A novel mixed ligand Zn-coordination polymer: Synthesis, crystal structure, thermogravimetric analysis and photoluminescent properties

A novel mixed ligand based coordination network of Zn, having formula [Zn-8(Or)(8)(dpp)(4)(H2O)(8)](n) (1), have been engineered and synthesized at room temperature by self-assembly of potassium orotate (OrK) and 1,3 di(4-pyridyl)propane (dpp) with metal salt, Zn(OAc)(2)center dot 2H(2)O Single crystal X-ray structural analysis reveals that coordination sphere around Zn(II) ions, in Or-Zn-dpp moiety, having different atomic arrangement with distorted square pyramidal geometry. The syn-anti mu(2)eta(1):eta(1) bridging carboxylate and pyridyl moieties extended the Or-Zndpp skeleton into 2D coordination network showing square grid sheet. The emission spectrum of Zn-complex was recorded with 290 nm excitation wavelength which reflects that 1 has strong luminescence with peak maximum of 380 nm (3.2627 eV) and is a result of the n-pi* and pi-pi* transitions of H(3)Or and dpp ligand. Thermogravimetric analysis shows that when the coordinated water molecule completely comes out from the complex around 320 degrees C, the dehydrated forms steadily starts to degrade, and the complete decomposition is observed above 350 degrees C.