Density functional theory study of multiprotonated BH5

An extensive density functional theory (DFT) study with ten DFT methods to determine the ionization potentials and electron affinities of BH2, BH3, BH 4 and BH5 was performed. Various ways of the preparation of both BH4 and BH 5 and energy profiles for these reactions in the gas phase were discussed. Further study was directed in determining the stability of the protonated B H5 isomers, their stability and their capability to be prepared by the prot onation of BH5, the H-3(+) molecular association with BH3 and the double hy drogen molecule association with BH2+. New thermodynamic values were propos ed for several ionic reactions that include borane, and the reliability of the hybrid DFT method in comparison with the gradient-corrected and the loc al DFT method for the study of these molecular systems were discussed. (C) 2000 Elsevier Science B.V. All rights reserved.