NMR Relaxation Time Simulation for Different Models of Motion in (CH3)3NBH3

Monte Carlo simulations of complex rotation of single −CH3 groups, −(CH3)3 groups and −BH3 groups were performed for trimethylamine borane (CH3)3NBH3. In the course of these simulations the correlation functions for different models of rotation were determined. Knowledge of these functions and of some data extracted from NMR experiments allowed for the calculation of the longitudinal magnetic relaxation time T1 as a function of temperature. The values of relaxation times obtained from Monte Carlo simulations are compared to experimental results published by other authors. There is a clear relation between the assumed model of rotation and the shape of the T1 curve versus temperature.