Synthesis, characterization and study of the chromogenic properties of the hybrid polyoxometalates [PW11O39(SiR)2O]3− (R = Et, (CH2)nCHdouble bond; length as m-dashCH2 (n = 0, 1, 4), CH2CH2SiEt3, CH2CH2SiMe2Ph)

Reaction of Cl3SiR or (EtO)3SiR with [PW11O39]7− affords the disubstituted hybrid anions [PW11O39(SiR)2O]3−. These species have been characterized by IR spectroscopy in the solid state and by multinuclear NMR (1H, 29Si, 31P and 183W) and cyclic voltammetry in solution. The hydrosilylation of [PW11O39(Si–CHdouble bond; length as m-dashCH2)2O]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.