DFT and ab initio direct dynamics study on the reaction of H2 loss reaction from H2BNH2

DFT and ab initio molecular orbital calculations are carried out for the H-2 loss reaction from aminoborane (H2BNH2). The geometries of all the stationary points are optimized at the B3LYP and MP2 methods with a series of basis sets up to aug-cc-pVTZ. The harmonic vibrational frequencies are calculated at the same level of theory. One transition state is found at the B3LYP/(aug-)cc-pVTZ and MP2/(aug-)cc-pVTZ level of theory. The energies and enthalpies are refined at the G3, G3MP2, GWP2B3, CBS-Q, CBS-QB3, and HL methods based on the geometries optimized using B3LYP/aug-cc-pVTZ method. The rate constants are evaluated using the conventional transition-state theory (TST), canonical variational transition-state theory (CVT), and canonical variational transition-state theory with small curvature tunneling correction (CVT/SCT) and conventional transition-state theory with Eckart tunneling correction (TST/Eckart). (c) 2004 Elsevier B.V. All rights reserved.