Keggin-type" organically modified oxopolymetalates of formula [R]4[SiW11O40(SiR')2], (R=Bu4N+, R' = -C2H5, -C10H21, -CH=CH2, -CH2CH=CH2, -OH, -C6H5, -C10H7, -C6H4NH2 (o, p), -C6H4NMe2 (p), -C6H4CH=CH2, -C6H4CF3, -C6H4CH=CHC6H5) were synthesized. The oxide core presented reversible redox properties which were tuned by the choice of the organic modifier. Parallel variations of the 183W NMR chemical shifts were measured and both effects might be related to the electronic donor-acceptor properties of the organic radical. The magnitudes of these effects are compared with those coming from the electrolyte itself.
organically modified oxopolymetalates; redox properties; 183W NMR spectroscopy
