共查询到20条相似文献,搜索用时 15 毫秒
1.
Ivan Nemec Radovan Herchel Ingrid Svoboda ?ubor Dlháň Hartmut Fuess 《Inorganica chimica acta》2011,366(1):366-11903
Syntheses and crystal structures of nickel(II) complexes containing teta (teta = N,N′-bis(2-aminoethyl)ethane-1,2-diamine) as a tetradentate blocking ligand and cyanidometallic bridging complexes are described. The complexes [Ni(teta)(cis-μ2-Ni(CN)4)] (1) and [{Ni(teta)}3(μ6-Co(CN)6)] (ClO4)3 (2) exhibit a 1D-polymeric structure whereas the heterometallic trinuclear complex [Ni(teta)(μ1-Ag(CN)2)2] (3) forms a unique network. The weak antiferromagnetic exchange was found in polymeric species 1 and 2 by analyzing the magnetic data with several models in which either only susceptibility was treated or simultaneous fitting of temperature and magnetic field dependences of the magnetization was applied using the finite-size closed ring approach. Moreover, an effect of the zero-field splitting phenomenon (ZFS) was considered for 2 by advanced modeling of magnetic properties for varying axial ZFS parameter/isotropic exchange (D/J) ratios. 相似文献
2.
One lead(II) coordination polymer, {[Pb(fum)(phen)]·2H2O}n (fum = fumarate, phen = 1,10-phenanthroline), was synthesized through the self-assembly of the lead(II) ion with the mixed fum and phen ligands and characterized by FT-IR spectroscopy, elemental analysis, thermogravimetric analysis, X-ray analysis and solid state photoluminescence spectrum. The compound shows a center-symmetrical dinuclear-based 2D architecture and further assembles into porous 3D supramolecular framework with 1D channel via interlayer π-π stacking interactions. The six-coordinated lead atoms in the complex show hemidirected geometry. The compound exhibits photoluminescence with the maximum emission located in UV region. 相似文献
3.
Synthesis, crystal structure and DNA cleavage activity of a novel Ni(II)-Cd(II) coordination polymer
A novel one-dimensional heterometallic complex, {Cd2[NiL]2(SCN)4(H2O)}n (1), has been synthesized and characterized by single-crystal X-ray analysis, where L is dianion of 2,3-dioxo-5,6,13,14-dibenzo-9,10-cyclohexyl-7,12-bis(ethoxycarbonyl)-1,4,8,11-tetraazacyclotetradeca-7,11-diene. The most striking feature of 1 is that in the structure there is one type of S-S bond (1.823(13) Å) formed by two thiocyanate groups which has not been reported to our knowledge. The DNA cleavage activity of 1 in the presence of H2O2 was compared with those of nickel(II) ion, cadmium(II) ion and corresponding mononuclear precursor NiL (2). The DNA cleavage kinetics was studied and the corresponding activation parameters of 1 were obtained. 相似文献
4.
Bellam Sreenivasulu 《Inorganica chimica acta》2009,362(8):2735-281
Complexes [Cu(HSas)(H2O)] · 2H2O (H3Sas = N-(2-hydroxybenzyl)-l-aspartic acid) (1), [Cu(HMeSglu)(H2O)] · 2H2O (H3MeSglu = (N-(2-hydroxy-5-methylbenzyl)-l-glutamic acid) (2), [Cu2(Smet)2] (H2Smet = (N-(2-hydroxybenzyl)-l-methionine) (3), [Ni(HSas)(H2O)] (4), [Ni2(Smet)2(H2O)2] (5), and [Ni(HSapg)2] (H2Sapg = (N-(2-hydroxybenzyl)-l-aspargine) (6) have been synthesized and characterized by chemical and spectroscopic methods. Structural determination by single crystal X-ray diffraction studies revealed 1D coordination polymeric structures in 2 and 4, and hydrogen-bonded network structure in 5 and 6. In contrast to previously reported coordination compounds with similar ligands, the phenol remains protonated and bonded to the metal ions in 2 and 4, and also probably in 1. However, the phenolic group is non-bonded in 6. 相似文献
5.
Four new zinc(II) cyclams of the composition {Zn(L)(tp2−) · H2O}n (1), {Zn(L)(H2bta2−) · 2H2O}n (2), [Zn2(L)2(ox2−)] 2ClO4 · 2DMF (3), and Zn(L)(H2btc−)2 · 2DMF (4), where L = cyclam, tp2− = 1,4-benzenedicarboxylate ion, H2bta2− = 1,2,4,5-benzenetetracarboxylate ion, ox2− = oxalate ion, DMF = N,N-dimethylformamide, and H2btc− = 1,3,5-benzenetricarboxylate ion, have been synthesized and structurally characterized by a combination of analytical, spectroscopic and crystallographic methods. The carboxylato ligands in the complexes 1-4 show strong coordination tendencies toward zinc(II) cyclams with hydrogen bonding interactions between the pre-organized N-H groups of the macrocycle and oxygen atoms of the carboxylato ligands. The macrocycles in 1, 2, and 4 adopt trans-III configurations with the appropriate R,R,S,S arrangement of the four chiral nitrogen centers, respectively. However, the complex 3 shows an unusual cis V conformation with the R,R,R,R nitrogen configuration. The finding of strong interactions between the carboxylato ligands and the zinc(II) ions may provide additional knowledge for the improved design of receptor-targeted zinc(II) cyclams in anti-HIV agents. 相似文献
6.
Three new ligands, 1-(benzimidazolyl-2-methyl)-1,4,7-triazacyclononane L1, 1,4-bis(benzimidazolyl-2-methyl)-1,4,7-triazacyclonone L2, and 1,4,7-tris-(benzimidazolyl-2-methyl)-1,4,7-triazacyclonane L3, were synthesized by a straightforward one-pot method. Their nickel(II) complexes , [NiL2CH3CN](ClO4)2 · 2CH3OH · H2O (or [NiL2Cl] · ClO4) and [Ni(H−2L3)] · H2O were obtained and characterized by electrospray mass spectrum, 1H NMR, CV and other physical methods. Their crystal structures were determined by X-ray analyses. The crystal structure of the nickel(II) complex of L1 shows that two Ni(II) atoms are bridged by two Cl− anions. A ferromagnetic exchange coupling and zero-field splitting effect exist in complex 1. 相似文献
7.
A new bis-(N-tridentate) Fe(II) complex [Fe(dpop′)2](PF6)2 (dpop′=dipyrido(2,3-a:3′,2′-j)phenazine) was prepared and studied. The magnetic moment of the solid was determined as μ=5.2-4.9 BM and in CH3CN solution as μ=4.9 BM and indicate the high spin Fe(II) state. The electronic absorption spectrum displays a broad weak absorption MLCT transition at 602 nm (ε=3.8×103 M−1 cm−1), consistent with CT absorptions of other Fe(II) HS complexes. The cyclic voltammogram of the complex shows an irreversible Fe2+/3+ oxidation at +1.55 V and two dpop′0/−1 centered reductions at −0.20 and −0.59 V versus Ag/AgCl. 相似文献
8.
One-dimensional (1-D) helical coordination polymers, [MII(H2O)3(BPDC)]n · nH2O (M = Co (1), Fe (2)), have been prepared by the self-assembly of cobalt(II) and iron(II) ions, respectively, with 2,2′-bipyridyl-3,3′-dicarboxylic acid (H2BPDC) in an aqueous solution. X-ray crystal structures of compounds 1 and 2 show that each metal ion displays a distorted octahedral coordination geometry including three water oxygen atoms, one oxygen atom of the carboxylate of a BPDC2− belonging to the adjacent metal ion and two nitrogen atoms from the BPDC2− acting as a chelating ligand. In 1 and 2, one carboxylate oxygen atom of coordinated BPDC2− binds to the neighboring metal ion, which give rise to 1-D helical coordination polymers. The helical chains of 1 and 2 are linked by the hydrogen bonding interactions between the carboxylate oxygen atom of the BPDC2− ion belonging to a chain and the water molecule of the adjacent helical chain, which lead to 2-D networks extending along the ab plane. The supramolecules 1 and 2 show isomorphous structures regardless of the metal ions. 相似文献
9.
Fernandes AS Cabral MF Costa J Castro M Delgado R Drew MG Félix V 《Journal of inorganic biochemistry》2011,105(3):410-419
Two pentaaza macrocycles containing pyridine in the backbone, namely 3,6,9,12,18-pentaazabicyclo[12.3.1]octadeca-1(18),14,16-triene ([15]pyN5), and 3,6,10,13,19-pentaazabicyclo[13.3.1]nonadeca-1(19),15,17-triene ([16]pyN5), were synthesized in good yields. The acid-base behaviour of these compounds was studied by potentiometry at 298.2 K in aqueous solution and ionic strength 0.10 M in KNO3. The protonation sequence of [15]pyN5 was investigated by 1H NMR titration that also allowed the determination of protonation constants in D2O. Binding studies of the two ligands with Ca2+, Ni2+, Cu2+, Zn2+, Cd2+, and Pb2+ metal ions were performed under the same experimental conditions. The results showed that all the complexes formed with the 15-membered ligand, particularly those of Cu2+ and especially Ni2+, are thermodynamically more stable than with the larger macrocycle. Cyclic voltammetric data showed that the copper(II) complexes of the two macrocycles exhibited analogous behaviour, with a single quasi-reversible one-electron transfer reduction process assigned to the Cu(II)/Cu(I) couple. The UV-visible-near IR spectroscopic and magnetic moment data of the nickel(II) complexes in solution indicated a tetragonal distorted coordination geometry for the metal centre. X-band EPR spectra of the copper(II) complexes are consistent with distorted square pyramidal geometries. The crystal structure of [Cu([15]pyN5)]2+ determined by X-ray diffraction showed the copper(II) centre coordinated to all five macrocyclic nitrogen donors in a distorted square pyramidal environment. 相似文献
10.
A new ethyl bis(pyridin-2-ylmethyl)phosphate (2-bis(pm)Ope) ligand has been synthesized and used for synthesis of copper(II) and zinc(II) complexes of the formula [MCl2(2-bis(pm)Ope)] [M = Cu(II), Zn(II)]. Despite having the same general formula, Cu(II) and Zn(II) complexes are not isostructural. The Zn(II) complex is four coordinated (MCl2N2) forming probably tetrahedral structure whereas the Cu(II) complex of distorted square pyramidal geometry is five coordinated (MCl2ON2). The later compound not only coordinates by two nitrogen atoms of pyridine rings but also by the oxygen atom of pyridin-2-ylmethoxyl residue. The compound (2-bis(pm)Ope) has been obtained as the product of diethyl (pyridin-2-ylmethyl)phosphate’s (2-pmOpe) transestrification. The compounds have been identified and characterized by IR, far-IR, 1H NMR, 31P NMR and elemental analyses. The crystal structure of copper(II) complex i.e. [CuCl2(2-bis(pm)Ope)] has been determined by the X-ray diffraction method. The low temperature magnetic study reveals significant antiferromagnetic interaction between copper centers through the H-bond system. 相似文献
11.
Markus Fessler Sylvia Eller Stephan Haringer Peter Brüggeller 《Inorganica chimica acta》2010,363(9):2001-2008
The novel dimer of the composition [Pt2Cl4(μ-(κP1:κP2-o-MeO-trans-dppen))2] (1) (o-MeO-trans-dppen = 1,2-(bis(o-methoxyphenyl)phosphanyl)ethylene) has been prepared and characterized by a single crystal X-ray structure analysis, NMR spectroscopy, mass spectrometry and elemental analysis. This latter compound undergoes a [2+2] photocycloaddition reaction yielding the tetraphosphane all-trans-1,2,3,4-tetrakis(di(o-methoxyphenyl)phosphanyl)cyclobutane (o-MeO-dppcb). The X-ray structure of the dimeric Ni(II) complex that contains the latter ligand, of the formula [Ni2Cl4(μ-(κP1:κP2:κP3:κP4-o-MeO-dppcb))] (2) reveals that the apical coordination sites of both square pyramidal Ni(II) coordination spheres are occupied by methoxy-oxygen atoms of the ligand. As a consequence, this dimeric Ni(II) complex 2 is prone to a thermally induced regio- and diastereoselective metal-assisted methoxy-group cleavage. The stepwise formed new mono- and bis-phenolate complexes [Ni2Cl3(μ-(κO1,κP1:κP2:κP3:κP4-o-MeO-O-dppcb))] (3) and [Ni2Cl2(μ-(κO1,κP1:κP2:κO2,κP3:κP4-o-MeO-O,O′-dppcb))] (4), respectively, contain the novel chiral tetraphosphane ligands all-trans-1,2,3-tris((di-o-methoxyphenyl)phosphano)-4-((o-methoxy-phenyl)(o-phenolate)phosphano)cyclobutane (o-MeO-O-dppcb) and all-trans-1,2-bis((di-o-methoxyphenyl)phosphano)-3,4-bis((o-methoxyphenyl)(o-phenolate)phosphano)cyclobutane (o-MeO-O,O′-dppcb). Compounds 3 and 4 have been synthesized independently and are also fully characterized by both single crystal X-ray structure analyses, NMR spectroscopy, mass spectrometry and elemental analyses. The conversion of 2 into 3 and then further into 4 has been followed by a variable-temperature 31P{1H} NMR experiment with compound 2 in DMF-d7, revealing that the cleavage of the second methoxy group is kinetically disfavoured. This is in agreement with the X-ray structure analysis of 3, indicating the lack of any methoxy-oxygen atom coordination that could easily induce a further methoxy-group cleavage. o-MeO-O-dppcb and o-MeO-O,O′-dppcb are rare P-stereogenic tetraphosphine ligands and contribute to the synthetic field of new κ3-P,P,O-coordinating phosphanylphenolate ligands that are believed to be important for the SHOP process (SHOP, Shell Higher Olefin Process). 相似文献
12.
Hydrothermal reactions of cobalt(II) salt with H2CAM or H2SDBA and HBTA in the presence of NaOH afford two interesting coordination polymers, Co3(CAM)2(BTA)2 (1) and Co3(SDBA)2(BTA)2 (2) (H2CAM = camphoric acid, H2SDBA = 4,4′-dicarboxybiphenyl sulfone, HBTA = benzotriazole), both of which have been structurally characterized by single-crystal X-ray, elemental analysis, infrared spectroscopy, and thermogravimetric analysis. Complexes 1 and 2 are isostructural and possess two-dimensional covalent network, comprising an unusual linear Co(II) chains of mixed Td-Oh-Td geometries. Temperature-dependent magnetic measurements indicate the existence of antiferromagnetic interactions in both 1 and 2. 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.
Jian-Guo Lin Fang-Ming Wang Chang-Sheng Lu Pei-Heng Wu 《Inorganica chimica acta》2009,362(15):5219-5223
Employing the symmetrical ligand 1,2,3,4-tetra-(4-pyridyl)-butane (TPB) as bridges, two novel Zn(II) coordination polymers were obtained and characterized by single crystal X-ray diffraction: [Zn(TPB)0.5(NCS)2] (1) and [Zn(TPB)(N3)2] (2). Polymer 1 features a 2D network with herringbone structural motif constructed by TPB, while polymer 2 shows a dense 3D network connected by TPB and μ1,3-N3- bridges. In the former, the TPB ligand acts as a four-connector, while in the latter it acts as four-connector and linear bridge. Both 1 and 2 exhibit strong fluorescent emissions in the solid state, which may be of significance in the field of photoactive materials. 相似文献
15.
Two novel dinuclear nickel(II) complexes [Ni2(ntb)2(μ-tp)(H2O)1.61(CH3OH)0.39](NO3)2·5.13CH3OH·2.25H2O (1) and [Ni2(ntb)2(μ-fum)(H2O)(CH3OH)](NO3)2·6CH3OH·H2O (2) (tp = terephthalate dianion, fum = fumarate dianion, ntb = tris(2-benzimidazolylmethyl)amine) containing tetradentate poly-benzimidazole ligand were synthesized and structurally characterized by IR spectra, UV-Vis, elemental analysis and X-ray crystallography. The Ni(II) ions in 1 and 2 have distorted octahedral geometry with four nitrogen atoms of ntb, one oxygen atom of water and one oxygen atom supplied by the carboxylate group of the bridged dicarboxylato ligand. Complexes 1 and 2 consist of terephthalato- and fumarato-bridged dinickel(II) centers in bis(monodentate) bonding fashion. The Ni?Ni distances are 11.333 Å for 1 and 8.966 Å for 2. The magnetic susceptibility measurements at variable temperature show that two complexes exhibit weak antiferromagnetic interactions between nickel(II) ions with J values of −0.25 cm−1 and −0.36 cm−1, respectively. 相似文献
16.
Reaction of Ni(OAc)2 with the symmetric `end-off' compartmental proligand 2,6-[N,N′-bis(2-hydroxy-phenylmethyl)-N,N′-bis(2-pyridylmethyl)aminomethyl]-4-methylphenol (H3L) in the presence of NaPF6 has been found to generate a homotetranuclear nickel(II) complex [(Ni4HL)(L)(OAc)2(H2O)2(HOAc)2]PF6. The crystal structure of the complex reveals that the complex is donor asymmetric and that the extended supra-ligand periphery is maintained by a tight hydrogen-bond between two pendant phenol/phenoxy groups of adjacent ligands and by further tight hydrogen-bonds between coordinated acetic acid molecules and the remaining pendant phenols of the ligand, generating a double acid salt of the type [CH3COO?H?LH?L?H?OOCCH3]5−. Reaction of H3L with Ni(OAc)2 and NaClO4 in methanol gave the complex [Ni2(HL)(OAc)2(OH2)2][ClO4]. The structure was determined by X-ray diffraction and showed that the complex exists as a dimer promoted by intermolecular hydrogen-bonding. 相似文献
17.
New partially N-hydroxyethylated 14-membered tetraaza macrocycles 1,8-bis(2-hydroxyethyl)-3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradecane (L2) and 1-(2-hydroxyethyl))-3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradecane (L3) have been synthesized selectively by the one-step reaction of 2,5,5,7,9,12,12,14-octamethyl-1,4,8,11-tetraazacyclotetradecane (L1) with 2-hydroxyethyl bromide. The complexes [NiL3]2+, [CuL2]2+, and [CuL3]2+ have been prepared and characterized. The complex [CuL2](ClO4)2 has a square-pyramidal coordination geometry with one apical oxygen atom; only one of the two hydroxyethyl groups is coordinated to the metal ion. Electronic absorption spectra of [CuL3](ClO4)2 containing one hydroxyethyl pendant arm indicate that the geometry is similar to that of [CuL2](ClO4)2. Unexpectedly, the nickel(II) complex [NiL3](ClO4)2 has a severely distorted trigonal bipyramidal coordination geometry with the oxygen atom of the pendant arm at the equatorial position. The Ni---O bond distance of the nickel(II) complex is shorter, or not longer, than the Ni---N bond distances. The ligand in [CuL2]2+ is in the RRSS (trans-III) configuration, as usual, whereas that in [NiL3]2+ has the RRRR (trans-V) conformation. The coordination geometry and properties of [NiL3]2+ are quite different from those reported for other related nickel(II) complexes containing one functional pendant arm. 相似文献
18.
Wang QX Jiao K Liu FQ Yuan XL Sun W 《Journal of biochemical and biophysical methods》2007,70(3):427-433
A novel mixed-ligand nickel(II) complex that contains 1-methylimidazole and thiocyanate, Ni(NCS)(2)(Mim)(4) (Mim=1-methylimidazole), was synthesized and its structure was determined by X-ray crystallography, IR spectrum and elemental analysis, etc. Its DNA-binding properties were studied by electronic absorption spectral, viscositive and electrochemical measurements. The absorption spectral and viscositive results suggest that the nickel(II) complex binds to DNA via partial intercalation. The addition of DNA results in the decrease of the peak current of the nickel(II) complex proved their interaction. The slight differences of peak profiles and electrochemical parameters between free and DNA-bound Ni(NCS)(2)(Mim)(4) showed the formation of an electrochemical inactive complex between Ni(NCS)(2)(Mim)(4) and DNA. The binding site and binding constant of the complex to DNA were determined by electrochemical titration method. 相似文献
19.
Reaction of the symmetrical proligand H2L with metal(II) acetate and a counteranion to promote crystallisation has given the homodinuclear complexes [Zn2L(OAc)2](BF4)]·2MeOH and [Ni2L(OAc)2](BF4)]·2MeOH the crystal structures of which are reported. These show the presence of a triply bridging (μ-cresolato)bis(μ-carboxylato) dimetal core. 相似文献
20.
Hitoshi Kumagai Yoshimi Oka Motoko Akita-TanakaKatsuya Inoue 《Inorganica chimica acta》2002,332(1):176-180
The hydrothermal synthesis, single crystal X-ray structure and magnetic properties of a two-dimensional (2-D) coordination polymer, [Ni4(C6(COO)6)(OH)2(H2O)6] (1), is described. Complex 1 consists of dimer motifs of pseudo octahedral NiO6 linked through μ3-OH to generate one-dimensional (1-D) chains which are further bridged by the mellitate ligands to form non interpenetrated undulating sheet structure. The sheets are further connected by hydrogen bonding interaction to yield a three-dimensional (3-D) structure. The temperature dependence of magnetic susceptibilities revealed the presence of antiferromagnetic interaction between nickel centers. 相似文献