Quantum-chemical study of donor-acceptor interactions between silicon, phosphorus, and sulfur halides and ammonia

Abstract

1. Donor-acceptor interactions between silicon, phosphorus, and sulfur halides and the nitrogen atom in the ammonia molecule were studied theoretically by applying the LCAO-MO method in the MNDO approximation. 2. According to the calculation, an approximation of a supermolecule with a complete optimization of geometry shows that the strength of the donor-acceptor bond in complexes with NH3 decreases in the series PCl3 > SiF4 > SiCl4 > SCl2 > PF3 > SF2, while heat of the formation and charge transfer are higher in complexes of silicon, phosphorus, and sulfur halides with ammonia molecules than in the corresponding complexes with formaldehyde.