5,6-Dioxo-1,10-phenanthrolin-1-ium chloride.

The title compound, C(12)H(7)N(2)O(2) (+)·Cl(-), is isostructural with its bromide analogue. The compound exhibits a layered structure in which all atoms lie on a crystallographic mirror plane. N(+)-H⋯Cl(-) hydrogen bonds, C-H⋯O and C-H⋯Cl(-) contacts are formed within each layer.

catena-Poly[[bis-(N,N'-dimethyl-formamide)cadmium(II)]-μ(2)-oxalato].

The title compound, [Cd(C(2)O(4))(C(3)H(7)NO)(2)](n), is isostructural with its Mn(II) analogue. The structure comprises zigzag polymeric chains with the oxalate groups situated on inversion centres and the Cd(II) atoms located on twofold rotation axes. The coordination geometry around Cd(II) is distorted octa-hedral and the intra-chain Cd⋯Cd distance is 5.