E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Special Issue "Nuclear Magnetic Resonance Spin-Spin Coupling Constants - Calculations and Measurements - Part II"

Quicklinks

A special issue of International Journal of Molecular Sciences (ISSN 1422-0067). This special issue belongs to the section "Physical Chemistry, Theoretical and Computational Chemistry".

Deadline for manuscript submissions: closed (31 December 2002)

Special Issue Editor

Guest Editor
Prof. Dr. Stephan P. A. Sauer

Physical Chemistry Section Department of Chemistry University of Copenhagen Universitetsparken 5 DK-2100 Copenhagen, Denmark
Website | E-Mail
Phone: +45 35 32 02 68
Interests: quantum chemistry; electron correlation; ab initio calculations of molecular properties: NMR indirect nuclear spin-spin coupling; NMR chemical shift; polarizability; ESR hyperfine coupling; electronic excitation energy; oscillator strength; rotational g-f

Published Papers (5 papers)

View options order results:
result details:
Displaying articles 1-5
Export citation of selected articles as:

Research

Open AccessArticle Extension of the Karplus Relationship for NMR Spin-Spin Coupling Constants to Nonplanar Ring Systems: Pseudorotation of Tetrahydrofuran
Int. J. Mol. Sci. 2003, 4(4), 158-192; doi:10.3390/i4040158
Received: 14 September 2002 / Accepted: 10 December 2002 / Published: 4 April 2003
Cited by 24 | PDF Full-text (843 KB)
Open AccessArticle Through-Space Spin-Spin Coupling In Acetylenic Systems. Ab Initio and DFT Calculations
Int. J. Mol. Sci. 2003, 4(4), 193-202; doi:10.3390/i4040193
Received: 30 September 2002 / Accepted: 5 November 2002 / Published: 4 April 2003
Cited by 3 | PDF Full-text (223 KB) | HTML Full-text | XML Full-text
Open AccessArticle Electronic Mechanisms of Intra and Intermolecular J Couplings in Systems with C-H···O Interactions
Int. J. Mol. Sci. 2003, 4(4), 203-217; doi:10.3390/i4040203
Received: 15 October 2002 / Accepted: 19 November 2002 / Published: 4 April 2003
Cited by 2 | PDF Full-text (229 KB) | HTML Full-text | XML Full-text
Abstract
Correlation effects on the change of 1J(CH) couplings in model systems I:NCH...H2O and II:CH4...H2O as a function of the H...O distance are discussed. RPA and SOPPA results follow a similar trend in system II. In system
[...] Read more.
Correlation effects on the change of 1J(CH) couplings in model systems I:NCH...H2O and II:CH4...H2O as a function of the H...O distance are discussed. RPA and SOPPA results follow a similar trend in system II. In system I RPA values decrease monotonously as the H...O distance decreases, while SOPPA ones exhibit flat maximum near equilibrium. Such different behavior is ascribed to the π-transmitted component. Intermolecular couplings at the equilibrium geometry of I are analyzed by means of the CLOPPA approach. The larger absolute value of 2hJ(CO) compared to 1hJ(HO) is found to arise from contributions involving a vacant LMO localized in the C-H...O moiety. Full article
Open AccessArticle Electric Field Effects on 2JHH Spin-Spin Coupling Constants
Int. J. Mol. Sci. 2003, 4(4), 218-230; doi:10.3390/i4040218
Received: 18 October 2002 / Accepted: 2 January 2003 / Published: 4 April 2003
Cited by 5 | PDF Full-text (97 KB) | HTML Full-text | XML Full-text
Abstract
Some calculations of the electric field derivative of the spin-spin coupling constant on molecules in the series CH3F, CH3Cl, CH3Br, CH3I, CH4, CH3Li, CH3Na and CH3K have
[...] Read more.
Some calculations of the electric field derivative of the spin-spin coupling constant on molecules in the series CH3F, CH3Cl, CH3Br, CH3I, CH4, CH3Li, CH3Na and CH3K have been presented. The data is broken down into the 4 terms of the Ramsey theory: Fermi contact (FC); diamagnetic spin-orbit (DSO); paramagnetic spinorbit (PSO) and spin-dipolar (SD). The FC term is seen to dominate all the calculated Js and their derivatives presented here. The situation where the FC term does not dominate in other molecules is discussed as a contrast. Full article
Open AccessArticle The Effect of Substituents on Indirect Nuclear Spin-Spin Coupling Constants: Methan- and Ethanimine, Methanal- and Ethanaloxime
Int. J. Mol. Sci. 2003, 4(4), 231-248; doi:10.3390/i4040231
Received: 28 October 2002 / Accepted: 17 February 2003 / Published: 4 April 2003
Cited by 13 | PDF Full-text (139 KB) | HTML Full-text | XML Full-text
Abstract
Ab initio calculations of the spin-spin coupling constants have been carried out for methan- and ethanimine, methanal- and ethanaloxime at the level of the second order polarization propagator approximation with coupled cluster singles and doubles amplitudes (SOPPA(CCSD)) using the aug-cc-pVTZ-J basis sets. Previously
[...] Read more.
Ab initio calculations of the spin-spin coupling constants have been carried out for methan- and ethanimine, methanal- and ethanaloxime at the level of the second order polarization propagator approximation with coupled cluster singles and doubles amplitudes (SOPPA(CCSD)) using the aug-cc-pVTZ-J basis sets. Previously we have shown that this method can reproduce quantitatively the coupling constants for methanimine; our new results for methanal- and ethanaloxime agree also very well with the measured couplings. A study of both purely geometrical and substituent effects on all coupling constants in the title compounds is presented. Analyzing the four contributions to the coupling constants we find that the stereoelectronic effect of the nitrogen lone pair on the one-bond C-H and C-C couplings as well as the corresponding effect for the geminal N-H and N-C couplings is affected strongly by the -OH substituent. For the one-bond C-N couplings we observe that the orbital paramagnetic (OP) contribution is comparable to the Fermi Contact (FC) contribution but opposite in sign and that the spin-dipolar (SD) term amounts to between 40% and 85% of the total coupling constants. Changes in the total one-bond C-N couplings caused by the -OH substituent are also almost entirely due to SD contribution. Full article

Journal Contact

MDPI AG
IJMS Editorial Office
St. Alban-Anlage 66, 4052 Basel, Switzerland
ijms@mdpi.com
Tel. +41 61 683 77 34
Fax: +41 61 302 89 18
Editorial Board
Contact Details Submit to IJMS
Back to Top