metal-organic compounds
Two polymorphic forms of a mixed zinc/copper biquinoline dihydrogenphosphate are presented, showing almost identical monomeric units, viz. (2,2′-biquinoline-κ2N,N′)bis(dihydrogenphosphato-κO)copper(II)/zinc(II), formulated as [ZnxCu1−x(H2PO4)2(C18H12N2)], with x = 0.88 (1) and 0.90 (2). The cation is tetrahedrally coordinated to a chelating biquinoline system and two diprotonated phosphate anions. The structures differ mainly in their intermolecular hydrogen-bonding interactions, leading to different packing schemes. No significant evidence of stress due to the Zn/Cu solid solution formation was detected.