Reactivity of bis(mu-hydroxo) divanadium site in gamma-H2SiV2W10O40(4-) with hydroxo compounds.
The reactivity of divanadium-substituted silicotungstate, gamma-H2SiV2W10O40(4-) (I), with hydroxo compounds of alcohols, carboxylic acids, and water is reported. The reaction of the bis(mu-hydroxo) divanadium site in I with primary alcohols and formic acid smoothly proceeds to form corresponding monoesters and monoformate, respectively, and the crystal structures of the monomethyl and monoethyl esters and the monoformate of I are determined. The oxygen exchange between the hydroxo group and water proceeds easily. On the other hand, bulky compounds of 2-propanol, tert-butyl alcohol, and acetic acid hardly react with the bis(mu-hydroxo) divanadium site (equilibrium constant < 0.01) because of the steric crowding between the methyl groups and the polyoxometalate framework.
Nakagawa
Yoshinao
Y
Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Uehara
Kazuhiro
K
Mizuno
Noritaka
N
D000438:Alcohols / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry; D017640:Silicates / Q000737:chemistry*; D017973:Tungsten Compounds / Q000737:chemistry*; D014639:Vanadium / Q000737:chemistry*; D014867:Water
D000438:Alcohols; D002264:Carboxylic Acids; D017640:Silicates; D017973:Tungsten Compounds; D014639:Vanadium; D014867:Water; C021746:silicotungstic acid