Lead(II) complex with methoxy-substituted beta-diketonate − structure, thermal behavior and unexpected thermolysis byproduct

Abstract

New complex of lead(II) with beta-diketonate ligand PbL2 is described, where L=CH3COCHCOC(OCH3)(CH3)2, 5-methoxy-5-methylhexan-2,4-dionate). Crystal structure of the compound has been determined and its thermal properties have been studied. Chains of 1D coordination polymers form crystals of the complex, where the molecules are connected through the chelate-bridging oxygen atoms, methoxy groups remain free and form hydrogen bonds between the chains. PbL2 sublimates at 120 °C under reduced pressure (P=10−2 Torr) with partial decomposition. When heated in the condensed phase the complex decomposes with the formation of lead(II) oxide and evolution of a pyran derivative into gas phase. The mechanism of lead(II) complex thermolysis in support of the condensation of two ligands is discussed. A new organic product was identified by 13C and 1H NMR, IR and PL spectroscopy and mass spectrometry; the crystal structure of the product was determined.