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991.
《Journal of Coordination Chemistry》2012,65(16-18):2632-2645
AbstractBy changing the ancillary ligands, three new zinc-based coordination polymers (CPs), {[Zn(4,4′-bpy)(H2O)4]·(TDC)·(H2O)}n (1), [Zn(2,2′-dmbpy)(TDC)]n (2), and [Zn2(3,3′-dmbpy)(TDC)2]n (3) (H2TDC =2,5-thiophenedicarboxylic acid, 4,4′-bpy =4,4′-bipyridine, 2,2′-dmbpy =2,2′-dimethyl-4,4′-bipyridine, 3,3′-dmbpy =3,3′-dimethyl-4,4′-bipyridine) have been synthesized under the same reaction conditions (H2O, pH =7–8, and 140°C) and were structurally characterized. 1 is a linear chain structure and further connected into a 3-D structure through hydrogen bonds. 2 shows a 2-D (4,4) network when the dinuclear [Zn2(COO)4N2] building unit is regarded as a six-connected node. 3 has a twofold-interpenetrating 3-D zinc-organic framework pcu topology. Furthermore, 1–3 show strong photoluminescence at room temperature in the solid state, and the catalytic activities of 1–3 for degradation of methyl orange in a Fenton-like process have been investigated. The results suggest that the ancillary ligands influence the final resulting CPs. 相似文献
992.
《Journal of Coordination Chemistry》2012,65(19):3139-3179
AbstractInverse coordination is an emerging novel chemical concept describing the formation of metal complexes in which the arrangement of acceptor and donor sites is opposite to that occurring in conventional coordination complexes. Inverse coordination complexes are formed around a non-metal species as central atom (ion or small molecule) surrounded by a number of metal atoms (ions) connected or not by internal bridging (intramolecular) linkers. This article illustrates the diversity of species described under this concept with structures in which the coordination center is nitrogen (mono- and poly-nitrogen moieties). 相似文献
993.
《Journal of Coordination Chemistry》2012,65(23):4230-4244
Heterobimetallic complexes [Cu x Zn1? x (dadb)?·?yH2O] n {where dadb?=?2,5-diamino-3,6-dichloro-1,4-benzoquinone (1); x?=?1 (2), 0.5 (4), 0.25 (5), 0.125 (6), 0.0625 (7), and 0 (3); y?=?2; n?=?degree of polymerization} were synthesized and characterized. All metal complexes are stable at room temperature but weakly absorb moisture on exposure to air. Monometallic 2 exhibits subnormal magnetic moment whereas 3 exhibits diamagnetism. Heterobimetallic complexes exhibit normal magnetic moments. Heterobimetallic complexes are characterized from powder X-ray diffraction, thermal analysis, and electron spin resonance (ESR) spectral studies. Delocalization of unpaired electron from metal to ligand has been inferred from ESR and natural bond orbital (NBO) analysis. Greater delocalization of unpaired electron of Cu(II) on ligand of 4 as compared to that of 2 is reflected from NBO analysis. Heterobimetallic complexes show higher conductivity than monometallic complexes; all the complexes exhibit semiconductor behavior. 相似文献
994.
《Journal of Coordination Chemistry》2012,65(14):2310-2325
AbstractA new tridentate Schiff base ligand, 2-((2-(dimethylamino)ethylimino)methyl)-6-ethoxyphenol (HL1), has been prepared by a one-pot condensation reactions, which was further used in the construction of three novel Schiff base transition metal(II) complexes, [Cu(L1)(MeOH)](NO3) (1), [Co(L1)(MeOH)2(N3)] (2) and [Cu(L1)(HCOO)]n (3). Furthermore, a green hand-grinding technique has been implemented to reduce the particle size of the coordination complexes to generate the nanoscale compounds. The Scanning Electron Microscopy (SEM) studies reveal the formation of square and spherical particles for nano 1 and nanorod for nano 2 and 3. In addition, CCK-8 assay was conducted to detect the antiproliferative activity of nano 1–3 on human gastric cancer MGC-803 cells. The cell viability curves and IC50 (half maximal inhibitory concentration) values indicated that only nano 1 has excellent anticancer activity on MGC-803 cells but not nano 2 and 3. The Annexin V-FITC/PI double staining assay and DCFH-DA staining were performed to detect the apoptosis of MGC-803 cancer cells. 相似文献
995.
《Journal of Coordination Chemistry》2012,65(16):2910-2918
[Yb2(SBTC)(ox)(H2O)5] n (1) (H4-SBTC?=?5-sulfonyl-1,2,4-benzenetricarboxylic acid and ox?=?oxalate) has been hydrothermally synthesized by reaction of 5-sulfonyl-1,2,4-benzenetricarboxylic acid with Yb(NO3)3?5H2O. In situ formation of oxalate derived from H4-SBTC is unprecedented and adds a new oxalate formation reaction to in situ ligand syntheses. Compound 1 features a 2-D bilayered coordination network, which is further extended into a 3-D supramolecular framework through interlayered hydrogen bonds. Magnetic measurements on 1 indicate that there is an antiferromagnetic interaction between Yb(III) ions. 相似文献
996.
《Journal of Coordination Chemistry》2012,65(16):2600-2609
Synthesis, characterization, and X-ray crystal structure for a mixed-valence binuclear Co(II)/Co(III) complex with the dianionic dithiolate form of a pentadentate ligand 2,6-diacetylpyridinebis(thiosemicarbazone) are reported. A new synthetic methodology has been employed replacing usual cobalt(II) salts by [Co(NH3)5Cl]Cl2 as a precursor. The coordination geometry of cobalt(II), CoN2S2, was found to be distorted tetrahedral, whereas the cobalt(III) coordination sphere, CoN4S2, is slightly distorted octahedral. The magnetic behavior and molar conductivity of the complex are in agreement with the mixed-valence state. 相似文献
997.
《Journal of Coordination Chemistry》2012,65(14):2541-2548
Two metal coordination polymers, {[Zn(bpdc)(bip)]·2H2O}n (1) and [Zn(tdc)(bip)] (2) [H2bpdc?=?biphenyl-4,4’-dicarboxylate, H2tdc?=?thiophene-2,5-dicarboxylate, bip?=?3,5-bis(imidazole-1-yl)pyridine], have been synthesized and characterized by IR, elemental analysis, XRD, and X-ray single-crystal diffraction. In 1, bpdc and bip link Zn(II) ions into a corrugated 2D layer. The corrugated 2D layers polycatenate each other, yielding a 2D→3D polycatenation net. In 2, dinuclear Zn(II) units are formed by bip and further connected by tdc to construct a 2D 3-connected framework. The luminescent properties of 1 and 2 are investigated in the solid state at room temperature. 相似文献
998.
999.
Five new coordination polymers based on a new 2,2'-bipyridine derived ligand N,N'-bis(pyridin-4-yl)-2,2'-bipyridine-5,5'-dicarboxamide (=L) are reported herein. Isostructural three-dimensional coordination polymers with a rare (4,6)-connected network of {4(4).6(2)}(3){4(6).8(9)}(2) topology were synthesised from Cu(NO(3))(2), Zn(NO(3))(2) or a mixture of Cu(NO(3))(2)/Fe(BF(4))(2) with L in complexes {[Cu(5)L(6)]·(NO(3))(10)·(H(2)O)(18)}(∞) (1), {[Zn(5)L(6)]·(NO(3))(10)·(H(2)O)(18)}(∞) (2) and {[Fe(x)Cu(y)L(6)]·(NO(3))(10)·(H(2)O)(18)}(∞) (3; where x+y=5). Complexes with two-dimensional grid structures resulted from treatment with CoCl(2) or Cd(NO(3))(2) with L in complexes {[CoLCl(2)]·DMF}(∞) (4) and {CdL(NO(3))(2)}(∞) (5). 相似文献
1000.
Prof. Dr. Peter Comba Dr. Nina Dovalil Prof. Dr. Lawrence R. Gahan Prof. Dr. Gebhard Haberhauer Prof. Dr. Graeme R. Hanson Dr. Christopher J. Noble Dr. Björn Seibold Dr. Prabha Vadivelu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(9):2578-2590
Two synthetic derivatives of the naturally occurring cyclic pseudooctapeptides patellamide A–F and ascidiacyclamide, that is, H4pat2, H4pat3, as well as their CuII complexes are described. These cyclic peptide derivatives differ from the naturally occurring macrocycles by the variation of the incorporated heterocyclic donor groups and the configuration of the amino acids connecting the heterocycles. The exchange of the oxazoline and thiazole groups by dimethylimidazoles or methyloxazoles leads to more rigid macrocycles, and the changes in the configuration of the side chains leads to significant differences in the folding of the cyclic peptides. These variations allow a detailed study of the various possible structural changes on the chemistry of the CuII complexes formed. The coordination of CuII with these macrocyclic species was monitored by high‐resolution electrospray mass spectrometry (ESI‐MS), spectrophotometric (UV/Vis) and circular dichroic (CD) titrations, and electron paramagnetic resonance (EPR) spectroscopy. Density functional theory (DFT) calculations and molecular mechanics (MM) simulations have been used to model the structures of the CuII complexes and provide a detailed understanding of their geometric preferences and conformational flexibility. This is related to the CuII coordination chemistry and the reactivity of the dinuclear CuII complexes towards CO2 fixation. The variation observed between the natural and various synthetic peptide systems enables conclusions about structure–reactivity correlations, and our results also provide information on why nature might have chosen oxazolines and thiazoles as incorporated heterocycles. 相似文献