Zinc-orotate coordination polymer: synthesis, thermogravimetric analysis and luminescence properties

Abstract

Orotic acid formulated coordination network of formula [Zn(HOr)·3H 2 O] n (1) prepared by reactions of orotic acid potassium salt [K(H 2 Or)] accompanied by metal salts Zn(OAc) 2 ·2H 2 O at room temperature. X-ray single-crystal investigation confirms that the carbonyl oxygen of the ring in 1 is structure factor for 1D Zn-orotate coordination chain. The hydrogen bonding among uncoordinated carboxylate oxygen of ligand and one of the aqua ligand assembles the nearby parallelly stacked 1D coordination chain into 2D hydrogen bonded architecture, further hydrogen bonding among coordinated water and carbonyl oxygen incorporating O-H···O synthons yielding into 3D hydrogen bonded coordination network. O-H···O synthons were the only concoction for hydrogen bonded metal-organic network of zinc coordination polymers. The emission spectra of Zn-orotate complex shows excitation wavelength at 270 nm which depicts that 1 has strengthened photoluminescence with peak recorded of 376 nm (3.2975 eV) and is the outcomes of n-π* and π-π* transitions of orotate ligand. Thermal decomposition predicts that at 120 °C, lattice water molecule entirely release out from the complex, moderately degradation starts and around 370 °C the entire disintegration has been inspected.

Zinc Oxide Nanocomposites—Extracellular Synthesis, Physicochemical Characterization and Antibacterial Potential

“…The initial weight loss at 129.72 °C, with the weight loss rate at 0.1859%/°C, is related to the removal of residual water. The second and third stages are similar to each other (200.33 °C and 224.7 °C, respectively) and appeared due to the elimination of coordinated water molecules [ 70 , 71 ]. The biggest change in the weight loss was observed from 217.74 °C (85.86% of weight) to the 396.19 °C (66.24% of weight)—it might be assigned to the decomposition step, including the removal of the organic deposit of nanocomposites and ending with the formation of ZnO [ 70 , 71 , 72 ].…”