Search results for "bipyridine"
showing 10 items of 534 documents
Biomimetic Mn-catalases based on dimeric manganese complexes in mesoporous silica for potential antioxidant agent
2015
Two new structural and functional models of the Mn-catalase with formula [{Mn(III)(bpy)(H2O)}(μ-2-MeOC6H4CO2)2(μ-O){Mn(III)(bpy)(X)}]X, where X = NO3 (1) and ClO4 (2) and bpy = 2,2'-bipyridine, were synthesized and characterized by X-ray diffraction. In both cases, a water molecule and an X ion occupy the monodentate positions. The magnetic properties of these compounds reveal a weak antiferromagnetic behavior (2J = -2.2 cm(-1) for 1 and -0.7 cm(-1) for 2, using the spin Hamiltonian H = -2J S1·S2) and negative zero-field splitting parameter DMn (-4.6 cm(-1) and -3.0 cm(-1) for 1 and 2, respectively). This fact, together with the nearly orthogonal orientation of the Jahn-Teller axes of the M…
Synthesis, Crystal Structures, and Magnetic Properties of a New Family of Heterometallic Cyanide-Bridged FeIII2MII2 (M = Mn, Ni, and Co) Square Compl…
2011
New heterobimetallic tetranuclear complexes of formula [Fe(III){B(pz)(4)}(CN)(2)(μ-CN)Mn(II)(bpy)(2)](2)(ClO(4))(2)·CH(3)CN (1), [Fe(III){HB(pz)(3)}(CN)(2)(μ-CN)Ni(II)(dmphen)(2)](2)(ClO(4))(2)·2CH(3)OH (2a), [Fe(III){B(pz)(4)}(CN)(2)(μ-CN)Ni(II)(dmphen)(2)](2)(ClO(4))(2)·2CH(3)OH (2b), [Fe(III){HB(pz)(3)}(CN)(2)(μ-CN)Co(II)(dmphen)(2)](2)(ClO(4))(2)·2CH(3)OH (3a), and [Fe(III){B(pz)(4)}(CN)(2)(μ-CN)Co(II)(dmphen)(2)](2)(ClO(4))(2)·2CH(3)OH (3b), [HB(pz)(3)(-) = hydrotris(1-pyrazolyl)borate, B(Pz)(4)(-) = tetrakis(1-pyrazolyl)borate, dmphen = 2,9-dimethyl-1,10-phenanthroline, bpy = 2,2'-bipyridine] have been synthesized and structurally and magnetically characterized. Complexes 1-3b have be…
[Fe(bipy)(CN)4]- as a Versatile Building Block for the Design of Heterometallic Systems: Synthesis, Crystal Structure, and Magnetic Properties of PP…
2002
The new cyano complexes of formulas PPh4[FeIII(bipy)(CN)4]·H2O (1), [{FeIII(bipy)(CN)4}2MII(H2O)4]·4H2O with M = Mn (2) and Zn (3), and [{FeIII(bipy)(CN)4}2ZnII]·2H2O (4) [bipy = 2,2‘-bipyridine and PPh4 = tetraphenylphosphonium cation] have been synthesized and structurally characterized. The structure of complex 1 is made up of mononuclear [Fe(bipy)(CN)4]- anions, tetraphenyphosphonium cations, and water molecules of crystallization. The iron(III) is hexacoordinated with two nitrogen atoms of a chelating bipy and four carbon atoms of four terminal cyanide groups, building a distorted octahedron around the metal atom. The structure of complexes 2 and 3 consists of neutral centrosymmetric […
[Cr(AA)(C2O4)2]− and [Cu(bpca)]+ as building blocks in designing new oxalato-bridged CrIIICuII compounds [AA=2,2′-bipyridine and 1,10-phenanthroline…
2003
Abstract The monouclear complex PPh4[Cr(bipy)(ox)2]·H2O (1) and the heterodinuclear compounds [Cu(bpca)(H2O)Cr(bipy)(ox)2]·2.5H2O (2) and [Cu(bpca)(H2O)Cr(phen)(ox)2]·2H2O (3) [PPh4+=tetraphenylphosphonium cation, bpca=bis(2-pyridylcarbonyl)amide anion, ox=oxalate dianion, bipy=2,2′-bipyridine and phen=1,10-phenanthroline] have been synthesized and characterized by single-crystal X-ray diffraction. Discrete [Cr(bipy)(ox)2]− mononuclear anions and tetraphenylphosphonium cations are present in 1 whereas the structures of 2 and 3 are made up neutral oxalato-bridged bimetallic CrIIICuII units. The chromium environment is distorted octahedral in the three complexes: two nitrogen atoms from a bi…
Solvent-driven dimensionality control in molecular systems containing CuII, 2,2′-bipyridine and an oxamato-based ligand
2013
A discrete dicopper(II) system, [Cu(bipy)(H2mpba)]2·2H2O (1), and its isomeric chain, [Cu(bipy)(H2mpba)]·dmso (2) [bipy = 2,2′-bipyridine and H4mpba = N,N′-1,3-phenylenebis(oxamic acid)], were obtained by modifying the ratio of the H2O–dmso solvent mixture, and their interconversion was also monitored by changing the solvents during the synthesis. The solvents play an essential role in the formation and crystallization of these complexes, presenting different dimensionalities and connectivities. The double deprotonated H2mpba2− adopts the bidentate/monodentate (1) and bis-bidentate (2) bridging modes toward the (2,2′-bipyridyl)copper(II) units affording a dinuclear compound (1) and a linear…
Crystal structure and magnetic properties of the flexible self-assembled two-dimensional square network complex [Cu2(mal)2(H2O)2(4,4′-bpy)] (H2mal=ma…
2001
Abstract The copper(II) complex [Cu 2 (mal) 2 (H 2 O) 2 (4,4′-bpy)] ( 1 ) (H 2 mal=malonic acid and 4,4′-bpy=4,4′-bipyridine) has been prepared and its structure determined by single crystal X-diffraction methods. Compound 1 has a two-dimensional square grid network structure. The square grids are stacked parallel but in a staggered manner on each other along the c -axis, with an interlayer separation of 3.850(1) A. Each layer contains a large cavity of 15.784(1)×15.784(1) A with each edge shared by one malonate group and one 4,4′-bpy ligand and a small planar square of 4.644(1)×4.644(1) A with Cu(II) ions and malonate groups at each corner and side, respectively. Each copper atom is in a d…
Magneto-structural study on a series of rhenium(IV) complexes containing biimH2, pyim and bipy ligands
2008
Abstract Three rhenium(IV) mononuclear compounds of formulae [ReCl4(biimH2)] · 2DMF (1), [ReCl4(pyim)] · DMF (2) and [ReCl4(bipy)] (3) (biimH2 = 2,2′-biimidazole, pyim = 2-(2′-pyridyl)imidazole, bipy = 2,2′-bipyridine and DMF = N,N-dimethylformamide) have been prepared and characterized. The crystal structure of 2 was determined by single crystal X-ray diffraction. Compound 2 crystallizes in the monoclinic system with P21/c as space group. The rhenium atom is six-coordinated by four Cl atoms and two nitrogen atoms from a bidentate pyim ligand [average values of Re–Cl and Re–N bonds lengths being 2.330(2) and 2.117(4) A, respectively]. The magnetic properties were investigated from susceptib…
Influence of Copper(II) and Nickel(II) Ions in the Topology of Systems Based on a Flexible Bis-Oxamate and Bipyridine Building Blocks
2014
Single crystals of the mononuclear bis-oxamate nickel(II) complex [Ni(bipy)(H2edpba)]·dmso (1) are obtained by reacting [Ni(bipy)Cl2]·H2O and the flexible K2(H2edpba) ligand [bipy = 2,2′-bipyridine; H4edpba = N,N′-2,2′-ethylenediphenylenebis(oxamic acid)]. The reaction of 1 with copper(II) ions resulted in two products in which the replacement of the nickel(II) ion by copper(II) took place: the chain compound [Cu(bipy)(H2edpba)]n·3nH2O·ndmso [dmso = dimethyl sulfoxide] (2) and the analogous chain compound without dmso crystallization molecules [Cu(bipy)(H2edpba)]n·1.5nH2O (3a) in its polycrystalline form. The reaction of [Cu(bipy)Cl2] and K2(H2edpba) yielded single crystals of [Cu(bipy)(H2e…
Ligand-Based Charge-Transfer Luminescence in Ionic Cyclometalated Iridium(III) Complexes Bearing a Pyrene-Functionalized Bipyridine Ligand: A Joint T…
2012
Two new heteroleptic iridium(III) complexes [Ir(ppy)(2)(pyr(2)bpy)][PF(6)] ([1a][PF(6)]) and [Ir(dfppy)(2)(pyr(2)bpy)][PF(6)] ([2a][PF(6)]), where Hppy = 2-phenylpyridine, Hdfppy = 2-(3,5-difluorophenyl)pyridine, and pyr(2)bpy = 5,5'-bis(pyren-1-yl)-2,2'-bipyridine, have been synthesized and fully characterized. The single-crystal structures of pyr(2)bpy and the complexes 4{[1a][PF(6)]}·2CH(2)Cl(2)·9H(2)O and [2a][PF(6)]·0.25CH(2)Cl(2)·H(2)O have been determined. The effect of the pyrene substituents on the electronic properties is investigated through a comprehensive photophysical and theoretical study on the two complexes in comparison to reference complexes without substituents on the an…
A novel class of interpenetrated 3-D network of a dimeric cupric-tetracarboxylate unit
2002
The hydrothermal reaction of Cu(II), fumaric acid and 4,4′-bipyridine (bpy) in equimolar amounts at 160 °C resulted in a new type of two-fold interpenetrating 3-D coordination network composed of tetracarboxylate dicopper(II) units bridged by bipyridine spacers.