Density functional studies on the reagents Me3AsX2 (where X=F, Cl, Br and I) in the gas phase and in solution

A Computational Study of Chalcogen-containing H2 X…YF and (CH3 )2 X…YF (X=O, S, Se; Y=F, Cl, H) and Pnicogen-containing H3 X'…YF and (CH3 )3 X'…YF (X'=N, P, As) Complexes

A computational study was undertaken for the model complexes H₂ X…YF and (CH₃ )₂ X…YF (X=O, S, Se; Y=F, Cl, H), and H₃ X'…YF and (CH₃ )₃ X'…YF (X'=N, P, As), at the MP2/6-311++G(d,p) level of theory. For H₂ X…YF and H₃ X'…YF, noncovalent interactions dominate the binding in order of increasing YF dipole moment, except for H₃ As…F₂ , and possibly H₃ As…ClF. However, for the methyl-substituted complexes (CH₃ )₂ X…YF and (CH₃ )₃ X'…YF the binding is especially strong for the complexes containing F₂ , implying significant chemical bonding between the interacting molecules. The relative stability of these complexes can be rationalized by the difference in the electronegativity of the X or X' and Y atoms.