NMR of HBF4

Longitudinal and transverse relaxation times for all three species of nuclei in aqueous solutions of HBF4 have been measured by pulse techniques. Relaxation measurements were performed at room temperature as a function of HBF4 concentration. The relaxation times of each nuclear species exhibited a strong concentration dependence. In addition, cw measurements were performed in order to determine the nature of the electric and magnetic interactions. The results demonstrate that the 19F nuclei are participating in a chemical exchange process which produces a 11B spin multiplet collapse. The concentration dependence of the 1H nucleus was studied to determine the type of coupling that exists between the 1H nuclei and their environment. On the basis of the transverse relaxation and cw measurements, a spin–lattice relaxation model was constructed for the HBF4 system. Theoretical estimates of the relaxation parameters were made using the BPP model.