Synthesis,characterization and crystal structure of a new unsymmetric tetranuclear copper-carbonate complex:reversible CO_2 fixation

摘要

A novel tetranuclear unsymmetric copper(II) complex [Cu_4~(II)(TPPNOL)_2(CO_3)_2](ClO_4)_2 centre dot 6H_2O (1),(HTPPNOL=N,N,N'-tris-(2-pyridylmethyl)-1,3-diaminopropan-2-ol),was obtained by the reaction between copper(II) perchlorate hexahydrate and the ligand HTPPNOL,under a CO_2 atmosphere,in a basic medium.The synthesis,X-ray crystal structure and spectroscopic properties of (1) are presented.The reversibility of the CO_2 fixation process was monitored by UV-Vis spectroscopy in an aqueous medium (NaOH/HClO_4), and a nucleophilic CO_2 fixation mechanism through the intermediate hydroxo [Cu_2(HTPPNOL)(OH)_2]~+ complex is proposed.