Chalcogen bonds formed through p- holes: SO. complexes with nitrogen and phosphorus bases

The possibility of formation of chalcogen bonds through -holes is examined by means of ab initio calculations at MP2/aug-cc-pVTZ level. We investigate the complexes of SO3 with a series of electron-donating nitrogen bases (ZN), including NH3, H2CNH, NH2F, NP, NCH, NCF, NF3, and N-2, and their phosphorous analogues (ZP). The ZN:SO3 complexes show shorter chalcogen bond distances than the ZP:SO3 counterparts, accompanied with the more negative interaction energy in the former than in the latter. To understand the nature of interactions, molecular electrostatic potential analysis is performed. In addition, the quantum theory of atoms in molecules and electron localisation function are employed to analyse the chalcogen bond properties in these complexes. [GRAPHICS]