title: Methylene bridge regulated geometrical preferences of ligands in cobalt(III) coordination chemistry and phenoxazinone synthase mimicking activity.
abstract: Two new azide bound cobalt(III) complexes, [Co(L(1))(N3)3] (fac-1) and [Co(L(2))(N3)3] (mer-2), where L(1) is bis(2-pyridylmethyl)amine and L(2) is (2-pyridylmethyl)(2-pyridylethyl)amine, derived from tridentate reduced Schiff-base ligands have been reported. Interestingly, a methylene bridge regulated preferential coordination mode of ligands is noticed in their crystal structures: it is found in a facial arrangement in fac-1 and has a meridional disposition in mer-2. Both complexes show phenoxazinone synthase-like activity and the role of the structural factor on the catalytic activity is also explored. Moreover, the easily reducible cobalt(III) center in mer-2 favors the oxidation of o-aminophenol. The ESI-MS positive spectra together with UV-vis spectroscopy clearly suggest the formation of a catalyst-substrate adduct by substitution of the coordinated azide ions in the catalytic cycle.
authors: Postgraduate Department of Chemistry, Panskura Banamali College, Panskura RS, Purba Medinipur, West Bengal 721 152, India. ampanja@yahoo.co.in.
authors: Anangamohan
authors: A
authors: Panja
authors: Milan
authors: M
authors: Shyamal
authors: Amrita
authors: A
authors: Saha
authors: Tarun Kanti
authors: TK
authors: Mandal
mesh_terms: D000627:Aminophenols / Q000737:chemistry; D001386:Azides / Q000737:chemistry; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D056831:Coordination Complexes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008024:Ligands; D010088:Oxidoreductases / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D000627:Aminophenols; D001386:Azides; D056831:Coordination Complexes; D008024:Ligands; C027667:2-aminophenol; D003035:Cobalt; D010088:Oxidoreductases; C023944:2-aminophenol oxidase