Tetrabromoethane as σ-Hole Donor toward Bromide Ligands: Halogen Bonding between C2H2Br4 and Bromide Dialkylcyanamide Platinum(II) Complexes

The complexes trans-[PtBr2(NCNR2)2] (R2 = Me21, (CH2)52) were cocrystallized with 1,1,2,2-tetrabromoethane (tbe) in CH2Cl2 forming solvates 1·tbe and 2·tbe, respectively. In both solvates, tbe involved halogen bonding, viz. the C–Br···Br–Pt interactions, detected by single-crystal X-ray diffractions experiments. Appropriate density functional theory calculations (M06/def2-TZVP) performed for isolated molecules complex-tbe clusters, where existence of interactions their noncovalent nature confirmed electrostatic potential surfaces (ρ 0.001 a.u.) molecules, topology analysis electron density, localization function HOMO-LUMO overlap projections clusters.