The mutual influence of Y center dot center dot center dot N and H center dot center dot center dot H interactions in XHY center dot center dot center dot NCH center dot center dot center dot HM complexes (X = F, Cl, Br; Y = S, Se; M = Li, Na, BeH, MgH): tuning of the chalcogen bond by dihydrogen bond interaction

摘要

The equilibrium structures, interaction energies, and bonding properties of ternary XHY center dot center dot center dot NCH center dot center dot center dot HM complexes are studied by ab initio calculations, where X = F, Cl, Br, Y = S, Se, and M = Li, Na, BeH, MgH. The ab initio calculations are carried out at the MP2/aug-cc-pVTZ level. The results indicate that all optimized Y center dot center dot center dot N and H center dot center dot center dot H binding distances in the ternary complexes are smaller than the corresponding values in the binary systems. The calculated cooperative energies (E-coop) are between -0.20 kcal/mol in BrHS center dot center dot center dot NCH center dot center dot center dot HBeH and -3.29 kcal/mol in FHSe center dot center dot center dot NCH center dot center dot center dot HNa. For a given Y and M, the estimated E-coop values increase as X = F > Cl > Br. In addition, the selenium-bonded complexes exibit larger E-coop values than those of the sulfur-bonded counterparts. The cooperativity between Y center dot center dot center dot N and H center dot center dot center dot H interactions is further analyzed by quantum theory of atoms in molecules and natural bond orbital methods. Cooperative effects make an increase in the J(Y-N) and J(H-H) spin-spin coupling constants of the ternary complexes with respect to the binary systems.