New organic-inorganic rod-like hybrids constructed from Keggin-type polyoxomolybdate and a Cu(ii) dithiocarbamate complex: crystal structure, dye adsorption and antibacterial activity.

Novel rod-like organic-inorganic crystalline hybrid materials, namely {Cu[S2CN(CH2Ph)2]2}[H3PMo12O40], (abbreviated as Cu(diBzDTC)2-H3POMo), were synthesized by reacting copper(ii) chloride, in situ prepared N,N-dibenzyldithiocarbamic acid (HdiBzDTC) and H3PMo12O40 polyoxomolybdate (H3POMo) in methanol. The resulting hybrid material was characterized using various techniques, including single-crystal X-ray diffraction, Fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), UV-vis spectroscopy, scanning electron microscopy (SEM) with an energy-dispersive X-ray (EDX) analyzer, transmission electron microscopy (TEM), thermogravimetry and differential thermal (TG/DTA) analyses, elemental analysis, and zeta potential measurements. SEM and TEM images validated the presence of a highly porous rod-like structure in the hybrid sample. Single-crystal X-ray diffraction analysis disclosed that the crystal structure of the hybrid is composed of a single H3POMo building block alongside a Cu(diBzDTC)2 unit. These units were connected through electrostatic and van der Waals interactions to form a three-dimensional supramolecular framework. H3POMo clusters fill in the cages and holes constructed by the Cu(diBzDTC)2 molecules. The presence of H3POMo building blocks in the hybrid structure made it highly efficient and selective in adsorbing cationic organic pollutants, with a removal efficiency of 96% for methylene blue within 40 min, even when mixed with other substances. The hybrid can be easily separated and reused without any alteration in its structure. Additionally, the hybrid displayed significant antibacterial activity against Gram-negative and Gram-positive bacteria, including A. aureus, S. epidermidis, B. cereus, E. coli, and K. pneumoniae., with inhibition zone diameters of 13-21 mm, as determined by the disk diffusion method. To the best of our knowledge, the Cu(diBzDTC)2-H3POMo represents the first example of a hybrid based on POMs and dithiocarbamate complexes.