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

Cocrystallization of the dimeric [Cu 2 (μ-I) 2 (CNXyl) 4 ] (Xyl = 2,6-Me 2 C 6 H 3 , 1 ) and polymeric catena -[Cu(μ-I)(CNC 6 H 3 -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 [ 1 ·I 2 ]·[Cu(μ 1,1 -I 3 )(CNXyl) 2 ] 2 followed by the generation of [Cu(μ 1,3 -I 3 )(CNXyl) 2 ] 2 ·2I 2 ( 5 ·2I 2 ) or [Cu(μ 1,1 -I 3 )(CNC 6 H 3 -2-Cl-6-Me) 2 ] 2 and then [Cu(μ 1,3 -I 3 )(CNC 6 H 3 -2-Cl-6-Me) 2 ] n · n / 2 I 2 . The polyiodide 5 ·2I 2 exhibits a novel supramolecular motif─a purely inorganic halogen-bonded Cu 2 (μ 1,3 -I 3 ) 2 core in the chair conformation. The X-ray structure of 5 ·2I 2 featuring I···I 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 5 ·2I 2 .