A novel imidazole-functionalized dioxovanadium complex [V2O2(C2O4)(aIM)(4)] (aIM = 1-allylimidazole) was synthesized by the reaction of VO(acac)(2) with 1-allylimidazole and fully characterized by single-crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR) and elemental analyses. Interestingly, the oxalate was in-situ generated from the acetylacetone anion of VO(acac)(2) and further coordinated with the vanadium cation and finally complex 1 was achieved. The crystal of complex 1 belongs to the monoclinic system, space group P2(1)/n with a = 10.7922(9), b = 10.6296(8), c = 13.2936(11) angstrom, mu = 0.677 mm(-1), M-r = 686.48, V = 1516.9(2) angstrom(3), Z = 2, D-c = 1.503 g/cm(3), F(000) = 708, R = 0.0543, and wR = 0.1517 for 2459 observed reflections with I > 2 sigma(I). Notably, complex 1 is further used as catalyst in the oxidation of sulfides using H2O2 as the oxidant and exhibits excellent catalytic performance (conv. up to 95.6%, sele. up to 98.9%).