Photo-Assisted Synthesis of Inorganic Polyoxovanadate

Photosynthesis plays a vital role on the earth and photo-induced organic reactions have artificially created many valuable materials. However, the photo-induced syntheses of inorganic compounds are much less reported. Herein, we reported the photo-assisted synthesis of a mixed-valence polyoxovanadate with the formula [C9H14N]6[V15O36Cl] under AM1.5 irradiation in N2 atmosphere. Single-crystal X-ray diffraction analysis reveals a hexagonal structure (space group P63/mmc) with cell parameters a = 14.1100(6) A, b = 14.1100(6) A, c = 22.0265(10) A, and V = 3797.8(4) A3. UV-Vis and EPR analyses verified the [V15O36Cl]6- cluster formed within 0.5 h; powder XRD results indicated that crystalline phase appeared for irradiation of 9.5 h (200 mW/cm2). These findings suggested the nucleation and crystallization processes took longer time than [V15O36Cl]6- cluster formation and dominated the [C9H14N]6[V15O36Cl] crystal formation. This primary work could open the door for the syntheses of inorganic compounds using photo-assisted reactions instead of conventionally thermo-driving syntheses.