Matrix isolation infrared study of complexes between and : Evidence of formation of hydrogen bond and chalcogen bond

Abstract

Among the non-covalent interactions, the most well studied is the hydrogen bonding interaction. A new type of non-covalent interaction is the chalcogen bonding interaction. In the present work 1:1 complex of [▪] has been characterised using matrix isolation infrared spectroscopy and electronic structure calculations. Two minima have been obtained on the dimer potential energy surface at the MP2 level of calculations with 6-311++G(d,p) and 6-311++G(3df,2pd) basis sets. One of the minima is stabilised by ▪ hydrogen bond and the other minima is stabilised by ▪ chalcogen bond along with secondary ▪ hydrogen bond. Vibrational spectra in the ▪ stretching, ▪ stretching, and ▪ bending modes have been monitored to understand the complex formation. The formation of the hydrogen- and chalcogen-bonded complex in ▪ and ▪ matrices are confirmed by comparison of the experimental and simulated vibrational frequencies. Stabilisation energy, energy decomposition analysis, natural bond orbital analysis, and atoms in molecules analysis provide insight into the nature of the interactions. This work presents the first experimental report where both the hydrogen- and chalcogen-bonded complexes are formed simultaneously. This work also provides the first impression of the ▪ hydrogen bonding and ▪ chalcogen bonding interaction between ▪ and ▪.