Chalcogen atoms are a class of substituents capable of generating inner and outer derivatives of boron clusters. It is well known that chalcogenated boron clusters can form strong σ-hole interactions when a chalcogen atom is a part of an icosahedron. This paper studies σ-hole interactions of dicarbaboranes with two exopolyhedral chalcogen atoms bonded to carbon vertices. Specifically, a computational investigation has been carried out on the co-crystal of (1,2-C2B10H10)2Se4•toluene and a single crystal of (1,2-C2B10H10)2Te4.

• Keywords
• co-crystal, heteroborane, sigma hole,
• MeSH
• Boranes chemistry   MeSH
• Chalcogens chemistry   MeSH
• Crystallization MeSH
• Models, Molecular MeSH
• Static Electricity MeSH
• Thermodynamics MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Boranes MeSH
• Chalcogens MeSH

This paper presents a study of pnictogen bonding in a series of pyrazine•PnX5 (Pn = P, As, Sb and X = F, Cl, Br) complexes. The whole series was studied computationally. Moreover, the pyrazine complexes with PCl5 and SbCl5 were prepared and characterized experimentally. It was found that the Pn-N distances are only slightly elongated when compared to the sum of covalent radii. The conformation of PnX5 changed considerably upon the complex formation, which resulted in a significant change of the dipole moment of the PnX5 fragment and a considerably more positive σ-hole on the pnictogen atom. Finally, interaction energies were decomposed in order to provide a deeper insight into the nature of the studied pnictogen-bonded complexes. Graphical abstract The conformation of PnX5 changed considerably upon the complex formation, which resulted in a considerably more positive σ-hole on the pnictogen atom.

• Keywords
• Charge transfer, Deformation energy, Interaction energy decomposition, Pnictogen bond, X-ray crystallography, σ-hole magnitude,
• Publication type
• Journal Article MeSH