Quantum chemical analysis of the orientational lone-pair effect on spin-spin coupling constants

Abstract

The quantum-chemical analysis of factors defining the stereospecific behaviour of nuclear spin-spin coupling constants is shown to be an important aid in obtaining experimental information on molecular structures from high-resolution NMR spectroscopy. The analyses presented in this paper are based on the contributions from localized molecular orbitais within the polarization propagator approach (CLOPPA) method and examples are given where factors defining heteroatom lone-pair orientational effects on spin-spin coupling constants are discussed.