Abstract
The title complex, (C(8)H(20)N)[Co(CN)(4)(C(10)H(8)N(2))]·CH(3)CN·1.5H(2)O, consists of tetra-ethyl ammonium cations, mononuclear [Co(III)bpy(CN)(4)](-) anions and uncoordinated water and acetonitrile mol-ecules. The Co(III) atom is six-coordinated by two 2,2'-bipyridine (bpy) N atoms and four cyanide C atoms in a distorted octa-hedral geometry. The acute bite angle of the chelating bpy [82.28 (8)°] is the main factor accounting for this distortion. In addition, the tetra-ethyl-ammonium cation is significantly disordered [occupancy ratio 0.611 (3):0.389 (3)]. The presence of water mol-ecules, one of which is disordered over two positions about an inversion center, results in the formation of a network of O-H⋯N hydrogen bonds involving the cyanide N atoms.