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

Abstract

Orotic acid formulated coordination network of formula [Zn(HOr).3H sub(2) O] sub(n) (1) prepared by reactions of orotic acid potassium salt [K(H sub(2) Or)] accompanied by metal salts Zn(OAc) sub(2) .2H sub(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-Pi* and Pi-Pi* transitions of orotate ligand. Thermal decomposition predicts that at 120 degrees C, lattice water molecule entirely release out from the complex, moderately degradation starts and around 370 degrees C the entire disintegration has been inspected.