RPA AM1 calculations of NMR spin-spin coupling constants: geminal119Snsingle bond119Sn couplings

GUSTAVO A. AUCAR; EDITH L. BOTEK; SUSANA B. GOMEZ; EDUARDO SPROVIERO; RUBÉN H. CONTRERAS

JOURNAL OF ORGANOMETALLIC CHEMISTRY

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 1996 vol. 524 p. 1 - 7

0022-328X

In this paper a method for calculation of NMR spin-spin coupling constants is implemented at the random phase approximation (RPA) using the semiempirical AM1 approach with localized molecular orbitals. It is found that for tin-containing molecules the AM1 ground state wave function is near a Hartree-Fock instability of the non-singlet type. A method to circumvent this condition is presented and the resulting approach is applied to study a few structural and substituent effects on geminal 2J(119Sn119Sn) couplings known from the literature. Results thus obtained show several trends which are in fair agreement with those known experimentally.