Dynamic nuclear magnetic resonance studies of complexes of 1,2-bis (benzylthio)ethane with chromium, molybdenum, and tungsten carbonyl complexes

Abstract

Band-shape fitting studies have been made for the n.m.r. spectra of the benzylic methylene protons of the complexes [M(CO)₄(bbse)][where M = Cr, Mo, or W; (bbse)= 1,2-bis(benzylthio)ethane]. These studies show that the coalescence phenomenon observed in the temperature-dependent n.m.r. spectra results not from reversal of the chelate rinq but from inversion of configuration about the ligand sulphur atoms. Thermodynamic activation parameters for this latter process are reported: