Nickel(II)-azido/thiocyanato complexes of 1-alkyl-2-(arylazo) imidazole: single crystal X-ray structure of [Ni(Pai-Me)2(N3)2] (Pai-Me=1-methyl-2(phenylazo)imidazole)

Reaction of Ni(ClO₄)₂ · 6H₂O with 1-alkyl-2-(arylazo)imidazole (RaaiR^/) and sodium azide (NaN₃) or ammonium thiocyanate (NH₄SCN) (1 : 2 : 2 molar ratio) in methanol gives [Ni(RaaiR^/)₂(X)₂] (X=N₃ (3, 4) and SCN (5, 6). All these complexes are characterized by elemental analyses, UV–Vis and IR spectral data, thermal and magnetic moment measurements. The X-ray structure is confirmed by single crystal measurement of [Ni(Pai-Me)₂(N₃)₂] (3a). Cyclic voltammetry exhibits quasireversible response at >0.80 V corresponding to Ni(III)/Ni(II) couple along with ligand reductions at negative potential (