Halogen and chalcogen bonding in dichloromethane solvate of cyclometalated iridium(III) isocyanide complex

Solvent-rich dichloromethane solvate of cis-[Ir(bptz)(2)(CNXyl)(2)] BF4 (3, bptz is cyclometallated 4-(4-bromophenyl)-2-methylthiazole) is prepared via the reaction of chloro-bridged dimer [Ir(bptz)(2) (mu-Cl)](2) (1) with 2,6-dimethylphenyl isocyanide (CNXyl, 2) and AgBF4. Single crystal X-ray diffraction on the 3.31/4CH(2)Cl(2) solvate showed the presence of numerous non-covalent interactions, including the C-S center dot center dot center dot F-B chalogen bonding (ChB), the C-Br center dot center dot center dot Br-C, C-Cl center dot center dot center dot Br-C, and C-Cl center dot center dot center dot S(C)-C halogen bonding (XB), and the C-H center dot center dot center dot F-B hydrogen bonding (HB). The nature of these short contacts was explored both experimentally by single-crystal X-ray diffraction and theoretically by DFT calculations on the empirical geometries followed by Bader's topological electron density distribution analysis. The evaluated energies of XBs and ChBs are in range 1.3-2.2 kcal/mol indicating the non-covalent nature of the contacts.