Analysis of long-range NMR spin-spin coupling in polyenes and the π-mechanism

Jürgen Gräfenstein, Tell Tuttle, Dieter Cremer

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

The J-OC-PSP (decomposition of J into Orbital Contributions using Orbital Currents and Partial Spin Polarization) method is applied to analyze NMR spin-spin coupling constants in polyenes, which were calculated using coupled perturbed density functional theory in connection with the B3LYP hybrid functional and a [7s,6p,2d/4s,2p] basis set. The analysis revealed that the π-mechanism for Fermi contact (FC) spin coupling is based on passive π-orbital contributions. The π-orbitals transfer spin information between σ orbitals (spin-transport mechanism) or increase the spin information of a σ orbital by an echo effect. The calculated FC(π) values are rather constant for small polyenes ranging between 3.5-5.5 Hz for a double bond. They decay more slowly with the distance between perturbing and responding nucleus than the σ contributions to the FC term. The sign of the passive FC(π) contribution can be assessed from a Dirac vector model. The limits for longrange coupling in a polyene were determined and their practical implications discussed.

LanguageEnglish
Pages452-462
Number of pages11
JournalPhysical Chemistry Chemical Physics
Volume7
Issue number3
Early online date12 Jan 2005
DOIs
Publication statusPublished - 7 Feb 2005

Fingerprint

Polyenes
spin-spin coupling
Nuclear magnetic resonance
orbitals
nuclear magnetic resonance
Orbital transfer
Spin polarization
Density functional theory
pressure sensitive paints
transfer orbits
Decomposition
electric contacts
echoes
density functional theory
decomposition
nuclei
decay
polarization

Keywords

  • decomposition
  • spin-spin coupling constants
  • SSCCs
  • Fermi contact spin coupling

Cite this

@article{f121de77c64843f8afca70b9185680d1,
title = "Analysis of long-range NMR spin-spin coupling in polyenes and the π-mechanism",
abstract = "The J-OC-PSP (decomposition of J into Orbital Contributions using Orbital Currents and Partial Spin Polarization) method is applied to analyze NMR spin-spin coupling constants in polyenes, which were calculated using coupled perturbed density functional theory in connection with the B3LYP hybrid functional and a [7s,6p,2d/4s,2p] basis set. The analysis revealed that the π-mechanism for Fermi contact (FC) spin coupling is based on passive π-orbital contributions. The π-orbitals transfer spin information between σ orbitals (spin-transport mechanism) or increase the spin information of a σ orbital by an echo effect. The calculated FC(π) values are rather constant for small polyenes ranging between 3.5-5.5 Hz for a double bond. They decay more slowly with the distance between perturbing and responding nucleus than the σ contributions to the FC term. The sign of the passive FC(π) contribution can be assessed from a Dirac vector model. The limits for longrange coupling in a polyene were determined and their practical implications discussed.",
keywords = "decomposition, spin-spin coupling constants, SSCCs, Fermi contact spin coupling",
author = "J{\"u}rgen Gr{\"a}fenstein and Tell Tuttle and Dieter Cremer",
year = "2005",
month = "2",
day = "7",
doi = "10.1039/b416153j",
language = "English",
volume = "7",
pages = "452--462",
journal = "Physical Chemistry Chemical Physics",
issn = "1463-9076",
number = "3",

}

Analysis of long-range NMR spin-spin coupling in polyenes and the π-mechanism. / Gräfenstein, Jürgen; Tuttle, Tell; Cremer, Dieter.

In: Physical Chemistry Chemical Physics, Vol. 7, No. 3, 07.02.2005, p. 452-462.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Analysis of long-range NMR spin-spin coupling in polyenes and the π-mechanism

AU - Gräfenstein, Jürgen

AU - Tuttle, Tell

AU - Cremer, Dieter

PY - 2005/2/7

Y1 - 2005/2/7

N2 - The J-OC-PSP (decomposition of J into Orbital Contributions using Orbital Currents and Partial Spin Polarization) method is applied to analyze NMR spin-spin coupling constants in polyenes, which were calculated using coupled perturbed density functional theory in connection with the B3LYP hybrid functional and a [7s,6p,2d/4s,2p] basis set. The analysis revealed that the π-mechanism for Fermi contact (FC) spin coupling is based on passive π-orbital contributions. The π-orbitals transfer spin information between σ orbitals (spin-transport mechanism) or increase the spin information of a σ orbital by an echo effect. The calculated FC(π) values are rather constant for small polyenes ranging between 3.5-5.5 Hz for a double bond. They decay more slowly with the distance between perturbing and responding nucleus than the σ contributions to the FC term. The sign of the passive FC(π) contribution can be assessed from a Dirac vector model. The limits for longrange coupling in a polyene were determined and their practical implications discussed.

AB - The J-OC-PSP (decomposition of J into Orbital Contributions using Orbital Currents and Partial Spin Polarization) method is applied to analyze NMR spin-spin coupling constants in polyenes, which were calculated using coupled perturbed density functional theory in connection with the B3LYP hybrid functional and a [7s,6p,2d/4s,2p] basis set. The analysis revealed that the π-mechanism for Fermi contact (FC) spin coupling is based on passive π-orbital contributions. The π-orbitals transfer spin information between σ orbitals (spin-transport mechanism) or increase the spin information of a σ orbital by an echo effect. The calculated FC(π) values are rather constant for small polyenes ranging between 3.5-5.5 Hz for a double bond. They decay more slowly with the distance between perturbing and responding nucleus than the σ contributions to the FC term. The sign of the passive FC(π) contribution can be assessed from a Dirac vector model. The limits for longrange coupling in a polyene were determined and their practical implications discussed.

KW - decomposition

KW - spin-spin coupling constants

KW - SSCCs

KW - Fermi contact spin coupling

UR - http://www.scopus.com/inward/record.url?scp=13844271578&partnerID=8YFLogxK

U2 - 10.1039/b416153j

DO - 10.1039/b416153j

M3 - Article

VL - 7

SP - 452

EP - 462

JO - Physical Chemistry Chemical Physics

T2 - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

SN - 1463-9076

IS - 3

ER -