Catalysis of the electroreduction of O-2 to H2O by vanadium-salen complexes in acidified dichloromethane

Citation
E. Tsuchida et al., Catalysis of the electroreduction of O-2 to H2O by vanadium-salen complexes in acidified dichloromethane, INORG CHEM, 38(16), 1999, pp. 3704-3708
Citations number
27
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Inorganic & Nuclear Chemistry
Journal title
INORGANIC CHEMISTRY
ISSN journal
0020-1669 → ACNP
Volume
38
Issue
16
Year of publication
1999
Pages
3704 - 3708
Database
ISI
SICI code
0020-1669(19990809)38:16<3704:COTEOO>2.0.ZU;2-A
Abstract
Addition of stoichiometric quantities of trifluoromethanesulfonic (triflic) acid to solutions of (VO)-O-IV(salen) (H-2-salen = N,N'-ethylenebis(salicy lideneamine)) in dichloromethane produces the mu-oxo dinuclear vanadium(IV) complex [(salen)(VOVIV)-O-IV(salen)](2+) ([(VOVIV)-O-IV](2+)). Addition of significant excesses of triflic acid converts the dimer into [V-IV(salen)] (2+). In dichloromethane solutions containing 0.1 M tetrabutylammonium tetr afluoroborate, the [(VOVIV)-O-IV]2+ complex undergoes disproportionation an d dissociation reactions to produce a solution containing an equimolar mixt ure of (VO)-O-IV(salen), [V-III(salen)](+), and [(VOVV)-O-IV](3+). The oxop hilic [V-III(salen)](+) complex reacts with O-2 to accomplish a four-electr on reduction of O-2: 2[V-III(salen)](+) + O-2 --> 2[(VO)-O-V(salen)](+). Th ese reactions can be exploited to carry out catalytic electroreductions of O-2 to H2O in acidified dichloromethane solutions of (VO)-O-IV(salen) at un usually positive potentials.