title: Synthesis, structure, and catalytic properties of V(IV), Mn(III), Mo(VI), and U(VI) complexes containing bidentate (N, O) oxazine and oxazoline ligands.
abstract: Synthesis of seven complexes containing oxazoline ([(L(1))(2)V=O] (4), [(L(1))(2)MoO(2)] (5), [(L(1))(2)UO(2)] (6); HL(1) (1) [HL(1) = 2-(4',4'-dimethyl-3'-4'-dihydroxazol-2'-yl)phenol]), chiral oxazoline ([(L(2))(2)UO(2)] (7); HL(2) (2) [HL(2) = (4'R)-2-(4'-ethyl-3'4'-dihyroxazol-2'-yl)phenol]), and oxazine ([(L(3))(2)V=O] (8), [(L(3))(2)Mn(CH(3)COO(-))] (9), [(L(3))(2)Co] (10); HL(3) (3) [HL(3) = 2-(5,6-dihydro-4H-1,3-oxazolinyl)phenol]) and their characterization by various techniques such as UV-vis, IR, and EPR spectroscopy, mass spectrometry, cyclic voltammetry, and elemental analysis are reported. The novel oxazine (3) and complexes 4, 5, 8 and 9 were also characterized by X-ray crystallography. Oxazine 3 crystallizes in the monoclinic system with the P2(1)/n space group, complexes 4 and 9 crystallize in the monoclinic system with the P2(1)/c space group, and complexes 5 and 8 crystallize in the orthorhombic system with the C222(1) space group and the P2(1)2(1)2(1) chiral space group, respectively. The representative synthetic procedure involves the reaction of metal acetate or acetylacetonate derivatives with corresponding ligand in ethanol. Addition of Mn(OAc)(2).4H(2)O to an ethanol solution of 3 gave the unexpected complex Mn(L(3))(2).(CH(3)COO(-)) (9) where the acetate group is coordinated with the metal center in a bidentate fashion. The catalytic activity of complexes 4-9 for oxidation of styrene with tert-butyl hydroperoxide was tested. In all cases, benzaldehyde formed exclusively as the oxidation product.
authors.affiliation: Departments of Chemistry, Indian Institute of Technology, Bombay, Powai, Mumbai 400 076, India.
authors.forename: Karuppasamy
authors.initials: K
authors.lastname: Kandasamy
authors.forename: Harkesh B
authors.initials: HB
authors.lastname: Singh
authors.forename: Ray J
authors.initials: RJ
authors.lastname: Butcher
authors.forename: Jerry P
authors.initials: JP
authors.lastname: Jasinski
mesh_terms: D002384:Catalysis; D018360:Crystallography, X-Ray; D008024:Ligands; D008345:Manganese / Q000737:chemistry; D019216:Metals, Heavy / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D008982:Molybdenum / Q000737:chemistry; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry; D010078:Oxazines / Q000737:chemistry*; D010080:Oxazoles / Q000737:chemistry*; D014501:Uranium / Q000737:chemistry; D014639:Vanadium / Q000737:chemistry
chemical_list: D008024:Ligands; D019216:Metals, Heavy; D009942:Organometallic Compounds; D010078:Oxazines; D010080:Oxazoles; D014639:Vanadium; D008345:Manganese; D014501:Uranium; D008982:Molybdenum