New heterometallic copper zinc alkoxides: synthesis, structure properties and pyrolysis to Cu/ZnO composites

The copper compound [(THF)KCu(OtBu)3]∞1 was obtained by interaction of a 1:1 mixture of ZnCl2/CuCl2 with KOtBu. Bi- and trifunctional aminoalcohols were used to synthesize the intramolecularly donor stabilized Cu(II) alkoxides Cu(OCH(R)CH2NMe2)2 (3: R=Me, 4: =CH2NMe2) where 4 was structurally characterized. Lewis acid–base adduct formation with (Me3Si)3CZnCl gave the heterodinuclear compounds (Me3Si)3CZnCl · Cu(OCH(R)CH2NMe2)2 (5: R=Me, 6: R=CH2NMe2), which were characterized by X-ray single-crystal structure analysis. The two metal centers Cu and Zn of 5 and 6 are bridged by two oxygen atoms to form a Cu–O–Zn core. Pyrolysis of compounds 5 and 6 in dry argon or a H2/N2 mixture at atmospheric pressure forms metallic copper and zinc oxide, whereas pyrolysis under O2/Ar forms additionally oxidized copper species. Elemental analysis of the pyrolysis products showed carbon and nitrogen contamination. Scanning electron microscopy and energy dispersive X-ray analysis were performed to get information on the morphology and the chemical composition of the pyrolysis products.