Unexpected Geometrical Effects on Paramagnetic Spin-Orbit and Spin-Dipolar (2)J(FF) Couplings

Autor(es)

Ducati, Lucas C. ^[1] ; Contreras, Ruben H. ^{[2, 3]} ; Tormena, Claudio F. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Chem, BR-13084971 Campinas, SP - Brazil

^[2] Univ Buenos Aires, Dept Phys, FCEyN, Buenos Aires, DF - Argentina

^[3] IFIBA CONICET, Buenos Aires, DF - Argentina

• Tipo de documento: Artigo Científico
• Fonte: Journal of Physical Chemistry A; v. 116, n. 20, p. 4930-4933, MAY 24 2012.
• Citações Web of Science: 9

Resumo

The second-rank tensor character of the paramagnetic spin orbit and spin dipolar contributions to nuclear spin spin coupling constants is usually ignored when NMR measurements are carried out in the isotropic phase. However, in this study it is shown that isotropic (2)J(FF) couplings strongly depend on the relative orientation of the C F bonds containing the coupling nuclei and the eigenvectors of such tensors. Predictions about such effect are obtained using a qualitative approach based on the polarization propagator formalism at the RPA, and results are corroborated performing high-level ab initio spin spin coupling calculations at the SOPPA(CCSD)/EPR-III//MP2/EPR-III level in a model system. It is highlighted that no calculations at the RPA level were carried out in this work. The quite promising results reported in this paper suggest that similar properties are expected to hold for the second-rank nuclear magnetic shielding tensor. (AU)

• Processo FAPESP: 10/10993-9 - Estudo do mecanismo de transmissão de constantes de acoplamento escalar através do espaço
• Beneficiário: Claudio Francisco Tormena
• Modalidade de apoio: Auxílio à Pesquisa - Regular