Volatile trinuclear heterometallic beta-diketonates: Structure and thermal properties related to the chemical vapor deposition of composite thin films

Methoxy-substituted b-diketonates are suitable ligands to create stable and volatile trinuclear heterometallic complexes. Thermal stability during evaporation allows considering new heterocomplexes as promising candidates for MOCVD precursors of multicomponent inorganic films. [Display omitted] •New volatile heterometallic complexes with β-diketonate ligands.•Trinuclear structure of [PbL2{M(hfa)2}2] composition, M = Co or Ni.•Methoxy-substituted ligand L provides thermal stability and volatility.•First study of trinuclear β-diketonate heterometallics as CVD precursors. A series of new trinuclear molecular complexes [PbL12{Co(hfa)2}2] (1), [PbL12{Ni(hfa)2}2] (2), [PbL22{Co(hfa)2}2] (3), [PbL22{Ni(hfa)2}2] (4), [PbL32{Co(hfa)2}2] (5), [PbL32{Ni(hfa)2}2] (6), where L = methoxy-substituted β-diketonate RCOCHCOC(CH3)2OCH3, L1: R = CH3, L2: R = CF3, L3: R = C(CH3)3; hfa = hexafluoroacetylacetonate, were synthesized. Crystal structures were determined by single crystal X-ray analysis. Volatility and thermal stability of the obtained compounds were studied by thermal gravimetric analysis, vacuum sublimation and by mass transfer in helium flow. It was established that all the obtained heterometallic complexes are volatile and can be sublimed in vacuum without dissociation into monometallic complexes. Compounds 3–6 were examined as SSP (single source precursors) in conventional low pressure MOCVD (Metalorganic Chemical Vapor Deposition) of inorganic films on Si(100) substrates. Influence of precursor composition on their structure and thermal properties as well as on the composition of the deposited inorganic films are discussed.