On electronic structure of tris(dimethylamino)sulphonium heptafluoro-oxocyclotetraphosphazenate

The results of 3D periodic B3LYP calculations of tris(dimethylamino)sulphonium heptafluoro-oxocyclotetraphosphazenate in experimental geometry are compared with the analogous results for its isolated anion and cation in experimental and B3LYP optimized geometry. The electronic structure structure is evaluated in the terms of QTAIM topological analysis of electron density. PN bonds alternation and an increased cyclotetraphosphazene ring puckering is not due to solid state effects but due to O/F substitution. Tris(dimethylamino)sulphonium cation in experimental geometry has two SN bonds with positive electron density Laplacians at bond critical points (BCP) whereas the third SN bond has this value negative as expected for covalent bonds. Its B3LYP optimized structure of C3 symmetry has all SN bonds with negative BCP electron density Laplacians.