MULTINUCLEAR NUCLEAR-MAGNETIC-RESONANCE, STUDIES OF LEAD(II) SOAPS .3. STUDIES ON THE LIQUID-PHASE WITH REFERENCE TO THE BEHAVIOR OF THE CORRESPONDING ACIDS

H-1 NMR spectra and longitudinal relaxation times have been measured f or a number of even-chain-length lead(II) carboxylates and their corre sponding acids in the liquid phase. Differences are observed, suggesti ng that aggregation occurs in the former case. Support for this comes from the greater spectral linewidths and shorter T1 values observed in the molten carboxylates. From analysis of longitudinal and transverse proton-relaxation rates, estimates are made of aggregate correlation times. From studies of the Pb-207 NMR longitudinal relaxation of molte n lead(ii) decanoate at various field strengths it is suggested that t he dominant relaxation mechanism involves chemical shift anisotropy. U sing this data, information on aggregate motion and size is also obtai ned. C-13 NMR spectra and relaxation data have been studied for the le ad(II) alkanoates and corresponding acids in the liquid phase and the results support the idea of the existence of aggregates. Studies of th e longitudinal C-13 relaxation of molten lead(II) octanoate at various magnetic field strengths provide further insight on these systems, an d support the view that the liquid phase of the molten carboxylates co nsists of small aggregates.