Some new and recent ferrocene- and ruthenocene-centred reagents for n-type silicon surfaces in photoelectrochemical use

The synthesis and characterisation of trichlorosilylruthenocene (1) and seven ferrocene derivatives, namely bis(1,1′-ferrocenediyl)germane (3), 1,1′-dichloro-2,2′-ferrocenediyldiphenylsilane (4), bis(1,1′-dichloro-2,2′-ferrocenediyl)silane (5), 1,1′-dichloro-2-trichlorosilylferrocene (6), 1-dimethylaminomethyl-2-trichlorosilylferrocene (7), 1,1-dichloro-2,2′dicarboxyferrocene (8), and 1, 1′-dichloro-2,2′-ferrocenediyldichlorosilane (9), are reported. The derivatisation of n-type silicon electrodes using these materials and 1,1′- dicarboxyruthenocene (2), 1,1′-ferrocenediylphenylphosphine (10), bis(1,1′- ferrocenediyl)silane (11), 1,1′-ferrocenediyldiphenylsilane (12), and 1,1′-dicarboxyferrocene (13) was investigated by cyclic voltammetry. The results showed wide variations in electrode behaviour; none of the systems showed a photoreponse which persisted beyond several hundred cycles.