The N.M.R. spectra of the A3*A3*X2and the A4X2systems

Abstract

The matrix elements of the nuclear spin Hamiltonian are tabulated for these two systems. The A₃*A₃*X₂ system considered is one with a centre or plane of symmetry, whilst the A₄X₂ system has molecular symmetry C _2v , C _2h or D _2h , with no magnetically equivalent nuclei. The frequencies which can be written explicitly in terms of the coupling constants are given, and the determination of relative signs of coupling constants is discussed.