ab initio study of the electronic structures and heats of formation of some adducts of boron trifluoride

Abstract

The heats of formation in the gas phase of the known and unknown complexes BF₃· NH₃, BF₃· H₂O, BF^–₄, BF₃OH^–, BF₃· CO, BF₃· Cl^–, BF₃· H₂S, BF₃· Ne and BF₃· Ar have been calculated ab initio, using extended basis sets of gaussian-type orbitals. The results reflect correctly the trends in the experimental data where these are available, although fully quantitative results were not obtained. The unknown complexes all have negative heats of formation (i.e., –ΔH_f) and in these cases, complex formation is not favoured by the entropy changes. The charge distributions and bonding throughout the molecules are consistent with the calculated thermodynamics.