Three Pd-decavanadates with a controllable molar ratio of Pd to decavanadate and their heterogeneous aerobic oxidation of benzylic C–H bonds

Abstract

By the combination of Pd-complexes and [V₁₀O₂₈]⁶⁻, three Pd-decavanadate compounds [Pd(NH₃)₄]₃[V₁₀O₂₈]·8H₂O (1), [Pd(deta)(H₂O)]₂(NH₄)₂[V₁₀O₂₈]·2H₂O (2) (deta = diethylenetriamine) and [Pd(dpa)₂](Hdpa)₂(Et₃NH)₂[V₁₀O₂₈]·2H₂O (3) (dpa = 2,2′-dipyridylamine) have been successfully synthesized and thoroughly characterized using single X-ray diffraction (SXRD), powder X-ray diffraction (PXRD), infrared spectroscopy (FT-IR) and elemental analyses (EA). Interestingly, in the three compounds, the molar ratios of Pd to decavanadate vary from 3 : 1 to 1 : 1 by changing N-ligands. The three Pd-decavanadates as heterogeneous catalysts are active in the aerobic oxidation of benzylic hydrocarbons under solvent-free conditions without adding any additives and co-catalysts. Moreover, compound 1 can be reused three times without losing its activity.