The formation of a luminescent Mn(III,IV) intermediate of bis(2-pyridylmethyl)amine and acetone assistant its intramolecular C-H oxidation.

Abstract The dinuclear Mn(II) complexes of bis(2-pyridylmethyl)amine (dpa) reacted with H 2 O 2 producing a fluorescent dioxodimanganese(III,IV) intermediate [(dpa)Mn 2 Cl 2 (μ-O 2 )(OHdpa)] 3+ , which was characterized by IR, UV, ESR, ES-MS and fluorescence spectra. ES-MS data show that this intermediate could bind an acetone molecule forming dioxodimanganese(III,IV)–acetone adduct [(dpa)Mn 2 Cl 2 (μ-O)(CH 3 COCH 3 )(OHdpa)] 3+ . The emission of dioxodimanganese(III,IV)–acetone at 378 nm was stronger than that of dioxodimanganese(III,IV) complex. Excess acetone molecules promoted the intramolecular C–H oxidation and the formation of one dimensional chain Mn(II) complex [(2-picolinic-acid)Mn(H 2 O) 2 Cl(O)] n through possible intramolecular oxygen transfer reaction.