An ab initio study on the concerted interaction between chalcogen and pnicogen bonds.

We analyzed cooperation between chalcogen-bonding and pnicogen-bonding interactions in XHS···NCH2P···NCY (X = F, Cl; Y = H, OH, NH2, CN and NC) complexes at the MP2/6-311++G** level. These effects were studied in terms of geometric and energetic properties, harmonic frequencies, and nuclear magnetic resonance (NMR). A cooperativity factor was adopted to measure the cooperativity between the two types of interaction in triads based on S-X and P-CN stretching frequencies.