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1.
Oksana V. Nesterova Svitlana R. Petrusenko Vladimir N. Kokozay Jens K. Bjernemose 《Inorganica chimica acta》2005,358(9):2725-2738
Five novel heterometallic Ni/Zn coordination compounds [Ni(en)3][ZnCl4] (1), [Ni(en)(Hea)2][ZnCl4] (2), [Ni(dien)2][ZnCl4] (3), [Ni(en)3][ZnCl4] · 2DMSO (4) and [Ni(en)3][Zn(NCS)4] · CH3CN (5), where en = ethylenediamine (ethane-1,2-diamine), Hea = monoethanolamine (2-aminoethanol) and dien = diethylenetriamine (1,4,7-triazaheptane), have been synthesized by means of the open-air reaction of zinc oxide, nickel chloride (or nickel powder), NH4X (X = Cl, NCS) and ligand (en, dien, Hea) in non-aqueous solvents, such as DMSO, DMF, CH3OH and CH3CN. The choice of a counter-anion in the initial ammonium salt as well as selection of the ligand and solvent provides an effortless approach to the controlled assembly of two- or three-dimensional extended networks assisted by hydrogen bonding. Crystallographic investigations reveal that 1, 2 and 5 possess 3D, while 3 and 4 exhibit 2D H-bonded crystal structures. The structures of the compounds exhibit six-coordinated Ni(II) centers and four-coordinated Zn(II) centers in distorted octahedral and tetrahedral geometries, respectively. 相似文献
2.
Ahmet Karada? Ay?egül ?enocak Yusuf Yerli A. Cemil Ba?aran 《Inorganica chimica acta》2009,362(7):2299-278
Two unique bimetalic Pt(II) coordination polymers of composition [Ni(hydeten)2Pt(CN)4] (Ni-Pt) and [Cu(hydeten)2Pt(CN)4] (Cu-Pt) [hydeten = N-(2-hydroxyethyl-ethylenediamine) or 2-(2-aminoethylamino)ethanol] have been synthesized and structurally characterized by various methods in this study. The crystal structure of Cu-Pt was determined by single-crystal X-ray diffraction analysis. The structure of Cu-Pt forms of infinite 2,2-TT type [-Cu(hydeten)2-NC-Pt(CN)2-CN-] chains containing paramagnetic copper atoms bridged by tetracyanoplatinate species. In this complex, Cu(II) centers display an axially elongated octahedron with two chelating hydeten molecules in the equatorial positions and N-bonded bridging cyano groups in the axial positions, whereas Pt(II) centers are four coordinate with four cyanide-carbon atoms in a square-planar arrangement. The decrease of the moments of these complexes in temperature range of 50 305 K can assigned to the antiferromagnetic interactions in the structures. The thermal decomposition of Cu-Pt comprise of five distinguished stages, while the thermal decomposition of Ni-Pt take place four different stages. 相似文献
3.
A new series of dinuclear squarato-bridged nickel(II) and copper(II) complexes [Ni2(2,3,2-tet)2(μ1,3-C4O4)(H2O)2](ClO4)2 (1), [Ni2(aepn)2(μ1,3-C4O4)(H2O)2](ClO4)2 (2), [Cu2(pmedien)2(μ1,3-C4O4)(H2O)2](ClO4)2.4H2O (3) and [Cu2(DPA)2(μ1,2-C4O4)(H2O)2](ClO4)2 (4) where is the dianion of 3,4-dihydroxycyclobut-3-en-1,2-dione (squaric acid), 2,3,2-tet = 1,4,8,11-tetraazaundecane, aepn = N-(2-aminoethyl)-1,3-propanediamine, pmedien = N,N,N′,N″,N″-pentamethyldiethylenetriamine and DPA = di(2-pyridylmethyl)amine were synthesized and structurally characterized by X-ray crystallography. The spectral and structural characterization as well as the magnetic behaviour of these complexes is reported. In this series, structures consist of the groups as counter ions and the bridging the two M(II) centers in a μ-1,3- (1-3) and in a μ-1,2-bis(monodentate) (4) bonding fashions. The coordination geometry around the Ni(II) ions in 1 and 2 is six-coordinate with distorted octahedral environment achieved by N atoms of the amines and by one or two oxygen atoms from coordinated water molecules, respectively. In the Cu(II) complexes 3 and 4, a distorted square pyramidal geometry is achieved by the three N-atoms of the aepn or DPA and by an oxygen atom from a coordinated water molecule. The electronic spectra of the complexes in aqueous solutions are in complete agreement with the assigned X-ray geometry around the M(II) centers. The complexes show weak antiferromagnetic coupling with ∣J∣ = 1.8-4.2 cm−1 in the μ-1,3- bridged squarato compounds 1-3, and J = −16.1 cm−1 in the corresponding μ-1,2- bridged squarato complex 4. The magnetic properties are discussed in relation to the structural data. 相似文献
4.
Herein, we report the syntheses, spectral and structural characterization, and magnetic behavior of four new dinuclear terephthalato-bridged copper(II) complexes with formulae [Cu2(trpn)2(μ-tp)](ClO4)2 · 2H2O (1), [Cu2(aepn)2(μ-tp)(ClO4)2] (2), [Cu2(Medpt)2(μ-tp)(H2O)2](ClO4)2 (3) and [Cu2(Et2dien)2(μ-tp)(H2O)](ClO4)2 (4) where tp = terephthalate dianion, trpn = tris(3-aminopropyl)-amin, aepn = N-(2-aminoethyl)-1,3-propanediamine, Medpt = 3,3′-diamino-N-methyldipropylmine and Et2dien = N,N-diethyldiethylenetriamine. The structures of these complexes consist of two μ-tp bridging Cu(II) centers in a bis(monodentate) bonding fashion. The coordination geometry of the Cu(II) ions in these compounds may be described as close to square-based pyramid (SP) with severe significant distortion towards trigonal bipyramid (TBP) stereochemistry in 1. The visible spectra of the complexes in aqueous solutions are in complete agreement with the assigned X-ray geometry around the Cu(II) centers. Also, the solid infrared spectral data for the stretching frequencies of the tp-carboxalato groups, the ν(COO−) reveals the existence of bis(monodentate) coordination mode for the bridged terephthalate ligand. The susceptibility measurements at variable temperature over the range 2-300 K are reported. Despite the same bonding mode of the tp bridging ligand, there has been observed slight antiferromagnetic coupling for the compounds 1 and 4 with J values of −0.5 and −2.9 cm3 K mol−1, respectively, and very weak ferromagnetic coupling for 2 and 3 with J values of 0.8 and 10.1 cm3 K mol−1, respectively. The magnetic results are discussed in relation to other related μ-terephthalato dinuclear Cu(II) published compounds. 相似文献
5.
The dinuclear dicarboxylato-bridged copper(II) complexes [Cu2(TPA)2(μ-tp)](ClO4)2 · H2O (1), [Cu2(TPA)2(μ-fum)](ClO4)2 · 2H2O (2) and [Cu2(pmedien)2(μ-fum)(H2O)2](ClO4)2 (3) (tp = terephthalate dianion, fum = fumarate dianion, TPA = tris(2-pyridylmethyl)amine and pmedien = N,N,N′,N″,N″-pentamethyldiethylenetriamine) were synthesized and structurally characterized by X-ray crystallography. The structures of the TPA complexes 1 and 2 consist of μ-tp or μ-fum bridging two Cu(II) centers in a bis(monodentate) bonding fashion. The coordination geometry around the Cu(II) ions in these compounds has a distorted trigonal bipyamidal geometry, TBP with four nitrogen atoms from the TPA ligand and a coordinated oxygen atom supplied by the carboxylate group of the bridged dicarboxylato ligand. Complex 3 has a distorted square pyramidal geometry achieved by the three N-atoms of the pmedien, one fum-carboxylate-oxygen and by an oxygen atom from a coordinated water molecule. The intradimer Cu…Cu distances in these complexes are 11.078(3), 8.663(4) and 9.520(3) Å for 1, 2 and 3, respectively. The electronic spectra of the complexes in aqueous solutions are in complete agreement with the assigned X-ray geometry around the Cu(II) centers. Also, analysis of the infrared spectral data for the ν(COO−) stretching frequencies of the tp-carboxalato groups reveals the existence of the bis(mondentate) coordination mode for the bridged dicarboxylato ligands in compounds 1 and 2. The susceptibility measurements at variable temperature over the 2-300 K range are reported. For 1-3, it has been observed slight antiferromagnetic coupling with J values of −0.8, −3.0 and −2.9 cm−1, respectively. 相似文献
6.
Ruíz P Ortiz R Perelló L Alzuet G González-Alvarez M Liu-González M Sanz-Ruíz F 《Journal of inorganic biochemistry》2007,101(5):831-840
Three new binary Cu(II) complexes of norfloxacin have been synthesized and characterized. We also report the synthesis, characterization and X-ray crystallographic structures of a new binary compound, [Cu(HNor)(2)]Cl(2).2H(2)O (2) and two new ternary complexes norfloxacin-copper(II)-phen, [Cu(Nor)(phen)(H(2)O)](NO(3)).3H(2)O (4), and [Cu(HNor)(phen)(NO(3))](NO(3)).3H(2)O (5). The structure of 2 consists of two crystallographically independent cationic monomeric units of [Cu(HNor)(2)](2+), chloride anions, and uncoordinated water molecules. The Cu(II) ion is placed at a center of symmetry and is coordinated to two norfloxacin ligands which are related through the inversion center. The structures of 4 and 5 consist of cationic units ([Cu(Nor)(phen)(H(2)O)](+) for 4 and [Cu(HNor)(phen)(NO(3))](+) for 5), nitrate counteranions, and lattice water molecules that provide crystalline stability through a network of hydrogen-bond interactions. The complexes exhibit a five coordinated motif in a square pyramidal environment around the metal center. The ability of compounds 4 and 5 to cleave DNA has also been studied. Mechanistic studies with different inhibiting reagents reveal that hydroxyl radicals, singlet oxygen, and superoxide radicals are all involved in the DNA scission process mediated by these compounds. 相似文献
7.
The preparation and variable temperature-magnetic investigation of three squarate-containing complexes of formula [Fe2(OH)2(C4O4)2(H2O)4]·2H2O (1) [Cr2(OH)2(C4O4)2(H2O)4]·2H2O (2) and [Co(C4O4)(H2O)4]n (3) [H2C4O4 = 3.4-dihydroxycyclobutene-1,2-dione (squaric acid)] together with the crystal structures of 1 and 3 are reported. Complex 1 contains discrete centrosymmetric [Fe2(OH)2(C4O4)2(H2O)4] diiron(II) units where the iron pairs are joined by a di-μ-hydroxo bridge and two squarate ligands acting as bridging groups through adjacent oxygen atoms. Two coordinated water molecules in cis position complete the octahedral environment at each iron atom in 1. The iron-iron distance with the dinuclear unit is 3.0722(6) Å and the angle at the hydroxo bridge is 99.99(7)°, values which compare well with the corresponding ones in the isostructural compound 2 (2.998 Å and 99.47°) whose structure was reported previously. The crystal structure of 3 contains neutral chains of squarato-O1,O3-bridged cobalt(II) ions where four coordinated water molecules complete the six-coordination at each cobalt atom. The cobalt-cobalt separation across the squarate bridge is 8.0595(4) Å. A relatively important intramolecular antiferromagnetic coupling occurs in 1 whereas it is very weak in 2, the exchange pathway being the same [J = −14.4 (1) and −0.07 cm−1 (2), the spin Hamiltonian being defined as ]. A weak intrachain antiferromagnetic interaction between the high-spin cobalt(II) ions occurs in 3 (J = −0.30 cm−1). The magnitude and nature of these magnetic interactions are discussed in the light of their respective structures and they are compared with those reported for related systems. 相似文献
8.
Montserrat Barquín María J. González Garmendia Elena Pinilla María R. Torres 《Inorganica chimica acta》2009,362(7):2334-12
By the reactions of Cu(OAc)2 · H2O and Cu(HCOO)2 · 4H2O with 2-(aminomethyl)pyridine in different proportions, the compounds Cu(OAc)2(2-amp) (1), Cu(HCOO)2(2-amp) (2), Cu(HCOO)2(2-amp)1/2 (5), Cu(OAc)2(2-amp)2 · H2O (6) and Cu(HCOO)2(2-amp)2 · H2O (7) were obtained. In 1 the copper shows an elongated rhombic octahedral stereochemistry determined by a 2-amp molecule and two asymmetrical bidentate acetate groups. The hydrogen bonds between the NH2 groups and O atoms yield to the formation of a double chain. Compound 2 instead consists in monodimensional chains of Cu(2-amp)(HCOO) units, with monodentate formate groups, linked by syn-anti bridging formate groups. Sheets are formed by hydrogen bonds between the chains. By crystallization of a solution of 6 in chloroform, CuCl2(2-amp)2 (3) was obtained. It presents a highly distorted square pyramidal geometry around the copper atom. The sheets, formed by the hydrogen bonds between NH2 and Cl, are interpenetrated and shows π stacking. Magnetic properties and EPR spectra for these new compounds have been studied. Also the magnetic behaviour of Cu(OAc)2(2-amp)1/2 (4) is described. 相似文献
9.
The synthesis, structural characterization and magnetic property of two new coordination polymers [Cu(pyz)(μ-CH3CO2)4]n (1) and [Cu(pyz)(μ-CCl3CO2)4]n (2) (pyz = pyrazine) are reported. Here, the carboxylato bridged two dinuclear copper(II) complexes are linked through pyrazine giving a 1-D alternating chain. The magnetic property of the complexes indicates a significant difference originated from the introduction of electron withdrawing substituent on the bridging dicarboxylate. Complex 1 exhibits strong antiferromagnetic interactions with J = −344.61 cm−1, whereas 2 exhibits comparatively less strong antiferromagnetic coupling with J = −238.53 cm−1. 相似文献
10.
A series of new binuclear copper (II) and nickel (II) complexes of the macrocyclic ligands bis(1,4,7-triazacyclononan-1-yl)butane (Lbut) and bis(1,4,7-triazacyclononan-1-yl)-m-xylene (Lmx) have been synthesized: [Cu2LbutBr4] (1), [Cu2Lbut(imidazole)2Br2](ClO4)2 (2), [Cu2Lmx(μ-OH)(imidazole)2](ClO4)3 (3), [Cu2Lbut(imidazole)4](ClO4)4 · H2O (4), [Cu2Lmx(imidazole)4](ClO4)4 (5), [Ni2 Lbut(H2O)6](ClO4)4 · 2H2O (6), [Ni2Lbut(imidazole)6](ClO4)4 · 2H2O (7) and [Ni2Lmx (imidazole)4(H2O)2](ClO4)4 · 3H2O (8). Complexes 1, 2, 7 and 8 have been characterized by single crystal X-ray studies. In each of the complexes, the two tridentate 1,4,7-triazacyclononane rings of the ligand facially coordinate to separate metal centres. The distorted square-pyramidal coordination sphere of the copper (II) centres is completed by bromide anions in the case of 1 and/or monodentate imidazole ligands in complexes 2, 4 and 5. Complex 3 has been formulated as a monohydroxo-bridged complex featuring two terminal imidazole ligands. Complexes 6-8 feature distorted octahedral nickel (II) centres with water and/or monodentate imidazole ligands occupying the remaining coordination sites. Within the crystal structures, the ligands adopt trans conformations, with the two metal binding compartments widely separated, perhaps as a consequence of electrostatic repulsion between the cationic metal centres. The imidazole-bearing complexes may be viewed as simple models for the coordinative interaction of the binuclear complexes of bis (tacn) ligands with protein molecules bearing multiple surface-exposed histidine residues. 相似文献
11.
A series of Ni(II) and Cu(II) complexes of the hexaaza macrocycles, 3,6,9,17,20,23-hexaazatricyclo[23.3.1.111,15]triaconta-1(29),11(30),12,14,25,27-hexaene (L1) and 3,6,9,16,19,22-hexaazatricyclo[22.2.2.211,14]triaconta-1(26),11(29),12,14(30),24(28),25-hexaene (L2), have been prepared and the crystal structures determined for [Ni2L1(O2CCH3)2(H2O)2](ClO4)2 (1), [Ni2L2(DMF)6](ClO4)4 · 2H2O (2), {[Cu2L2Br(O2CCH3)](ClO4)2}n (3), [Cu2L2(μ-CO3)(H2O)2]2(ClO4)4 · 8H2O (4), [Cu2L2(O2CCH3)2](BF4)2 (5), and [Cu2L1(μ-imidazolate)Br]2Br4 · 6H2O (6). In these complexes, two metal centers are bound per ligand; in 1 and 3-6, the N3 subunits of L1 or L2 coordinate meridionally to the metal centers, whilst in 2, each N3 subunit in L2 adopts a facial mode of coordination. The binuclear cations in 1 and 2 have chair-like conformations, with the distorted octahedral Ni(II) coordination spheres completed by terminal water and a bidentate acetate ligand in 1 and three DMF ligands in 2. The Cu(II) centers in 3-6 generally reside in square planar environments, although a weakly binding ligand enters the coordination sphere in some cases, generating a distorted square pyramidal geometry. The binuclear [Cu2L2]4+ units in 3, 4 and 5 adopt similar bowl-shaped conformations, stabilized by H-bonding interactions between pairs of amine groups from L2 and a perchlorate or tetrafluoroborate anion. In 3, the binuclear units are linked through acetate groups, bridging in a syn-anti fashion, to produce a zig-zag polymeric chain structure, whilst 4 incorporates a tetrameric cation consisting of two binuclear units linked via a pair of carbonate bridges. Compound 6 features an imidazolate bridge between the two Cu(II) centers bound by L1. Pairs of [Cu2L1(μ-imidazolate)]3+ units are then weakly linked through a pair of bromide anions. 相似文献
12.
Bárbara Lúcia de Almeida Marta Sousa Antônio Sálvio Mangrich 《Inorganica chimica acta》2009,362(7):2447-4800
Four new complexes of Cu(II) of stoichiometry [Cu(ATP)(polyamine)] containing as ligands the polyamines (PA) ethylenediamine, 1,3-diaminopropane, spermidine or spermine and adenosine 5′triphosphate were prepared from aqueous solution at pH 6. The synthesis, characterization, thermogravimetric, vibrational spectroscopy, electron paramagnetic resonance analyses are described and show that these complexes have similar molecular structures. The infrared spectra and the thermal analysis are briefly discussed based on the peculiarities of the complexes. The IR spectra of the ligands and their copper complexes were used to assign the various groups and compare the shifts due to complexation. The EPR parameters values for the complexes show that Cu(II) is complexed in a similar way in the four complexes. Similarity in the coordination mode of complexes in solid state has been determined and discussed. The data obtained suggest that the four complexes present one water molecule of hydration and are complexed through two oxygen atoms from ATP and through two nitrogen atoms of each polyamine. 相似文献
13.
Two complexes of the formula [MH3L](ClO4)2 [M = Cu(II) (1), Ni(II) (2)] have been prepared by the reaction of M(ClO4)2 · 6H2O with the ligand (H3L) formed by the Schiff base condensation of tris(2-aminoethyl)amine (tren) with three molar equivalents of 4-methyl-5-imidazolecarboxaldehyde and structurally and magnetically characterized. The structures of 1 and 2 are isomorphous with each other and with the iron(II) complex of H3L which has been reported previously. The ligand, while potentially heptadentate, forms six coordinate complexes with both metal centers forming three M-Nimine and three M-Nimidazole bonds. The tren central N atom is at a nonbonded distance from M of 3.261 Å for 1 and 3.329 Å for 2. The neutral complex CuHL 3 was prepared by reaction of H3L with Cu(OCH3)2 and the ionic complex Na[NiL] 4 was prepared by deprotonation of 2 with aqueous sodium hydroxide. Magnetic measurements of 1-3 are consistent with the spin-only values expected for S = 1/2 (d9, Cu(II)) and S = 1 (d8, Ni (II)) systems. 相似文献
14.
Two new polynuclear complexes of Cu(II), [(μ-1,1,3-N3)2{Cu2(me2tn)2(N3)2}]n (1) (me2tn=2,2-dimethylpropane-1,3-diamine) and [Cu2(μ-C2O4)(μ-N3)(ipr2en)2]n(ClO4)n (2) (ipr2en=N,N′-di-isopropylethane-1,2-diamine) have been synthesized and structurally characterized by X-ray crystallography. The crystal structure of 1 displays a 2D network in which distorted octahedral copper(II) centers, chelated by a me2tn ligand and bound to a terminal azide, are connected through μ-1,1,3 bridging azide anions. The structure of 2 shows 1D chains comprising alternating [(ipr2en)Cu-Ox-Cu(ipr2en)] units and end-to-end azide ligand. The chains on mutual H-bonding interaction through ClO4−, give rise to a 2D supramolecular architecture. The magnetic data of complexes were recorded in the temperature range, 300-2 K. In case of complex 1, the magnetic data are consistent with a ferromagnetic interaction through the end-on azide bridge (JFM=10 cm−1) and a weak antiferromagnetic interaction (zj=−0.8 cm−1) between the ferromagnetically coupled dimers and an average g-value of 2.05. The susceptibility data of 2 were fitted using an alternating AF-AF chain spin 1/2 law which leads to the following parameters Joxalate=−180 cm−1, Jazide=−43 cm−1 and g=2.25 cm−1. 相似文献
15.
Yongshu Xie Hui Jiang Albert Sun-Chi ChanQingliang Liu Xiaolong XuChenxia Du Yu Zhu 《Inorganica chimica acta》2002,333(1):138-143
Two copper(II) complexes [Cu4(L1)4] (1) and [Cu2(phen)2(HL2)2] (ClO4)2 (2) have been synthesized from two potentially tridentate ligands N-(2-hydroxybenzyl) propanolamine (H2L1) and N-(2-hydroxybenzyl) ethanolamine (H2L2). X-ray analyses revealed that 1 contains a Cu4O4 cubane core, with each two Cu(II) atoms bridged by a pair of alkoxides; 2 has a bis(μ2-phenoxo)-bridged dicopper(II) structure. Variable temperature magnetic measurements of 1 have revealed that the correlation between 2J and the bridge angles φ for 1 shows a very strong antiferromagnetic tendency, i.e. the ferromagnetic and antiferromagnetic interactions cross at the φ of 94.5°. The relatively weak antiferromagnetic interactions (2J=−226.8 cm−1) with respect to the bridge angles (φ=100.4°) for 2 have been ascribed to the pyramidal distortions at the phenoxide oxygen atoms in addition to the unfavorable overlaps of the magnetic orbitals for the highly distorted copper coordination polyhedra. 相似文献
16.
Two new copper(II) complexes of the type [Cu(L)X2), where L = (E)-N-phenyl-2-[phenyl (pyridine-2-yl)methylene]hydrazinecarboxamide X = Cl/Br have been synthesized and characterized by elemental analyses, FAB (fast atomic bombardment) magnetic measurements, electronic absorption, conductivity measurements cyclic voltammetry (CV) and Electron paramagnetic resonance (epr) spectroscopy. The structures of these complexes determined by single crystal X-ray crystallography show a distorted square based pyramidal (DSBP) geometry around copper(II) metal center. The distorted CuN2OX (X = Cl/Br) basal plane in them is comprised of two nitrogen and one oxygen atoms of the meridionally coordinated ligand and a chloride or bromide ion and axial position is occupied by other halide ion. The epr spectra of these complexes in frozen solutions of DMSO showed a signal at g ca. 2. The trend in g-value (g|| > g⊥ > 2.00) suggest that the unpaired electron on copper(II) has dx2-y2 character. Biological activities in terms of superoxide dismutase (SOD) and antimicrobial properties of copper(II) complexes have also been measured. The superoxide dismutase activity reveals that these two complexes catalyze the fast disproportionation of superoxide in DMSO solution. 相似文献
17.
Two copper(II) complexes, [Cu(qsal)Cl](DMF) (1) and [Cu2(qsalBr)2Cl2](DMF) (2), with tridentate Schiff base ligands, 8-(salicylideneamino)quinoline (Hqsal) and 8-(5-bromo-salicylideneamino)quinoline (HqsalBr), respectively, were synthesised and structurally characterized. Each copper(II) ion in the two complexes is in a distorted square pyramidal N2OCl2 environment. Complex 1 exists as a polymeric species via equatorial-apical chloride bridges, whereas 2 is a di-chlorido-bridged dinuclear complex, where each bridging chloride simultaneously occupies an in-plane coordination site on one copper(II) ion and an apical site on the other copper(II) ion. Variable-temperature magnetical susceptibility measurements on the two complexes in the temperature range 2-300 K indicate the occurrence of intrachain ferromagnetic (J = +6.58 cm−1) and intramolecular antiferromagnetical (J = −6.91 cm−1) interactions. 相似文献
18.
Danielle Cangussu Humberto O. Stumpf Jim A. Thomas Miguel Julve 《Inorganica chimica acta》2005,358(7):2292-2302
The preparation and magnetic properties of three copper(II) compounds of formulae [Cu2(bpcam)2(H2O)2(C2O4)] (1), [Cu2(bpcam)2(H2O)4(C4O4)] · 10 H2O (2) and Cu2(bpcam)2(C5O5)(H2O)3 (3) [bpcam = bis(2-pyrimidyl)amidate, and are reported. The structures of two of them (1 and 2) have been solved by single crystal X-ray diffraction and consists of centrosymmetric discrete copper(II) dinuclear units bridged by bis-bidentate oxalate (1) and bis-monodentate squarate (2), with the bpcam group acting as a terminal tridentate ligand. Each copper atom in 1 exhibits a distorted elongated octahedral coordination geometry. Three bpcam nitrogen atoms and one oxalate oxygen define the basal plane while the other oxalate oxygen and a water molecule take up the axial positions. Each copper atom in 2 is in an elongated octahedral surrounding with three bpcam nitrogen atoms and one squarate oxygen in the equatorial plane and two water molecules in the axial positions. The intramolecular copper-copper separations are 5.677(1) (1) and 7.819(53) Å (2). Magnetic susceptibility measurements for 1-3 in the temperature range 1.9-290 K show the occurrence of weak ferromagnetic interactions through oxalato (J = +0.75 cm−1) and squarato (J = +1.26 cm−1), the Hamiltonian being defined by . These values are analyzed and discussed in the light of the available magneto-structural data for analogous systems. The quasi-Curie law observed in 3 (θ = −1.15 K) contrasts with the significant antiferromagnetic interaction through bis-chelating croconate in other structurally characterized croconate-bridged copper(II) complexes and rules out the presence of bridging croconate in this compound. 相似文献
19.
Nirmal K. Shee F.A. Oluwafunmilayo Adekunle Michael G.B. Drew 《Inorganica chimica acta》2011,366(1):198-202
Reaction of 5,6-dihydro-5,6-epoxy-1,10-phenanthroline (L) with Cu(ClO4)2·6H2O in methanol in 3:1 M ratio at room temperature yields light green [CuL3](ClO4)2·H2O (1). The X-ray crystal structure of the hemi acetonitrile solvate [CuL3](ClO4)2·0.5CH3CN has been determined which shows Jahn-Teller distortion in the CuN6 core present in the cation [CuL3]2+. Complex 1 gives an axial EPR spectrum in acetonitrile-toluene glass with g|| = 2.262 (A|| = 169 × 10−4 cm−1) and g⊥ = 2.069. The Cu(II/I) potential in 1 in CH2Cl2 at a glassy carbon electrode is 0.32 V versus NHE. This potential does not change with the addition of extra L in the medium implicating generation of a six-coordinate copper(I) species [CuL3]+ in solution. B3LYP/LanL2DZ calculations show that the six Cu-N bond distances in [CuL3]+ are 2.33, 2.25, 2.32, 2.25, 2.28 and 2.25 Å while the ideal Cu(I)-N bond length in a symmetric Cu(I)N6 moiety is estimated as 2.25 Å. Reaction of L with Cu(CH3CN)4ClO4 in dehydrated methanol at room temperature even in 4:1 M proportion yields [CuL2]ClO4 (2). Its 1H NMR spectrum indicates that the metal in [CuL2]+ is tetrahedral. The Cu(II/I) potential in 2 is found to be 0.68 V versus NHE in CH2Cl2 at a glassy carbon electrode. In presence of excess L, 2 yields the cyclic voltammogram of 1. From 1H NMR titration, the free energy of binding of L to [CuL2]+ to produce [CuL3]+ in CD2Cl2 at 298 K is estimated as −11.7 (±0.2) kJ mol−1. 相似文献
20.
Elena Maria Mosoarca Ingo Pantenburg Gerd Meyer Adelina Han Reni Kalfin Otilia Costisor 《Inorganica chimica acta》2011,370(1):460-468
The compound [Cu(TAMEN)][Cu(NCS)2Cl](DMF)2 containing the Mannich base N,N′-tetra-(4-antipyrylmethyl)-1,2-diaminoethane (TAMEN), as ligand, was synthesized and characterized by conductometric, magnetic, electronic and infrared spectroscopic properties. The single-crystal X-ray structure shows the presence of two well defined complex units, [Cu(TAMEN)]2+ and [Cu(NCS)2Cl]2−.The complex cation contains copper(II) in the elongated pseudo-octahedral environment created by the N2O4 donor set of TAMEN whereas, the counterion exhibits a pseudo trigonal planar geometry around the Cu(I) ion.Both, the pyrazolonic ligand and the complex have been screened for their cytotoxic activity against human tumor cell lines: glioblastoma multiforme, breast cancer, hepatoma and lung carcinoma. The nontumor cell lines MDBK (bovine kidney) and BALB/c 3T3 clone 31 (mouse embryo) were also included in the experiments. In contrast to the ligand TAMEN, the [Cu(TAMEN)][Cu(NCS)2Cl](DMF)2 was found to decrease in a time- and concentration-dependent manner the viability of cultured tumor (MCF-7, A549, 8MGBA, Hep G2) and non-tumor (MDBK, BALB/c 3T3) cell lines. 相似文献