Transition-Metal Complexes of Pyrrole Pigments. 18. Redox Behaviors of Oxomolybdenum(V) Complexes Formed with Macrocyclic Tetrapyrroles

Yoshihisa Matsuda, Sunao Yamada, Yukito Murakami

    Research output: Contribution to journalArticlepeer-review

    35 Citations (Scopus)

    Abstract

    The redox chemistry of (2,3,17,18-tetramethyl-7,8,12,13-tetraethylcorrolato)oxomolybdenum(V) [Mo(0)(MEC)] and (5,10,15,20-tetraphenylporphinato)oxomolybdenum(V) complexes [Mo(0)(TPP)(X), X = MeO, AcO, and Cl] was investigated in dichloromethane by means of cyclic voltammetry and controlled-potential electrolysis. One-electron oxidation and reduction of Mo(0)(MEC) at Mov were observed at +0.70 and -0.72 V vs. SCE, respectively. Such oxidation and reduction potentials for Mo(0)(TPP)(X) were very dependent on the nature of axial ligand X and consequently on the covalent character of the Mov-X bond: one-electron reduction becomes less facile as the covalent character increases and reaches the value of that in Mo(0)(MEC) for X = MeO. The TPP complexes were much more resistant to oxidation of Mov than the MEC complex. Two successive reductions of TPP were observed for Mo(0)(TPP)(X) at -1.1 and -1.5 V vs. SCE while no ligand reduction was detected for Mo(0)(MEC) in the cathodic region up to -2.0 V vs. SCE. On the basis of complete redox schemes for Mo(0)(MEC) and Mo(0)(TPP)(X), correlations between redox properties and ligand structures have been discussed. Coordination equilibria for reactions of Mo(0)(TPP)(MeO) with AcO”, Cl”, and C104” were investigated in dichloromethane, and the chloro complex was found to exist as a dimer while the others are monomers in solution.

    Original languageEnglish
    Pages (from-to)2239-2246
    Number of pages8
    JournalInorganic Chemistry
    Volume20
    Issue number7
    DOIs
    Publication statusPublished - Jan 1 1981

    All Science Journal Classification (ASJC) codes

    • Physical and Theoretical Chemistry
    • Inorganic Chemistry

    Fingerprint

    Dive into the research topics of 'Transition-Metal Complexes of Pyrrole Pigments. 18. Redox Behaviors of Oxomolybdenum(V) Complexes Formed with Macrocyclic Tetrapyrroles'. Together they form a unique fingerprint.

    Cite this