Electronic properties, redox behavior, and interactions with H2O2 of pH-sensitive hydroxyphenyl-1,2,4-triazole-based oxovanadium(V) complexes.
The syntheses and spectroscopic characterization of two 1,2,4-triazole-based oxovanadium(V) complexes are reported: 1- [VO2L1]- and 2 [(VOL2)2(OMe)2] (where H2L1 = 3-(2'-hydroxyphenyl)-5-(pyridin-2' '-yl)-1H-1,2,4-triazole, H3L2 = bis-3,5-(2'-hydroxyphenyl)-1H-1,2,4-triazole). The ligand environment (N,N,O vs O,N,O) is found to have a profound influence on the properties and reactivity of the complexes formed. The presence of the triazolato ligand allows for pH tuning of the spectroscopic and electrochemical properties, as well as the interaction and stability of the complexes in the presence of hydrogen peroxide. The vanadium(IV) oxidation states were generated electrochemically and characterized by UV-vis and EPR spectroscopies. For 2, under acidic conditions, rapid exchange of the methoxide ligands with solvent [in particular, in the vanadium(IV) redox state] was observed.
Department of Organic and Molecular Inorganic Chemistry, Stratingh Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
Wesley R
WR
Browne
Alette G J
AG
Ligtenbarg
Johannes W
JW
de Boer
Tieme A
TA
van den Berg
Martin
M
Lutz
Anthony L
AL
Spek
Frantisek
F
Hartl
Ronald
R
Hage
Ben L
BL
Feringa
D018360:Crystallography, X-Ray; D004563:Electrochemistry; D004578:Electron Spin Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods; D004583:Electrons; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010084:Oxidation-Reduction; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000295:instrumentation / Q000379:methods; D013237:Stereoisomerism; D014230:Triazoles / Q000737:chemistry*; D014638:Vanadates / Q000737:chemistry*
D008024:Ligands; D009942:Organometallic Compounds; D014230:Triazoles; C045575:1,2,4-triazole; D014638:Vanadates; D006861:Hydrogen Peroxide