Single crystals of hexaaquacobalt(II) dipotassium tetrahydrogen tetra-o-phthalate tetrahydrate K-2[Co(H2O)(6)](C8HSO4)(4)center dot 4H(2)O (PCHP), a semiorganic light-rose colored crystal of size similar to 38 x 16 x 4 mm(3) have been grown by slow evaporation solution growth technique. The lattice parameters of the as-grown crystals were obtained by single crystal X-ray diffraction analysis. The functional groups of the phthalate complex were confirmed by Fourier transform infrared spectroscopy analysis. The UV-Vis optical absorption spectrum of PCHP shows the lower optical cut-off at similar to 300 nm and the crystal was transparent in the visible region. The structural perfection of the grown crystal has been analyzed by high-resolution X-ray diffraction (HRXRD) rocking curves (DC). The DC contains multi-peaks showing the structural grain boundaries. The dielectric, thermal and mechanical behaviors of the specimen were also studied. (C) 2013 Elsevier B.V. All rights reserved.