Metal β-diketonates have received much attention because of their use as MOCVD precursors for oxide materials. Due to their chelating character, β-diketones are not generally considered as proper ligands for the formation of heterometallic species. At the same time, a number of homometallic β-diketonates are known to maintain polynuclear structures in the absence of solvent donor molecules through strong Lewis acid-base interactions or through the formation of oxo(hydroxo)-bridges that strengthen the connections between metal atoms. The focus of our investigation was to develop a simple, high-yield synthetic approach to heterometallic main group – transition metal β-diketonates and oxo-diketonates using the same construction principles as for polynuclear homometallic diketonates. We suggested several low-temperature solid-state synthetic routes that appear to be general for the preparation of heterometallic diketonates incorporating a wide range of s-, p-, d-, and f-metals. Using this investigative approach, the first two families of bimetallic homoleptic diketonates, Bi₂M(β-dik)₈ and PbM(β-dik)₄, that contain heavy main group and the first row divalent transition metals, M = Mn, Fe, Co, Ni, Cu, and Zn, have been obtained. The heterometallic molecules that are held together by strong Lewis acid-base interactions have been shown to remain intact in the gas phase as well as in solutions of non-coordinating solvents.