Phosphorus-31, selenium-77, and mercury-199 nuclear magnetic resonance studies of bis(tributylphosphine selenide)mercury(II) complexes
Abstract
Fourier-transform 31P, 77Se, and 199Hg n.m.r. spectra and heteronuclear multiple-resonance experiments involving these nuclei have been used to determine the signs and magnitudes of 1J(199Hg–77Se), 1J(77Se–31P), and 2J(199Hg–31P) in HgX2(PBu3Se)2(X = Cl, Br, I, or SCN) at –100 °C. The first coupling constant is negative and relatively small (–751 Hz for X = Cl), and the trends in it and the other coupling constants are interpreted in terms of changes in the hybridisation of the mercury atom and the electronegativity of the HgX2 fragment.