628291-80-5Relevant articles and documents
First Row Divalent Transition Metal Complexes of Aryl-Appended Tris((pyridyl)methyl)amine Ligands: Syntheses, Structures, Electrochemistry, and Hydroxamate Binding Properties
Makowska-Grzyska, Magdalena M.,Szajna, Ewa,Shipley, Crystal,Arif, Atta M.,Mitchell, Michael H.,Halfen, Jason A.,Berreau, Lisa M.
, p. 7472 - 7488 (2008/10/08)
Divalent manganese, cobalt, nickel, and zinc complexes of 6-Ph 2TPA (N,N-bis((6-phenyl-2-pyridyl)methyl)-N-((2-pyridyl)methyl) amine; [(6-Ph2TPA)Mn(CH3OH)3](ClO 4)2 (1), [(6-Ph2TPA)Co(CH 3CN)](ClO4)2 (2), [(6-Ph 2TPA)Ni(CH3-CN)(CH3OH)](ClO4) 2 (3), [(6-Ph2TPA)Zn(CH3CN)](ClO 4)2 (4)) and 6-(Me2Ph)2TPA (N,N-bis((6-(3,5-dimethyl)phenyl-2-pyridyl)methyl)-N-((2-pyridyl)methyl)amine; [(6- (Me2Ph)2TPA)Ni(CH3CN) 2](ClO4)2 (5) and [(6-(Me2Ph) 2TPA)-Zn(CH3CN)](ClO4)2 (6)) have been prepared and characterized. X-ray crystallographic characterization of 1A·CH3OH and 1B·2CH3OH (differing solvates of 1), 2-2CH3CN, 3·CH3OH, 4·2CH 3CN, and 6·2.5CH3CN revealed mononuclear cations with one to three coordinated solvent molecules. In 1A·CH3OH and 1B·2CH3OH, one phenyl-substituted pyridyl arm is not coordinated and forms a secondary hydrogen-bonding interaction with a manganese bound methanol molecule. In 2·2CH3CN, 3·CH 3OH, 4·2CH3CN, and 6·2.5CH3CN, all pyridyl donors of the 6-Ph2TPA and 6-(Me2Ph) 2TPA ligands are coordinated to the divalent metal center. In the cobalt, nickel, and zinc derivatives, CH/π interactions are found between a bound acetonitrile molecule and the aryl appendages of the 6-Ph2TPA and 6-(Me2Ph)2TPA ligands. 1H NMR spectra of 4 and 6 in CD3NO2 solution indicate the presence of CH/π interactions, as an upfield-shifted methyl resonance for a bound acetonitrile molecule is present. Examination of the cyclic voltammetry of 1-3 and 5 revealed no oxidative (M(II)/M(III)) couples. Admixture of equimolar amounts of 6-Ph2-TPA, M(ClO4)2·6H2O, and Me4NOH·5H2O, followed by the addition of an equimolar amount of acetohydroxamic acid, yielded the acetohydroxamate complexes [((6-Ph2TPA)Mn)2 (μ-ONHC(O)CH 3)2](ClO4)2 (8), [(6-Ph 2TPA)Co-(ONHC(O)CH3)](ClO4)2 (9), [(6-Ph2TPA)Ni(ONHC(O)CH3)](ClO4)2 (10), and [(6-Ph2TPA)Zn(ONHC(O)CH3)](ClO4) 2 (11), all of which were characterized by X-ray crystallography. The Mn(II) complex 8-0.75CH3CN·0.75Et2O exhibits a dinuclear structure with bridging hydroxamate ligands, whereas the Co(II), Ni(II), and Zn(II) derivatives all exhibit mononuclear six-coordinate structures with a chelating hydroxamate ligand.
