Structures and stabilities of higher coordinate onium-boronium dications (X+BH3+ and X+BH5+; X = NH3, PH3, H2O, and H2S)

摘要

Structures of higher coordinate onium-boronium dications (X+BH3+ 1–4a and X+BH5+ 1–4d; X = NH3, PH3, H2O, and H2S) were calculated by using the ab initio method at the MP2/6-311+G** level. All of the dications 1–4a contain a four-coordinate boron atom with a three-center two-electron bond involving boron and two hydrogens. On the other hand, all the dications 1–4d contain a six-coordinate boron atom with two three-center two-electron bonds. The thermodynamics of the complexations of 1–4a and H2 to form 1–4d were computed. Deprotonations of 1–4d were found to be substantially endothermic.