Analysis of the Electronic Origin of the (1)J(CH) Spin-Spin Coupling Trend in 1-X-Cyclopropanes: Experimental and DFT Study

Autor(es)

Neto, Alvaro Cunha ^[1] ; dos Santos, Francisco P. ^[1] ; Contreras, Ruben H. ^{[2, 3]} ; Rittner, Roberto ^[1] ; Tormena, Claudio F. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Chem, Dept Organ Chem, BR-13084971 Sao Paulo - Brazil

^[2] Consejo Nacl Invest Cient & Tecn, Buenos Aires, DF - Argentina

^[3] Univ Buenos Aires, Fac Ciencias Exactas & Nat, Dept Phys, Buenos Aires, DF - Argentina

• Tipo de documento: Artigo Científico
• Fonte: Journal of Physical Chemistry A; v. 112, n. 46, p. 11956-11959, NOV 20 2008.
• Citações Web of Science: 13

Resumo

A conceptual analysis of the CLOPPA (Contributions from Localized Orbitals within the Polarization Propagator Approach) expressions that deconvolute NMR spin-spin coupling constants {[}Diz A. C.; Giribet C. G.; Ruiz de Azua, M. C.; Contreras, R. H. Int. J. Quantum Chem. 1990, 37, 663.] into orbital contributions can provide an in-depth insight into the features of the electronic molecular structure that originate a given (1)J(CH) experimental trend. In this work, several 1-X-cyclopropane derivatives are taken as model compounds to apply such ideas to rationalize substituent effects on the Fermi contact term Of (1)J(CLH) spin-spin coupling. It is shown that in this type of coupling, its experimental trend, as measured in this work, cannot be accounted for with only the ``bond{''} and the ``other bond{''} contributions, requiring the inclusion of ``other antibonding contributions{''}. Such effect is discussed in terms of hyperconjugative interactions. (AU)

• Processo FAPESP: 05/59649-0 - Estudos de estrutura eletrônica e molecular através de métodos espectroscópicos e cálculos teóricos
• Beneficiário: Roberto Rittner Neto
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 06/03980-2 - Interacoes de orbitais e seus efeitos nas constantes de acoplamento escalar em rmn: estudo experimental e teorico.
• Beneficiário: Claudio Francisco Tormena
• Modalidade de apoio: Auxílio à Pesquisa - Regular