Halogen bonds enhanced by σ-hole and π-hole interactions: a comparative study on cooperativity and competition effects between X∙∙∙N and S∙∙∙N interactions in H3N∙∙∙XCN∙∙∙SF2 and H 3N∙∙∙XCN∙∙∙SO2 complexes (X = F, Cl, Br and I).

Halogen bonding, a noncovalent interaction between a halogen atom X in one molecule and a negative site in another, plays an important role in fields as diverse as molecular biology, drug design, and crystal engineering. In this work, the H3N∙∙∙XCN∙∙∙SF2 and H3N∙∙∙XCN∙∙∙SO2 (X  =  F, Cl, Br, I) complexes are theoretically investigated to find ways to enhance the halogen bond interaction. Cooperative effects are found when X∙∙∙N and S∙∙∙N bonds coexist in the same complex.

Theoretical study of the complementarity in halogen-bonded complexes involving nitrogen and halogen as negative sites.

This article analyzes the interplay between X···N and X···X halogen bonds interactions in NCX···NCX···XCH3 complexes, where X=Cl and Br. To better understand the properties of these systems, the corresponding dyads were also studied. These effects are studied theoretically in terms of geometric and energetic features of the complexes, which are computed by ab initio methods.

Characterization of halogen···halogen interactions in crystalline dihalomethane compounds (CH2Cl2, CH2Br2 and CH2I2): a theoretical study.

A theoretical study was performed to examine halogen···halogen (X···X) bonds properties in crystalline dihalomethane CH2X2 compounds (X=Cl, Br and I). MP2/aug-cc-pVTZ calculations reveal that the interaction energies for CH2X2 dimers lie in the range between -3.7 and -9.