Triiodide-Based Chair-Like Copper Complex Assembled by Halogen Bonding

Cocrystallization of the dimeric [Cu-2(mu-I)(2)(CNXyl)(4)] (Xyl = 2,6-Me2C6H3, 1) and polymeric catena-[Cu(mu-I)(CNC6H3-2-Cl-6-Me)(2)] (2) complexes with I-2 at different molar ratios between the reactants resulted in a series of (RNC)(2)CuI-based crystal polyiodides formed along with gradual accumulation of iodine, namely the cocrystals [1I-2][Cu(mu(1,1)-I-3)(CNXyl)(2)](2) followed by the generation of [Cu(mu(1,3)-I-3)(CNXyl)(2)](2)2I(2) (52I(2)) or [Cu(mu(1,1)-I-3)(CNC6H3-2-Cl-6-Me)(2)](2) and then [Cu(mu(1,3)-I-3)(CNC6H3-2-Cl-6-Me)(2)](n)(n)/I-2(2). The polyiodide 52I(2) exhibits a novel supramolecular motif & horbar;a purely inorganic halogen-bonded Cu-2(mu(1,3)-I-3)(2) core in the chair conformation. The X-ray structure of 52I(2) featuring II contacts was analyzed by a set of theoretical methods and attributed to moderately strong halogen bonding (from -3.2 to -3.9 kcal/mol); these interactions determine the supramolecular architecture of 52I(2).