Crystal structure of (2,2'-bipyrid-yl)[2,6-bis-(1-butyl-1 H -benzimidazol-2-yl)pyridine]-chlorido-iridium(III) tri-fluoro-methane-sulfonate.

The title complex compound, [Ir(C ₂₇ H ₂₉ N ₅ )Cl(C ₁₀ H ₈ N ₂ )](CF ₃ SO ₃ ) ₂ , was synthesized for a study of iridium(III)/periodate redox systems in water. The coordination geometry of the complex can be best described as distorted octa-hedral, with an r.m.s. deviation of 8.8 (8)% from ideal octa-hedral rectangular geometry. In the crystal, C-H⋯O and C-H⋯F inter-actions between the complex cation and the tri-fluoro-methane-sulfonate anions are observed, as well as a C-H⋯Cl inter-molecular inter-action between neighboring complex cations. In addition, the benzimidazole ring systems display parallel-displaced π-π stacking with centroid-centroid distances of 3.585 (3)-3.907 (3) Å. One of the two tri-fluoro-methane-sulfonate anions is disordered over two orientations with an occupancy ratio of 0.582 (6):0.418 (6). The title complex was characterized using FT-IR, cyclic voltammetry/rotating disc electrode polarography, fluorescence spectrometry, high resolution mass spectrometry, CHN elemental analysis and ¹ H NMR spectroscopy.