Water-Assisted Concerted Proton-Electron Transfer at Co(II)-Aquo Sites in Polyoxotungstates With Photogenerated Ru^III (bpy)₃³⁺ Oxidant.

ABSTRACT: The cobalt substituted polyoxotungstate [Co₆ (H₂ O)₂ (α-B-PW₉ O₃₄ )₂ (PW₆ O₂₆ )]^17- (Co6) displays fast electron transfer (ET) kinetics to photogenerated Ru^III (bpy)₃³⁺ , 4 to 5 orders of magnitude faster than the corresponding ET observed for cobalt oxide nanoparticles. Mechanistic evidence has been acquired indicating that: (i) the one-electron oxidation of Co6 involves Co(II) aquo or Co(II) hydroxo groups (abbreviated as Co6(II)-OH₂ and Co6(II)-OH, respectively, whose speciation in aqueous solution is associated to a pK_a of 7.6), and generates a Co(III)-OH moiety (Co6(III)-OH), as proven by transient absorption spectroscopy; (ii) at pH

SUBMITTER: Rigodanza F 

PROVIDER: S-EPMC8251842 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature