New polyoxomolybdenum coordination compounds: Synthesis and characterization of mixed-valent Mo6O13(Hsal)2(sal)2(acac)2 and homovalent Mo4O10(acac)4 (Hsal-Â =Â 2-HO-C6H4CO2-, sal2-Â =Â 2-O-C6H4CO22-)

Two new polynuclear oxo compounds of molybdenum have been synthesized: mixed-valence (MoV/MoVI) Mo6O13(Hsal)2(sal)2(acac)2 and homovalent Mo4O10(acac)4 from the reaction of MoO2(acac)2 and salicylic acid in toluene. XPS studies confirmed that the Mo6 complex contains both MoV and MoVI in spite of the diamagnetic nature of the complex.