名称:
Syntheses, structures, fluorescent properties and natural bond orbital analyses of metal–organic complexes based on 5,6-substituted 1,10-phenanthroline derivatives
摘要:
Six new metal-organic coordination complexes, [Cd(MEDPQ)(2,5-pydc)](n) (1), [Cd-2(MOPIP)(2)(2,5-pydc)(2)](n) (2), [Cu-2(MOPIP)(2)(2,5-pydc)(2)]center dot H2O (3), [Mn(MOPIP)(2)(2,5-pydc)]center dot 3H(2)O (4), [Cd(MOPIP)(2)(2,6-pydc)]center dot 3H(2)O (5) and [Cd-2(MOPIP)(2)(2,3-pydc)(2)center dot H2O](n) (6) (MEDPQ = 2-methyldipyrido[3,2-f:2',3'-h]quinoxaline, MOPIP = 2-(4-methoxyphenyl)-1H-imidazo[4,5-f][1,10]phenanthroline, 2,5-H(2)pydc = pyridine-2,5-dicarboxylic acid, 2,6-H(2)pydc = pyridine-2,6-dicarboxylic acid, and 2,3-H(2)pydc = pyridine-2,3-dicarboxylic acid), have been prepared through hydrothermal reactions. The transformation of coordination modes of transition metal ions and organic carboxylate ligands has a crucial influence on the multinuclear structures of these series. In compounds 1 and 2, binuclear Cd(II) subunits occur, which are connected by 2,5-pydc anions to construct an undulating network. By selecting the different transition metal, ions, we get the compounds 3 and 4. For the compound 3, the Cu(II) centers are linked by 2,5-pydc ligands to form a binuclear dimer. Compound 4 shows a mononuclear compound. For complexes 5 and 6, by changing the dicarboxylate ligands, Cd(II) adopts a heptacoordinated mode to form a mononuclear compound and chain framework. In addition, fluorescent properties of 2-4 have been reported. (c) 2013 Elsevier Ltd. All rights reserved.