Lewis Acidity of Boron Trihalide: With Density Functional Theory Study

Density functional theoretical calculations on BX3(X = F, Cl, Br) have been carried out at LDA/NL levels in order to interpret the experimental Lewis acidity scale for these molecules studied. An alternative calculation method for chemical hardness, based on the Janak's extension of density-functional theory for fractional occupancies, is employed in the study of the Lewis acidity of boron trihalide. It is shown that the acidity of boron trihalide can be understood in term of the hardness. The molecular hardness calculated from the valence orbital hardness is found to be the best characteristic for the Lewis acidity of boron trihalide.EI0711962