Structural characterization of a mixed-ligand complex of copper(II) with 1,10-phenanthroline and the m-aminobenzoate ion (original) (raw)
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Journal of …, 2011
The triphenyltin(IV) complexes of 4-[((E)-1-{2-hydroxy-5-[(E)-2-(2-carboxyphenyl)-1-diazenyl]phenyl}methylidene)amino]aryls (aryls = 4-CH 3 , 4-Br, 4-Cl, 4-OCH 3 ) have been synthesized and characterized by 1 H-, 13 C-, 119 Sn-NMR, ESI mass spectrometry, IR and 119m Sn Mö ssbauer spectroscopic techniques in combination with elemental analysis. The crystal structures of a representative carboxylate ligand (aryl = 4-CH 3 ) and three Sn complexes, viz., polymeric (Ph 3 Sn[O 2 CC 6 H 4 {N@N(C 6 H 3 -4-OH(C(H)@ NC 6 H 4 X-4))}-o]) n (X = Me (1) and Br (2)) and dimeric (Ph 3 Sn[O 2 CC 6 H 4 {N@N(C 6 H 3 -4-OH(C(H)@NC 6 H 4 X-4))}-o]) 2 (X = OMe (4)) complexes are reported. The coordination environment in each complex is trigonal bipyramidal trans-Ph 3 SnO 2 . A single zwitterionic carboxylate ligand bridges adjacent Sn atoms via the carboxylate and phenoxide O atoms.
Mixed-Ligand Complexes of Copper(II) with α-Hydroxycarboxylic Acids and 1,10-Phenanthroline
Zeitschrift für anorganische und allgemeine Chemie, 2001
Eight new two-ligand complexes of copper(II) with 1,10-phenanthroline and one of four different a-hydroxycarboxylic acids (glycolic, lactic, mandelic and benzylic) were prepared. The complexes of general formula [Cu(HL) 2 -(phen)]´nH 2 O (HL = monodeprotonated acid) (1±4) were characterized by elemental analysis, IR, electronic and EPR spectroscopy, magnetic measurements and thermo-gravimetric analysis. The complexes of general formulae [Cu(HL)(phen) 2 ](HL)´H 2 L´nSolv [1 a (HL = HGLYO ± , n = 1, Solv = MeCN) and 3 a (HL = HMANO ± , n = 0)] and [Cu(L)(phen)(OH 2 )]´nH 2 O [2 a (L = LACO 2± , n = 4) and 4 a (L = BENO 2± , n = 2)] were characterized by X-ray diffractometry. In all these latter a pentacoordinated copper atom has a basically square pyramidal coordination polyhedron, the distortion of which towards a trigonal bipyramidal configuration has been evaluated in terms of the parameter s. In 1 a and 3 a there are three forms of a-hydroxycarboxylic acid: a monodentate monoanion, a monoanionic counterion, and a neutral molecule lying in the outer coordination sphere; in 2 a and 4 a the a-hydroxycarboxylic acid is a bidentate dianion coordinating through carboxyl and hydroxyl oxygens. Parameter s definiert. In 1 a und 3 a liegen die a-Hydroxycarbonsa È ure in drei Formen vor: als einza È hniges Monoanion, als monoanionisches Gegenion und als neutrales Moleku È l in der a È uûeren Koordinationsspha È re; in 2 a und 4 a ist die a-Hydroxycarbonlsa È ure ein zweiza È hniges Dianion, das u È ber die Carboxyl-und Hydroxyl-Sauerstoffatome koordiniert.
Inorganic Chemistry, 1993
The synthesis of the novel nitrogen ligand 2,9-bis(N-pyrazolylmethyl)-l ,lO-phen (bpmp), C Z O H~~N~, and of the tetrafluoroborate and perchlorate salts of its copper(1) and copper(I1) complexes, respectively, are reported. The structures of the free ligand and of the copper(I1) complex have been determined by three-dimensional X-ray diffraction methods. The ligand crystallizes in the space group P21 of the monoclinic system with two molecules in a cell of dimensions a = 5.979(2) A, b = 9.127(2) A, c = 15.637(3) A, and fl = 98.59(3)O. The structure has been refined to a final value for the crystallographic R factor of 0.0486 based on 1365 observed independent reflections. The ligand adopts a relatively extended conformation in the crystals, the torsion angles around the nominally single CC bonds linking the phen and pyrazole rings being 163.6 and 164.4', respectively. The copper-(11) complex [Cu(bpmp)(HzO)](ClO& crystallizes in the space group Pi of the triclinic system with two molecules in a cell of dimensions u = 8.6040(10) A, b = 10.499(2) A, c = 13.405(3) A, a! = 89.080(10)0, fl = 80.040(10)0, and y = 84.380(10)O. The structure has been refined to a final value for the crystallographic R factor of 0.0490 based on 3560 observed independent reflections. The cation adopts a five-coordinate geometry, the coordination being provided by two phen nitrogen atoms [N(l) and N(2)] and two pyrazole nitrogen atoms [N(3) and N(4)] from the ligand and by a water molecule. The geometry at copper is best described as trigonal bipyramidal, with one phenanthroline and one pyrazolyl nitrogen atom axial while the other phenanthroline and pyrazolyl nitrogen atoms and the water ligand are equatorial. The copper(I1) complex [Cu(bpmp)(H20)l2+ exhibits a reversible wave at 0.037 V us Ag/AgCl, attributable to the [Cu(bpmp)(H20)I2+/+ couple.
One new copper(II) complex of 2,9-dimethyl-1,10-phenanthroline viz., [Cu(dmp)Cl 2 (H 2 O)] has been synthesized and structurally characterized by using single crystal x-ray diffraction studies. The complex crystallizes in monoclinic crystal system having space group P2 1 . The copper(II) environment is distorted square pyramidal. Two molecules are present in the unit cell. Complex has been also characterized by elemental analysis, infrared, UV–visible, electron paramagnetic resonance and electrochemical studies. DNA binding activity of the complex has been measured by absorption spectroscopy. DNA cleavage activity of complex was measure using pBR322 DNA in the presence and absence of H 2 O 2 . The antibacterial activity of complex has been measured using agar disc diffusion method against E. coli, Citrobacter and Vibrio respectively.
2005 Copper(II) complexes of 1,10-phenanthroline-derived ligands
A series of copper(II) complexes of the type [Cu(L)] 2+ , where L = N,N 0 -dialkyl-1,10-phenanthroline-2,9-dimethanamine and R = methyl (L1), n-propyl (L2), isopropyl (L3), sec-butyl (L4), or tert-butyl (L5) group, have been synthesized. The interaction of the complexes with DNA has been studied by DNA fiber electron paramagnetic resonance (EPR) spectroscopy, emission, viscosity and electrochemical measurements and agarose gel electrophoresis. In the X-ray crystal structure of [Cu(HL2)Cl 2 ]NO 3 , copper(II) is coordinated to two ring nitrogens and one of the two secondary amine nitrogens of the side chains and two chloride ions as well and the coordination geometry is best described as trigonal bipyramidal distorted square based pyramidal (TBDSBP). Electronic and EPR spectral studies reveal that all the complexes in aqueous solution around pH 7 possess CuN 3 O 2 rather than CuN 4 O chromophore with one of the alkylamino side chain not involved in coordination. The structures of the complexes in aqueous solution around pH 7 change from distorted tetragonal to trigonal bipyramidal as the size of the alkyl group is increased. The observed changes in the physicochemical features of the complexes on binding to DNA suggest that the complexes, except [Cu(L5)] 2+ , bind to DNA with partial intercalation of the derivatised phen ring in between the DNA base pairs. Electrochemical studies reveal that the complexes prefer to bind to DNA in Cu(II) rather than Cu(I) oxidation state. Interestingly, [Cu(L5)] 2+ shows the highest DNA cleavage activity among all the present copper(II) complexes suggesting that the bulky N-tert-butyl group plays an important role in modifying the coordination environment around the copper(II) center, the Cu(II)/Cu(I) redox potential and hence the formation of activated oxidant responsible for the cleavage. These results were compared with those for bis(1,10-phenanthroline)copper(II), [Cu(phen) 2 ] 2+ .
Inorganica Chimica Acta, 2008
Syntheses, spectroscopic and structural characterizations of a series of Cu(I)-phenanthroline complexes are reported. A single crystal X-ray structure determination is recorded for CuNO 3 :dmp:MeCN (1:1:1), 'dmp' = 2,9-dimethyl-1,10-phenanthroline, showing it to be isomorphous with its previously studied tetrafluoroborate, perchlorate and hexafluorophosphate, and silver(I) perchlorate counterparts, the metal atom lying in a trigonal planar [(N^N)Cu(NCMe)] coordination environment, the anion not being coordinated. Structure (re-) determinations are also reported for a number of salts of the [Cu(dmp) 2 ] + cation: the perchlorate, isomorphous with numerous other salts, not only of copper(I), but also lithium(I)), also the unsolvated nitrate, and a solvated form of the chloride.