DFT-DVM study on the Bi-capped Keggin type heteropoly anions [PM12O40(VO)2]n- (M = Mo, n=5; M = V, n=9)

The electronic structures of the bi-capped Keggin type heteropoly anions [PM12O40(VO)(2)](n-) (M = Mo, n = 5; M = V, a = 9) have been calculated by the density functional theory coupled with the discrete variational method (DFT-DVM). The influences of the formation of the two caps on the electronic structure and the catalytic properties of the heteropoly anions were discussed, compared with the reported results of the Keggin type heteropoly anions (PM12O40)(n-) (M = Mo, n = 3; M = V, n = 15). The calculated results show that the formation of the two cam exerts significant influences on the electronic structure of the Keggin type heteropoly anions. which may lead to major differences between these two clusters in participating in catalytic reactions.