Noncovalent Chelation by Halogen Bonding in the Design of Metal- Containing Arrays: Assembly of Double ?-Hole Donating Halolium with CuI-Containing O,O-Donors

Five new copper(I) complexes-composed of the paired dibenzohalolium and [CuL2]- (L = 1,2,4-oxadiazolate) counterions in which O,O-atoms of the anion are simultaneously linked to the halogen atom-were generated and isolated as the solid via the three-component reaction between [Cu(MeCN)4](BF4), sodium 1,2,4-oxadiazolates, and dibenzohalolium triflates (or trifluoroacetates). This reaction is different from the previously reported CuI-catalyzed arylation of 1,2,4-oxadiazolones by diaryliodonium salts. Inspection of the solid-state X-ray structures of the complexes revealed the strong three-center X center dot center dot center dot O,O (X = Br, I) halogen bonding occurred between the oxadiazolate moieties and dibenzohalolium cation. According to performed theoretical calculations, this noncovalent interaction (or noncovalent chelation) was recognized as the main force in the stabilization of the copper(I) complexes. An explanation for the different behavior of complexes, which provide either chelate or nonchelate binding, is based on the occurrence of additional -CH3 center dot center dot center dot pi interactions, which were also quantified.

Automated summary

Five new copper(I) complexes were generated and isolated as a solid via a three-component reaction. These complexes consist of dibenzohalolium cation and 1,2,4-oxadiazolate anion, with simultaneous linkage between the O,O atoms of the anion and the halogen atom. The strong three-center halogen bonding between the oxadiazolate moieties and the dibenzohalolium cation was identified as the main force in stabilizing the copper(I) complexes.