A new cadmium complex [Cd(C5H5N)CH2C(OH)(PO3)(PO3H)·3H2O]n ((C5H4N)CH2C(OH)(PO3H2)2=1-hydroxy-2-(2-pyridyl)ethylidene-1,1-diphosphonate acid) has been synthesized under hydrothermal conditions. Single crystal structure determination reveals that the compound has a ladder-like chain structure in which the edge- shared {CdO6} octahedra are linked by {CPO3} tetrahedra through corner-sharing. The chains of {Cd(C5H5N)CH2C (OH)(PO3)(PO3H)}n are linked by inter-chain hydrogen bonds, forming a supramolecular layer.
