ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Thermodynamics of Cation—Base Complexes L---M, Where M = H⁺, Li⁺ and L is H₂0, HF, NH₃, PH₃ , SiH₂, and CO

M. Remko

Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Comenius University, SK-832 32 Bratislava

Abstract: Ab initio molecular orbital calculations at the G1, G2, and CBS levels of theory have been performed for complexes of water, hydrogen fluoride, ammonia, carbon monoxide, phosphane, hydrogen sulfide, and silylene in order to determine the effects of molecular structure on gas-phase basicity towards H⁺ and Li⁺. It is shown that basicities towards metal cation Li⁺ differ considerably from the corresponding gas-phase basicities towards Hf. Calculated interaction enthalpies vary as ∆H_H+ >> ∆H_Li+. The relative basicities of the bases studied depend characteristically on the type of cation and coordination site. The GI, G2, CBS-Q, and CBS-APNO methods reproduce the known experimental gas-phase interaction energies of the complexes studied with a comparable accuracy.

Full paper in Portable Document Format: 525a637.pdf

Chemical Papers 52 (5) 637–642 (1998)