In this work, we report the synthesis and X-ray characterization of diphenylphosphinic acid (L) (redetermination at 100 K), and its two polymeric phosphinate complexes; [(C6H5)(2)P(O)OSn(C6H5)(3)](n) (C1) and [Cu(O2PPh2)(2)](n) (C2), resulted from the bidentate coordinatioan of L. Sn(IV) centers in C1 are five-coordinate in a distorted trigonal bipyramidal geometry. One dimensional coordination chains of C2 are made by double-bridging ligands between the copper atoms, surrounded with four P-O in a square planar polyhedron. Structural characterization of the complexes revealed that M - O bonds are responsible for the assembly of the primary structural motifs in both the complexes while C-H center dot center dot center dot pi and H center dot center dot center dot H interactions are effective in organizing these molecules into extended 3D architectures. The quantitative mapping of interactions was also analyzed using Hirshfeld surface analysis. With respect to the (PNMR)-P-31 spectra, there are probably fast transformations in the solution and different types of coordinated and dissociated species are in balance, consistent with the optimized structures in the solvent and gas phases. (C) 2019 Elsevier B.V. All rights reserved.