A new inorganic–organic hybrid based on proline functionalized γ-octamolybdate, [Co2(H2O)6(C5H9NO2)2(Mo8O26)]·2H2O (1) has been synthesized under hydrothermal conditions from the reaction of an Evans–Showell-type polyoxometalate (NH4)6[Co2Mo10H4O38], and proline. Characterization by infrared spectroscopy (IR), elemental analysis, diffuse reflectance spectroscopy (DRS) and single crystal X-ray diffraction methods revealed that 1 is a coordination polymer. Compound 1 undergoes a disorder under hydrothermal conditions. This is due to changes in the bond lengths and angles in isopolyanion and proline ligands compared to the non-disordered state. As a result, the molecule loses its symmetry and in the molecular state and in the crystalline phase, a chiral structure is obtained. The structure of proline allows the cobalt ion to not only have a covalent interaction with proline via the carboxyl group of proline, but also to act as a linker between two isoples, leading to a covalent chain. Then, adjacent 1-D chiral chains joined together by another Co-O covalent interactions to yield a 2-D supramolecular chiral layer. The topology of 1, can be rationalized as a two dimensional square lattice (sql) coordination network with point symbol {}2{48.66.8} in which, [Mo8O26(C5H9NO2)2]4− units act as linkers and the Co cations as nodes. Nonetheless, proline ligands have no direct role in expanding the structure as a 2-D covalent polymer. Anti-cancer activity of compound 1 was also evaluated to determine the IC50 values against two human-derived colon cancer and normal fibroblast cells. According to the results compound 1 exhibits both concentration- and time-dependent anti-proliferative effects on the cancerous cells.

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