Single crystals of [Cd(pyrazine)Cl2],[Zn(pyrazine)Cl2] and [Zn(pyrimidine)Cl2] were obtained by a diffusion technique from aqueous solutions of the metal dichlorides and solutions of the respective diazine. The structures consist of “supramolecular” networks of-M-Cl-M - and -M-diazine-M-chains