Synthesis, characterization and study of the chromogenic properties of the hybrid polyoxometalates [PW11O39(SiR)2O]3-(R = Et, (CH2)nCH=CH2 (n = 0, 1, 4), CH2CH2SiEt3, CH2CH2SiMe2Ph)

Reaction of Cl3SiR or (EtO)(3)SiR with [PW11O39](7-) affords the disubstituted hybrid anions [PW11O39(SiR)(2)O](3-). These species have been characterized by IR spectroscopy in the solid state and by multinuclear NMR (H-1, Si-29, P-31 and W-183) and cyclic voltammetry in solution. The hydrosilylation of [PW11O39(Si-CH=CH2)(2)O](3-) has been achieved with Et3SiH and PhSiMe2H. These are the first examples of hydrosilylation on a hybrid tungstophosphate core. The chromogenic behaviour of hybrid species has been demonstrated in solution. (c) 2006 Elsevier B.V. All rights reserved.