ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Digitale Medien

Spectroscopic CNDO/CI study of some cyclic polyenes (1980)

Zuccarello, Felice ; Buemi, Giuseppe ; Raudino, Antonio

New York, NY [u.a.] : Wiley-Blackwell

Journal of Computational Chemistry 1 (1980), S. 341-347

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0192-8651

Schlagwort(e): Computational Chemistry and Molecular Modeling ; Biochemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Informatik

Notizen: CNDO/S calculations are carried out on 1,3,5-cycloheptatriene (I), 1,3,5,7-cyclooctatetraene (II), all-cis-1,3,5,7-cyclononatetraene (III), and all-cis-1,4,7-cyclononatriene (IV), for which π-σ separability is a questionable matter. When disparate choices are available for the geometries, preferences are based on the agreement between calculated and experimental spectra. The microwave structure for I and an unsymmetrical conformation for III are suggested. In the electronic spectra, conjugative contributions are assigned to the lowest-energy weak band, while an ethylenic nature is to be attributed to the intense band in the range of 6 eV. The possibility of through-space π interactions is examined qualitatively. An appreciable degree of such interaction is shown by IV.

Zusätzliches Material: 1 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jcc.540010405

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

2

Digitale Medien

An Ab initio study on the conformations of protonated, neutral, and deprotonated amidine (1982)

Zielinski, Theresa Julia ; Peterson, Michael R. ; Csizmadia, Imre G. ; [weitere]

New York, NY [u.a.] : Wiley-Blackwell

Journal of Computational Chemistry 3 (1982), S. 62-68

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0192-8651

Schlagwort(e): Computational Chemistry and Molecular Modeling ; Biochemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Informatik

Notizen: Ab initio SCF molecular orbital calculations have been performed to ascertain the conformational preferences of protonated, neutral, and deprotonated amidine [HC(=NH)NH2], using the 3-21G split valence basis set. The states of eight stable species, eight transition states, and four higher-order saddle points have been determined by complete geometry optimization utilizing analytic energy gradient techniques. Protonation at the amidine =NH is preferred over the -NH2 site by 37.1 kcal/mol. Neutral amidine has rotational barriers of 9.6 and 11.7 kcal/mol for the HN=CN cis and trans isomers, respectively, while all the stable HC(NH2)2+ and HC(NH)2- species possess torsional barriers larger than 23 kcal/mol. There is, however, essentially free C - N single-bond rotation in HC(=NH)NH3+, the calculated barriers being 0.7 and 1.8 kcal/mol for the cis and trans HN=CN isomers, respectively.

Zusätzliches Material: 6 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jcc.540030111

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

3

Digitale Medien

Conformational study of protonated, neutral, and deprotonated formamide (1982)

Zielinski, Theresa Julia ; Poirier, Raymond Alcide ; Peterson, Michael Roy ; [weitere]

New York, NY [u.a.] : Wiley-Blackwell

Journal of Computational Chemistry 3 (1982), S. 477-485

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0192-8651

Schlagwort(e): Computational Chemistry and Molecular Modeling ; Biochemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Informatik

Notizen: Neutral, protonated, and deprotonated formamide isomers were studied at the 3-21G SCF level with complete geometry optimization. Ten stable structures, ten first-order saddle points, and three second-order saddle points (conformational maxima) are reported. [Total energies are reported in hartrees (1 hartree = 627.51 kcal/mol = 2625.5 kJ/mol) and energy differences are reported in kJ/mol (1 kJ/mol = 0.239 kcal/mol).] Rotational barriers and proton affinities are discussed and compared to isoelectronic amidine species.

Zusätzliches Material: 9 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jcc.540030405

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

4

Digitale Medien

Uracil-4-Hydroxyuracil tautomerism revisited (1983)

Zielinski, Theresa Julia

New York, NY [u.a.] : Wiley-Blackwell

Journal of Computational Chemistry 4 (1983), S. 345-349

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0192-8651

Schlagwort(e): Computational Chemistry and Molecular Modeling ; Biochemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Informatik

Notizen: The tautomerism of the uracil-4-hydroxyuracil system is examined with the 3-21G basis set and full geometry optimization using gradient techniques. Single-point calculations at the 6-31G level were also done and the results compared with the 2-pyridone-2-hydroxypyridine system. The best ΔE(taut) obtained in this work is 74.1 kJ/mol.

Zusätzliches Material: 2 Tab.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jcc.540040309

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

5

Digitale Medien

Examination of formamide, formamidic acid, amidine dimers, and the double proton transfer transition states involving these dimers (1984)

Zielinski, Theresa Julia ; Poirier, Raymond Alcide

New York, NY [u.a.] : Wiley-Blackwell

Journal of Computational Chemistry 5 (1984), S. 466-470

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0192-8651

Schlagwort(e): Computational Chemistry and Molecular Modeling ; Biochemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Informatik

Notizen: Structures and relative energies were obtained for the hydrogen bonded dimers of formamide and formamidic acid using the 3-21G basis set. A double proton transfer transition state is claimed to link these two dimers. While the structure of the transition state was intermediate between those of the two dimers, the energy was only 7.6 kJ/mol greater than the less stable formamidic acid dimer. The activation energy from the formamide dimer side of the reaction was found to be 125 kJ/mol of dimer. A similar transition state was found for the amidine dimer system. The activation energy for this model reaction was found to be 66.9 kJ/mol of dimer.

Zusätzliches Material: 2 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jcc.540050507

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

6

Digitale Medien

A water-mediated tautomerism mechanism in formamide and amidine. An ab initio study (1983)

Zielinski, Theresa Julia ; Poirier, Raymond Alcide ; Peterson, Michael Roy ; [weitere]

New York, NY [u.a.] : Wiley-Blackwell

Journal of Computational Chemistry 4 (1983), S. 419-427

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0192-8651

Schlagwort(e): Computational Chemistry and Molecular Modeling ; Biochemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Informatik

Notizen: Formamide, formamidic acid, and amidine water complexes were studied using 3-21G fully optimized structures and 6-31G energies. Hydrogen bonding and a water-mediated tautomerism mechanism were examined. The optimized complexes show that relaxation of the monomers has occurred. Hydrogen bond lengths and energies fall within the range of values found using other basis sets and other comparable systems.

Zusätzliches Material: 4 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jcc.540040318

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

7

Digitale Medien

A model of the kinetics of blood levels of phenazepam and its metabolite 3-hydroxyphenazepam in cats (1982)

Zherdev, V. P. ; Ékonomov, A. L. ; Brestkina, L. M. ; [weitere]

Springer

Bulletin of experimental biology and medicine 94 (1982), S. 1373-1375

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1573-8221

Schlagwort(e): pharmacokinetics ; phenazepam ; 3-hydroxyphenazepam ; cats ; blood ; metabolic model

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie , Medizin

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00827203

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

8

Digitale Medien

Comparison of the RHF, NDDO, and MOM molecular one-electron expectation values calculated using minimum basis sets with Slater, Burns, Clementi, and BLMO exponents (1984)

Zeiss, G. D. ; Whitehead, M. A.

New York, NY [u.a.] : Wiley-Blackwell

Journal of Computational Chemistry 5 (1984), S. 207-215

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0192-8651

Schlagwort(e): Computational Chemistry and Molecular Modeling ; Biochemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Informatik

Notizen: The effect of different exponents, Slater, Burns, Clementi, and Best Limited Molecular Orbital (BLMO) on the approximate one-electron property expectation values from minimum basis-set calculations is reported for Roothaan-Hartree-Fock (RHF), neglect of diatomic differential overlap (NDDO), and maximum overlap method (MOM) calculations on FH, CO, and LiH.

Zusätzliches Material: 2 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jcc.540050214

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

9

Digitale Medien

Comparison of RHF, NDDO, and MOM molecular one-electron expectation values calculated using weighted and unweighted STO-NG (ω) basis functions (1983)

Zeiss, G. D. ; Whitehead, M. A.

New York, NY [u.a.] : Wiley-Blackwell

Journal of Computational Chemistry 4 (1983), S. 48-52

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0192-8651

Schlagwort(e): Computational Chemistry and Molecular Modeling ; Biochemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Informatik

Notizen: The effect of basis functions on molecular one-electron property expectation values calculated by approximate methods is examined using weighted and unweighted least-squares Gaussian-type orbital function expansions of Slater-type orbital functions.

Zusätzliches Material: 2 Tab.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jcc.540040108

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

10

Digitale Medien

Standard deviation in reduced errors (SDRE): A criterion to assess the relative overall quality of approximate wavefunctions (1983)

Zeiss, G. D. ; Whitehead, M. A.

New York, NY [u.a.] : Wiley-Blackwell

Journal of Computational Chemistry 4 (1983), S. 150-153

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0192-8651

Schlagwort(e): Computational Chemistry and Molecular Modeling ; Biochemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Informatik

Notizen: The standard deviation in reduced errors (SDRE) quantitatively measures the similarity between an approximate and exact wavefunction. It is the Euclidean distance between the vector of the one-electron property expectation values calculated using the approximate and exact expectation values.

Zusätzliches Material: 2 Tab.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jcc.540040205

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext