Cadmium nitrate coordination polymers with substituted pyridazino[4,5-d]pyridazines.

catena-Poly[[aquabis(nitrato-kappa2O,O')cadmium(II)]-mu-1,2,3,6,7,8-hexahydrocinnolino[5,4,3-cde]cinnoline-kappaN1:kappaN6], [Cd(NO3)2(C12H12N4)(H2O)]n, (I), and catena-poly[[[bis(nitrato-kappa2O,O')cadmium(II)]-mu-2,2,7,7-tetramethyl-1,2,3,6,7,8-hexahydrocinnolino[5,4,3-cde]cinnoline-kappaN1:kappaN6] chloroform solvate], {[Cd(NO2)2(C12H12N4)].CHCl3}n, (II), are the first structurally examined cadmium-pyridazine coordination compounds. They possess one-dimensional polymeric structures supported by the bidentate bridging function of the cinnolino[5,4,3-cde]cinnoline ligands, which lie about inversion centres. The Cd atoms are seven-coordinated in (I) and six-coordinated in (II), involving two bidentate nitrate groups [Cd-O = 2.229 (2)-2.657 (2) A], two N atoms of the cinnoline ligands [Cd-N = 2.252 (2)-2.425 (2) A], and, additionally, a water O atom in (I) [Cd-O = 2.284 (2) A]. In (I), the coordinated organic and aqua ligands form an intramolecular O-H...N hydrogen bond [O...N = 2.730 (3) A].