Synthesis and characterization of fluoride-incorporated polyoxovanadates

Abstract

The speciation studies of oxovanadates are essential to clarify their biological activities. We surveyed the distribution of oxovanadate species in the presence of halide anions with various acid concentrations in an aqueous mixed-solvent system. The presence of chloride, bromide, and iodide anions has no effects on the appearance of polyoxovanadate species observed in 51 V NMR. Those are precedented formation of metavanadate species and decavanadates. The presence of fluoride anion during the addition of acids exhibits the strong intervention in the polyoxovanadate equilibria and we found the subsequent formation of two polyoxovanadate species by 51 V NMR observation.

Synthesis and oxidation catalysis of a difluoride-incorporated polyoxovanadate and isolation of active vanadium alkylperoxo species

“…42 On the other hand, the chemistry of fluoride-incorporated polyoxovanadates is noteworthy. 34,[43][44][45][46][47][48][49][50][51][52][53] While usual polyoxovanadates with anion templates possess single anions surrounded by only square pyramids, most fluorideincorporated polyoxovanadates possess two fluoride inside the spheres. Furthermore, some of these fluorideincorporated polyoxovandates adopt coordination environments of tetrahedra, trigonal by-pyramids in addition to square pyramids (Table S2 †).…”

“…1). 44 Compound V11 can be considered as a dimer of V7 species. In a mixed solution of acetonitrile and water in the presence of fluoride, the addition of acid to [V 4 O 12 ] 4− , which is one of the simplest precursors, successively provides V7 and V11.…”

Synthesis and structural characterization of tube-type tetradecavanadates

“…Polyoxovanadates often construct cage-type molecules in a reduced form with a mixed valence state (Mü ller et al, 1998). The condensation of V V polyoxovanadates or the oxidation of those reduced polyoxovanadates produces V V polyoxovanadates such as [ (Kikukawa et al, 2015;Kobayashi et al, 2014). Among the series of polyoxovanadates, [V 12 O 32 ] 4À has a unique bowl-type structure that can accommodate various guest anions in the cavity, for example, it encapsulates not only halides but also molecular anions such as CN À , OCN À , NO 2 À , NO 3 À , HCO 2 À and CH 3 CO 2 À (Kuwajima et al, 2017a,b).…”

Structure Transformation among Deca-, Dodeca- and Tridecavanadates and Their Properties for Thioanisole Oxidation

“…The employment of non-aqueous solvent increases the diversity of the polyoxovanadates. Up to now, various isopolyoxovanadates with only fully oxidized V 5+ , such as [V3O9] 3 [6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Since the properties such as redox and optics of polyoxovanadates depend on the anion structures, it is crucially important to control those cluster frameworks [14,19].…”