A Computational Study of Chalcogen-containing H 2 X…YF and (CH 3 ) 2 X…YF (X=O, S, Se; Y=F, Cl, H) and Pnicogen-containing H 3 X'…YF and (CH 3 ) 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.