resource
    On the reaction of catenapoly(diphenoxy-λ5-phosphazene) with sulfur trioxide (1989)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 190 (1989), S. 191-202 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The reaction of catenapoly(diphenoxy-λ5-phosphazene) (1) with SO3 in 1,2-dichloroethane at 15°C, applying a mole ratio m = [SO3]/[--P(OC6H5)2N - ] ≤ 1,0 and subsequent quenching with water, leads to catenapoly(diphenoxy-λ5-phosphazene-co-diphenoxy-λ5-phosphazenium hydrogen sulfate) (2) containing up to 57% protonated nitrogen. At m 〉 1,0 C-sulfonation occurs, resulting in the formation of water-soluble catenapoly[diphenoxy-λ5-phosphazene-co-diphenoxy-λ5-phosphazenium hydrogen sulfate-co-bis(sulfophenoxy)-λ5-phosphazenium hydrogen sulfate] (3). The latter can be converted into catenapoly[diphenoxy-λ5-phosphazene-co-bis(sulfophenoxy)-λ5-phosphazene] (4b) by treatment with alkali and subsequent percolating through a cation exchange resin. Analytical results show that C-sulfonation is preceded by the formation of a polymer-SO3 donor-acceptor complex.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1989.021900120
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  • 2
    Electronic Resource
    Electronic Resource
    Solid State and Solution Conformation of 6-[4-[N-tert-ButoxycarbonylN-(N′-ethyl)propanamide]imidazolyl]-6-deoxycyclomaltoheptaose: Evidence of Self-Inclusion of the Boc Group within the β-Cyclodextrin Cavity (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 1065-1076 
    Details
    ISSN: 1434-193X
    Keywords: Cyclodextrins ; Inclusion compounds ; Carcinine ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A new modified β-cyclodextrin (β-CD) derivative 1 that was functionalized in position 6 with Boc-Carcinine was synthesised and its crystal structure was determined. The structure reveals a “sleeping swan”-like shape, the covalently bonded Boc-Carcinine moiety forming a folded structure with the Boc group inserted within the hydrophobic cavity of the β-cyclodextrin. The conformation of the Carcinine moiety is determined by the inclusion of the Boc group and is further stabilised by three intramolecular hydrogen bonds, two between the amide N1-H group, the carbonyl C′1=O1 group and a primary hydroxylic group of the glucose unit 5, one between the carbonyl C′0=O0 group and the primary hydroxylic group of the glucose unit 2. The β-CD macrocycle differs only slightly from unmodified β-CDs, maintaining an approximate sevenfold symmetry. The solution structure of the new β-CD derivative was investigated by NMR spectroscopy and circular dichroism (c.d.) spectroscopy. In addition to a complete (1H and 13C) assignment of the pendant Boc-Carcinine group, the NMR study allowed the assignment of all the proton resonances associated with the β-CD macrocycle. Furthermore, NMR and c.d. results indicated that the self-inclusion of the Boc group within the β-CD cavity is retained in aqueous solution. In order to estimate the strength of this self-inclusion complex a series of competition experiments with the external guest 1-adamantanol was carried out using c.d. spectroscopy.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Preparation of trimethyl-2-hydroxyethylarsonium (arsenocholine) compounds (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 1 (1987), S. 403-412 
    Details
    ISSN: 0268-2605
    Keywords: Trimethyl-2-hydroxyethylarsonium salts ; arsenocholine ; trimethyl-2-haloethylarsonium bromide ; trimethyl-2-acetoxyethylarsonium bromide ; acetylarsenocholine ; trimethyl-2-(dihydrogen phosphato)ethylarsonium bromide ; 1H and 13C NMR spectra ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Trimethyl-2-X-ethylarsonium salts (X=OH, Cl, Br, CH3COO; anion=Br) and trimethyl-2-diethoxyethylarsonium bromide were prepared from trimethylarsine and the appropriate organic bromides in sealed tubes at elevated temperatures or by refluxing the neat reagents. The yields ranged from 33 to 85%. Anion exchange reactions produced the arsonium iodides, nitrates, acetates, tosylates, tetraphenylborates, picrates, hydroxides, and carbonates. Arsenocholine bromide (X=OH) was phosphorylated with concentrated phosphoric acid. The product was isolated as the barium salt. Treatment of the barium salt with sulfuric acid yielded trimethyl-2-(dihydrogen phosphato)ethylarsonium bromide. These substances were synthesized to serve as precursors for arsenic- containing phospholipids and as standards for the chromatographic identification of arsenocholines. The synthesized compounds were characterized by elemental analyses and 1H and 13C NMR spectroscopy. The shifts of the arsenic compounds were compared with those of the corresponding nitrogen compounds and found to be sufficiently different to be used for the identification of these compounds in their mixtures.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aoc.590010504
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  • 4
    Electronic Resource
    Electronic Resource
    The 250 MHz 1H NMR spectrum of cinnoline (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 504-507 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The proton NMR spectrum of cinnoline has been measured at high field (250 MHz) and analysed as an H-8-de-coupled ABCXY and H-4-decoupled ABCX system. Inter-ring H—H couplings have been determined and discussed in relation to theoretical values obtained using INDO calculations.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270071009
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  • 5
    Electronic Resource
    Electronic Resource
    Carbon-13 n.m.r. and CNDO/S study of 1,3-indandione and heterocyclic analogues (1976)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 8 (1976), S. 457-460 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 13C n.m.r. spectra are reported for 1,3-indandione, phthalic anhydride, thiophthalic anhydride, and phthalimide in chloroform-d solution. The 13C chemical shifts have also been calculated by means of Pople's perturbation theory using CNDO/S wave functions; the agreement between theoretical and experimental values is improved when an empirical charge-dependent term is added to the calculated diamagnetic and paramagneitc contributions.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270080906
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  • 6
    Electronic Resource
    Electronic Resource
    Carbon-13 n.m.r. and CNDO/S study of 1,2-indandione and heterocyclic analogues (1977)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 9 (1977), S. 401-403 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 13C n.m.r. spectra are reported for 1,2-indandione, coumarandione and thionaphthenequinone in CDCl3 solution and for isatin in dimethyl sulphoxide solution. The chemical shifts are assigned and discussed in connection with the influence of the heteroatom on the dicarbonyl group and the aromatic ring. The 13C shieldings have also been calculated by means of Pople's perturbation theory using CNDO/S wave functions.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270090706
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  • 7
    Electronic Resource
    Electronic Resource
    1H and 13C NMR spectra, 13C NMR relaxation times and molecular modelling studies of the narcotic agonist-antagonist α-( - )-N-propynylnormetazocine (1992)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 30 (1992), S. 20-29 
    Details
    ISSN: 0749-1581
    Keywords: N-Propynylnormetazocine ; Conformation ; Relaxation times ; Motional analysis ; Molecular Modelling ; 1H and 13NMR spectra ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The analysis of high-frequency 1H and 13C NMR spectra and both 1H—1H homonuclear and 1H—13C heteronuclear chemical shift correlation experiments indicate that N-propynlnormetazocine (NPMH+) is configurationally heterogeneous in solution, with the N-equatorial isomer being more populated than the N-axial isomer. The experimental proton-proton coupling constants measured for both diastereoisomers were in agreement with the calculated values for a chair conformation of the piperidine ring. AM1 and MM2 theoretical calculations both indicated the chair conformation as that preferred by the piperidine ring, and the N-equatorial isomer as being energetically favoured with respect to the N-axial form. The best fit of the 13C T1 relaxation time data and the related motional analysis of NPMH+ was carried out using the anisotropic model of reorientation with superimposed internal motion. The results showed an increase of the rotational anisotropy of the molecule on passing from the gas phase to the solution state.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260300106
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  • 8
    Electronic Resource
    Electronic Resource
    Reorientational dynamics and internal mobility of the mixed agonist-antagonist opioid narcotic cyclazocine by 13C NMR relaxation times (1993)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 31 (1993), S. 823-828 
    Details
    ISSN: 0749-1581
    Keywords: Cyclazocine ; 13CNMR ; Relaxation times ; Reorientational dynamics ; Internal mobility ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The motional behaviour of the mixed agonist-antagonist opioid narcotic cyclazocine (2-cyclopropylmethyl-2′-hydroxy-5,9-dimethyl-6,7-benzomorphan) as a cationic species (CLZH +) was analysed by 13C NMR spin-lattice relaxation times (T1). Both AM1 and MM2 theoretical calculations were performed to predict the preferred conformations and torsional energetics of CLZH+ in the vapour phase. The analysis of the experimental T1 data (in aqueous solution) was performed by using an analytical model to describe the overall and internal motions of the molecule. The best fit of the relaxation times allowed the detection, in the liquid phase, of effective solute-solvent interactions and the fully anisotropic diffusive process of the molecule. The motional parameters obtained indicated an increased retational anisotropy of CLZH+ on passing from the gas phase to the solution state. Different activation energies arising from separate solvation effects were found for the motion of the 10-Me and 11-Me groups. The fitted energies and transition energies matrix relative to the internal motion of the N-cyclopropylmethyl group indicated that the preferred conformational states are not isolated and that the overall and internal motions are of the same order of magnitude.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260310906
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  • 9
    Electronic Resource
    Electronic Resource
    1H and 13C NMR spectra of rac-2,3-bis(palmitoyloxy)propyl(2-trimethylarsonioethyl)phosphonate, an arsenic-containing phosphonolipid (1990)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 28 (1990), S. 856-861 
    Details
    ISSN: 0749-1581
    Keywords: Arsenolipid ; 2D NMR ; 1H and 13C NMR ; 31P arsenophosphonolipid ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 1H (500 MHz), 13C (300 MHz) and 31P (202 MHz) NMR spectra of rac-2,3-bis(palmitoyloxy)propyl(2-trimethylarsonioethyl)phosphonate were recorded in CDCl3 (3 M) solution. Homonuclear 1H-1H and heteronuclear 13C-1H chemical shift correlation experiments (COSY) were performed. All resonances were assigned. The shifts of the arsenic-containing phosphonolipid were compared with the shifts of the N-containing phospholipids. The most significant shift differences were found for the groups directly bonded to arsenic. Spectral evidence was indicative of free rotation about the —CH2 —CH2 —bond in the arsenocholine fragment.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260281004
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  • 10
    Electronic Resource
    Electronic Resource
    High-field NMR techniques and molecular modelling in the study of the inclusion complex of the cognition activator suronacrine (HP-128) with cyclodextrins (1993)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 31 (1993), S. 455-460 
    Details
    ISSN: 0749-1581
    Keywords: Cognition activator drugs ; Inclusion complexes ; Cyclodextrins ; NMR-ROESY ; Molecular modelling ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The structural features of the inclusion complexes of cyclodextrins (CDs) with the chiral cognition activator drug (±)9-[(phenylmethyl)amino]-1,2,3,4-tetrahydroacridin-1-ol maleate (suronacrine maleate, HP-128) were studied using both high-resolution 1H NMR spectroscopy and molecular modelling methods. The partial inclusion of the guest from the secondary hydroxyl side of α-CD was demonstrated in aqueous solution, in addition to a higher degree of penetration into the cavity of β-CD from the same side. NMR-ROESY experiments allowed the unambiguous location of the benzylic ring of the guest inside the β-CD cavity. The formation of diastereoisomeric pairs was demonstrated by the duplication of the benzylic proton signals. Molecular mechanics calculations were used to complement the NMR analysis. Molecular modelling procedures (MacroModel interactive computer program) allowed the prediction of the most stable structures of the complexes, and showed that specific site interactions, provided by hydrogen bond formation, are capable of differentiating the diastereoisomeric intramolecular inclusion complexes according to available experimental NMR data.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260310508
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