Synthesis of a metal-dicarboxylate hybrid with three dimensional Na-O-Cu connectivity: Structure, magnetic property and controlled solid state thermolysis leading to CuO nanorod.

Abstract

A one-pot reaction of CuCl2 . 2H2O and malonic acid leads to a novel three dimensional inorganic-organic hybrid framework, [Na2Cu(mal)2(H2O)2]n, (1) (mal = malonate dianion). Single crystal X-ray structure of 1 reveals that it is a novel heterometallic three dimensional coordination-polymeric network which consists of interlocked anionic Cu-malonate and cationic Na-water-malonate sheets, where malonate dianion functions as an unprecedented heptadentate ligand. Low temperature magnetic study reveals that the compound is weak ferromagnetically coupled and this is supported by magneto-structural correlation. Thermogravimetric analyses are performed and it is observed that complex 1 upon heating finally transforms to CuO, which is evident by X-ray powder diffraction technique. Controlled solid state thermolysis of complex 1 at ∼850 °C for 24 h leads to the formation of CuO nanorods, which is confirmed by scanning electron microscopy and X-ray powder diffraction technique. The nanorods formed here have average diameters of ca. 40-200 nm and lengths up to 13 μm.