The mixed-ligand species Zn[(R12PO2)2 – 2x(R22PO2)2x](R1= Bun; R2= n-C6H13 or n-C10H21) are linear coordination copolymers with a random distribution of two different bridging phosphinate groups along the molecular chains. Single crystals of the copolymer {Zn[Bun2PO2(n-C6H13)2PO2]}n are disordered. A three-dimensional X-ray analysis has been attempted. The crystals contain chains characterised by a backbone structure with alternate single and triple bridging phosphinate groups between tetrahedral metal atoms. The structural features common to those of the β-form of zinc(II) di-n-butylphosphinate polymer are discussed.