Role of hydrogen peroxide in the synthesis of nitrogen heterocycle containing cobalt complexes

The reactions of Co(O2CCH3)(2)center dot 4H(2)O with the sodium salt of p-toluene sulfonic acid (NapTS) and pyridine (py) or 4-methylpyridine (4mepy) in the presence of hydrogen peroxide in methanol led to the formation of [Co(py)(3)(H2O)(3)](pTS)(2) or [Co(4mepy)(2)(H2O)(4)](pTS)(2)center dot MeOH. respectively. The coordination polymer [(Co(44'bpy)(H2O)(4))(pTS)(2)](n) (4,4'-bipyridine = 44'bpy) was obtained from the reaction of Co(O2CCH3)(2)center dot 4H(2)O with 44'bpy 44'bpy in the presence of NapTS. The reaction of Co(O2CCH3)(2)center dot 4H(2)O, 2,2'-bipyridine (22'bpy) and NapTS with hydrogen peroxide resulted in the formation of the dinuclear complex [Co-2(mu-OH)(2)(mu-O2CCH3)(O2CCH3)(2)(22'bpy)(2)](pTS). characterization of these complexes and the role of hydrogen peroxide in these reactions are discussed. Similar reactions with sodium sulfamate gave the mononuclear [Co(22'bpy)(2)(O2CCH3)]NH2SO3 center dot 2H(2)O complex and [Co-2(mu-OH)(2)(mu-O2CCH3)(O2CCH3)(2) (22'bpy)(2)](NH2SO3). (C) 2011 Elsevier Ltd. All rights reserved.