title: Unexpected formation of a novel pyridinium-containing catecholate ligand and its manganese(III) complex.
abstract: Nucleophilic aromatic substitution of tetrachloro-o-benzoquinone by pyridine and reduction of the o-quinone to the catechol by hydroxylamine forms 1,2-dihydroxy-3,5,6-trichlorobenzene-4-pyridinium chloride. This compound reacts with manganese(II) acetate in air to form chlorobis(3,5,6-trichlorobenzene 4-pyridinium catecholate)manganese(III), which represents the first complex of this ligand class to be structurally characterized by X-ray diffraction; this complex is active in the catalytic reduction of dioxygen to hydrogen peroxide under ambient conditions and turnover frequencies (TOFs) >10,000 h(-1) can be obtained.
authors.affiliation: Queen Mary University of London, The Joseph Priestley Building, School of Biological and Chemical Sciences, Mile End Road, London, UK E1 4NS. t.s.sheriff@qmul.ac.uk
authors.forename: Tippu S
authors.initials: TS
authors.lastname: Sheriff
authors.forename: Michael
authors.initials: M
authors.lastname: Watkinson
authors.forename: Majid
authors.initials: M
authors.lastname: Motevalli
authors.forename: Jocelyne F
authors.initials: JF
authors.lastname: Lesin