Cobalt(III) Complexes of the 10-Membered Macrocycle 1,4,7-Triazacyclodecane. The Structure of trans-Bis(1,4,7-triazacyclodecane)cobalt(III) Perchlorate

Abstract

The crystal structure of trans-[Co( tacd )₂](ClO₄)₃ has been determined by X-ray diffraction methods and refined to a residual of 0.054 for 2477 independent observed reflections. The crystals are monoclinic, P 2₁/c, a 18.627(2), b 9.3438(5), c 16.057(2)Ǻ, β 119.45(2)°. Two complex cations are located at centres of symmetry and the ligands adopt λ,δ,chair conformations. Bond lengths from cobalt to nitrogen atoms in the six- membered ring (average 1.995 Ǻ) are significantly longer than those only associated with five- membered rings (average 1.961 Ǻ).