Cobalt(II)-azoimidazole complexes: Structures of [Co(MeaaiMe)4](ClO4)2 · H2O and [Co(HaaiMe)2(NCS)2] (MeaaiMe = 1-methyl-2-(p-tolylazo)imidazole; HaaiMe = 1-methyl-2-(phenylazo)imidazole)

1-Alkyl-2-(arylazo)imidazole (RaaiR′) coordinates through imidazole-N to Co(II) in a tetrahedral orientation to synthesise [Co(RaaiR′)4](ClO4)2 · H2O. The reaction of N3-orSCN- with [Co(RaaiR′)4](ClO4)2 · H2O has synthesized Co(RaaiR′)2(X)2(X=N3-,SCN-). Representative complexes are characterized by single-crystal X-ray diffraction studies.