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Cu(II)-脱乙酰壳聚糖配位聚合物的配位数 总被引:3,自引:0,他引:3
IR,ESR和XPS的测试结果表明,脱乙酰壳聚糖(简记CS)膜在铜氨水溶液浸渍过程中Cu(II)既与CS发生配位反应形成Cu(II)-CS配位聚合物,也产生吸附作用。ESR谱示出CuCl~2.2H~2O与Cu(II)-CS膜中的Cu(II)均含有一个单电子,可以利用XPS的Shake-up效应研究Cu(II)-CS配位聚合物的配位数,所得结果为4。又以同样的方法研究Cu(II)-聚乙烯醇(简记PVA)配位聚合物的配位数,发现Cu(II)是以低自旋状态的dsp^2杂化空轨道与PVA的羟基氧配位,其配位数也是4,这与资料所报道的一致,从而间接地验证了此方法研究Cu(II)-CS配位聚合物配位数的可靠性。 相似文献
3.
The gas-phase photofragmentation of the mixed-ligand coordination compound trans-bis(trifluoroacetato)bis(N,N'-dimethylethylenediamine)nickel(II) (Ni(tfa)2(dmen)2) detected via time-of-flight mass spectrometry is reported. In contrast to most gas-phase studies of metal-containing compounds where fragmentation of weak metal-ligand bonds dominates, the data here show that the dmen ligands fragment while still coordinated to nickel. The manner in which these ligands fragment is highly specific, leading to mono- and diimine species that remain coordinated to nickel. Uncoordinated mono- and diimine species and various small dmen fragments are also observed with high intensities in the low mass region of the spectra. NiF+, a fragment that is formed by fluorine abstraction, is always observed, even though no Ni-F bonds exist in the starting material. 相似文献
4.
A bimetallic coordination polymer, infinity (2)[{LNi (II)Co (II)}(dca) 2], has been constructed from heterobinuclear [Ni (II)Co (II)] nodes and dicyanamido spacers [L (2-) is the dianion of the Schiff base resulting from the 2:1 condensation of 3-methoxysalicyladehyde with 1,3-propanediamine; L (2-) = N, N'-propylenebis(3-methoxysalycilideneiminato)]. The intranode Co (II)-Ni (II) interaction was found to be ferromagnetic because of the orthogonality of the magnetic orbitals. Below 12 K, the onset of the canted ferromagnetic ordering is observed. 相似文献
5.
Ni(II) N4-macrocycle grafted crown ether: caesium cobalt(III) bis(dicarbollide) coordination polymer
A mixture of a Ni(TMTAA) grafted crown ether and Cs[Co(C2B9H11)2] in toluene-CH2Cl2 affords a 1:1 complex, comprised of layers of infinite two-dimensional polymeric arrays separated by layers of the cobalticarborane anion which themselves form two B-H...Cs+ hydrogen interactions. 相似文献
6.
A new carboxylato-bridged CoII network of formula {Co((kappa1-kappa1)-(kappa1-mu2)-mu4-TDC)(mu2-H2O)0.5(H2O)}n (H2TDC=2,5-thiophenedicarboxylic acid) has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction, thermogravimetric analysis, and IR and UV-visible spectroscopies. The title compound is made of chains of CoII dimers interconnected by TDC2- ligands, showing an unprecedented asymmetric tetradentate coordination mode of the carboxylate functions. Magnetic measurements show weak ferromagnetic interactions between the Co ions within the dimers. 相似文献
7.
Muñoz-Lara FJ Gaspar AB Muñoz MC Arai M Kitagawa S Ohba M Real JA 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(26):8013-8018
All in a spin: A series of three-dimensional porous coordination polymer {Fe(dpe)[Pt(CN)(4)]}?G (dpe = 1,2-di(4-pyridyl)ethylene; G = phenazine, anthracene, or naphthalene) exhibiting spin crossover and host-guest functions is reported. The magnetic properties of the framework are very sensitive to the chemical nature (aromatic or hydroxilic solvents) and the size of the included guest molecules. 相似文献
8.
Oleg A. Levitskiy Yuri K. Grishin Ksenia A. Paseshnichenko Konstantin A. Kochetkov Tatiana V. Magdesieva 《Tetrahedron letters》2018,59(29):2831-2834
One-pot method for direct stereoselective (S)-α-thioalkylation of glycine in Ni(II) coordination environment was elaborated. The reaction of electrochemically deprotonated Ni(II) glycine/Schiff-base complex containing (S)-o-[N-(N′-benzylprolyl)amino]benzophenone as an auxiliary chiral moiety with alkyl thiocyanates leads to the α-thioalkylated derivatives in a practical ca.70% chemical yield and stereoselectivity (de 80%). 相似文献
9.
Shyamapada Shit Joy Chakraborty Anamika Das Glenn P. A. Yap M. S. El. Fallah Samiran Mitra 《Structural chemistry》2007,18(3):317-323
A one-dimensional (1-D) copper(II) coordination polymer [Cu(maleate)(2,2′-bipyridyl)]
n
·2H2O has been synthesised. Single crystal X-ray diffraction study reveals that maleate ion bridges two adjacent copper(II) centres
along the chain in a syn–anti fashion. A complete cryomagnetic investigation of the title complex correlates well with the distorted square pyramidal geometry
of the central copper(II) ion and bridging nature of the maleate. A τ value of 0.26 indicates the distortion towards tbp coordination allowing the magnetic orbital to acquire some character leading to a weak antiferromagnetic interaction having J = −0.26 cm−1. The complex has also been firmly established from several other instrumental techniques like Fourier transform infrared
(FT-IR) and EPR spectroscopies. 相似文献
10.
Peter T. Ndifon Moise O. Agwara Awawou G. Paboudam Divine M. Yufanyi Jean Ngoune Agustín Galindo Eleuterio Álvarez Aminou Mohamadou 《Transition Metal Chemistry》2009,34(7):745-750
A novel one-dimensional zigzag coordination polymer, dinitrodiaqua-bis(hexamethylenetetramine)cobalt(II) was synthesised and
characterised, and the structure was determined by single-crystal X-ray diffraction. The compound has a chain structure with
each cobalt atom covalently bonded to two nitrate ions, two water molecules and two HMTA molecules, giving a slightly distorted
octahedral geometry about the cobalt atom. Each HMTA ligand uses two of its N atoms to bond to two cobalt atoms giving an
approximately bent Co–HMTA–Co configuration. Each chain is hydrogen bonded through OH···N and OH···O interactions with neighbouring
chains leading to an overall polymer structure. Thermal studies show significant mass loss corresponding to the loss of the
coordinated water molecules and the decomposition of both the nitrate ions and the HMTA. 相似文献
11.
《Polyhedron》2007,26(9-11):2047-2053
The reaction of neutral radical ligand 4-(2′-cyanofuryl-5′)-1,2,3,5-dithiadiazolyl with a stoichiometric amount of bis(hexafluoroacetylacetonato)-manganese(II), -cobalt(II) or nickel(II) generates alternating metal-ligand chains in the solid state. The coordination mode of this ligand to the metal dication is unprecedented, providing the first evidence that the nitrogen atoms of a 1,2,3,5-dithiadiazolyl are capable of coordination to a metal dication in the absence of chelation. 相似文献
12.
Baoxia Liu Yankai Huang Xu Zhu Yuanqiang Hao Yujie Ding Wei Wei Qi Wang Peng Qu Maotian Xu 《Analytica chimica acta》2016
Lanthanide coordination polymers (LCPs) have recently emerged as attractive biosensor materials due to their flexible components, high tailorable properties and unique luminescence features. In this work, we designed a smart LCP probe of Tb-CIP/AMP {(CIP, ciprofloxacin) (AMP, adenosine monophosphate)} for Hg2+ detection by using lanthanide ions as metal nodes, CIP as ligand molecule, and AMP as bridging linker and recognition unit. Tb-CIP/AMP emits strong green luminescence due to the inclusion of AMP, which withdraws the coordinated water molecules and shields Tb3+ from the quenching effect of O–H vibration in water molecules. The subsequent addition of Hg2+ into Tb-CIP/AMP can strongly quench the fluorescence because of the specific coordination interaction between AMP and Hg2+. As a kind of Hg2+ nanosensor, the probe exhibited excellent selectivity for Hg2+ and high sensitivity with detection limit of 0.16 nM. In addition, the probe has long fluorescence lifetime up to millisecond and has been applied to detect Hg2+ in drinking water and human urine samples with satisfactory results. We envision that our strategy, in the future, could be extended to the designation of other LCP-based hypersensitive time-gated luminescence assays in biological media and biomedical imaging. 相似文献
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14.
Kensuke Naka Akiko Kobayashi Yoshiki Chujo 《Macromolecular rapid communications》1997,18(12):1025-1032
The star-shaped polymer with trans-tetrapyridyl complex of Ru(II) as a core was prepared by complexation of ester-linked pyridyl-terminated poly(oxyethylene) (M̄n = 2000) with a Ru5Cl122− cluster. The unimodal peak of the star-shaped polymer in the gel-permeation chromatogram was shifted to a higher molecular weight region than that of the starting prepolymer. The electron-withdrawing ester substituent in para position of the pyridine ring shifted the metal-to-ligand charge transfer (MLCT) band into the visible region. 相似文献
15.
Boeckmann J Wriedt M Näther C 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(17):5284-5289
Reaction of FeCl(2)·4H(2)O with KNCSe and pyridine in ethanol leads to the formation of the discrete complex [Fe(NCSe)(2)(pyridine)(4)] (1) in which the Fe(II) cations are coordinated by two N-terminal-bonded selenocyanato anions and four pyridine co-ligands. Thermal treatment of compound 1 enforces the removal of half of the co-ligands leading to the formation of a ligand-deficient (lacking on neutral co-ligands) intermediate of composition [Fe(NCSe)(2)(pyridine)(2)](n) (2) to which we have found no access in the liquid phase. Compound 2 is obtained only as a microcrystalline powder, but it is isotypic to [Cd(NCSe)(2)(pyridine)(2)](n) and therefore, its structure was determined by Rietveld refinement. In its crystal structure the metal cations are coordinated by two pyridine ligands and four selenocyanato anions and are linked into chains by μ-1,3 bridging anionic ligands. Magnetic measurements on compound 1 show only paramagnetic behavior, whereas for compound 2 an unexpected magnetic behavior is found, which to the best of our knowledge was never observed before for a iron(II) homospin compound. In this compound metamagnetism and single-chain magnetic behavior coexist. The metamagnetic transition between the antiferromagnetically ordered phase and a field-induced ferromagnetic phase of the high-spin iron(II) spin carriers is observed at a transition field H(C) of 1300 Oe and the single-chain magnetic behavior is characterized by a blocking temperature T(B), estimated to be about 5 K. 相似文献
16.
A novel one-dimensional ladder-like Cu-Ba compound ([Ba(H2O)3(CuL)2] x 2H2O)n (H3L = Glycylglycine, N-[1-(2-hydroxyphenyl)propylidene]), has been synthesized and structurally characterized; it exhibits ferromagnetic interaction. 相似文献
17.
Two structurally related flexible imidazolyl ligands, bis(N-imidazolyl)methane (L1) and 1,4-bis(N-imidazolyl)butane (L2), were reacted with Cu(II), Co(II) and Ni(II) salts of aliphatic/aromatic dicarboxylic acids resulting in the formation of a number of novel metal–organic coordination architectures, [CuB2(ox)2(L1)2(H2O)2] · 4H2O (1) (ox = oxalate), [Cu(pdc)(L2)1.5] · 4H2O (2, pdc = pyridine-2,6-dicarboxylate), [Co(L)2(H2O)2](tp) · 4H2O (3, tp = terephthalate), [Ni(L1)2(H2O)2](ip) · 5H2O (4, ip = isophthalate), [Cu2(L1)4(H2O)4](tp)2 · 7H2O (5), [Co(mal)(L1)(H2O)] · 0.5MeOH (6, mal = malonate), [Co(pdc)(L1)(H2O)] (7). All the complexes have been structurally characterized by X-ray diffraction analysis. The different coordination modes of the dicarboxylate anions, due to their chain length, rigidity and diimidazolyl functionality, lead to a wide range of different coordination structures. The coordination polymers exhibit 1D single chain, ladder, 2D sheet and 2D network structures. The aliphatic and aromatic dicarboxylates can adopt chelating μ2 and chelating-bridging μ3 coordination modes, or act as uncoordinated counter anions. The central metal ions are coordinated in N2O4, N4O2, N2O3 and N3O3 fashions, depending on the ancillary ligands. The topology of 1 gives rise to macrocycles which are connected through hydrogen bonds to form 1D chains, whereas compound 2 exhibits a 1D polymeric ladder in which the carboxylate acts as a pincer ligand. Compounds 3–5 show doubly bridged 1D chains, and the dicarboxylate groups are not coordinated but form 2D corrugated sheets with water molecules intercalated between the cationic layers. Compound 6 has a 2D network sheet structure in which each metal ion links three neighboring Co atoms by the bis(N-imidazolyl)methane ligand. The cobalt compound 7, with a 2D polymeric double sheet structure, is built from pincer carboxylate (pdc) and 1,4-bis(N-imidazolyl)methane ligands. 相似文献
18.
Liu W Song Y Li Y Zou Y Dang D Ni C Meng Q 《Chemical communications (Cambridge, England)》2004,(20):2348-2349
Self-assembly of metalloligand [CuL](-)(H(3)L =N-5-bromosalicylaldehydeglycyl-l-tyrosine) with Sr(2+) and Na(+) results in a 1D micro(2)-carboxylate- and H(2)O-bridged heterotrimetallic chiral coordination polymer [[Na(CuL)(3)Sr(H(2)O)(3)].9H(2)O]](n), which exhibits weak ferromagnetic exchange interactions and optical activity. 相似文献
19.
Bikshandarkoil R. Srinivasan Santosh Y. Shetgaonkar Pallepogu Raghavaiah 《Journal of Chemical Sciences》2008,120(2):249-257
The aqueous reaction of barium carbonate with 2-nitrobenzoic acid (2-nbaH) results in the formation of a one-dimensional coordination
polymer, catena-poly[[hexa(aqua)dibarium(II)]bis[(μ
2-2-nitrobenzoate-O,O,O-NO2)(μ
2-2-nitrobenzoate-O,O,O′)]] 1. On heating at 100°C compound 1 is dehydrated to anhydrous barium bis(2-nitrobenzoate) 2. The anhydrous compound can be re-hydrated to 1 on exposure to water vapour. Compounds 1 and 2 were characterized by elemental analysis, IR and UV-Vis spectra, DSC thermograms, weight loss studies and the structure of
1 was determined. 1 and 2 can be thermally decomposed to BaCO3 by heating at 800°C. The polymer [[Ba(H2O)3]2(μ
2-2-nba-O,O,O-NO2)2 (μ
2-2-nba-O,O,O′)2]
n
1 crystallizes in the centrosymmetric triclinic space group Pī and all atoms are located in general positions. The polymeric
structure is based on a dimeric unit and consists of three water molecules coordinated to a central Ba(II) and two unique
2-nitrobenzoate (2-nba) anions, one of which (μ
2-2-nba-O,O,O-NO2) functions as a tridentate ligand and is linked to a Ba(II) through the oxygen atom of the-NO2 group and forms a monoatomic μ
2-carboxylate bridge between two symmetry related Ba(II) ions with a Ba···Ba distance of 4·5726(14) ?. The second unique 2-nba
anion (μ
2-2-nba-O,O,O′) also functions as a tridentate ligand with the carboxylate oxygen atoms linked to a Ba(II) ion in a bidentate
fashion and one of the carboxylate oxygen atoms forming a monoatomic bridge between two symmetry related Ba(II) ions resulting
in a Ba···Ba separation of 4·5406(15) ?. These differing tridentate 2-nba ligands link {Ba(H2O)3} units into a one-dimensional polymeric chain extending along b axis. In the infinite chain each nine coordinated Ba(II) is bonded to three water molecules and further linked to six oxygen
atoms of four different 2-nitrobenzoate anions with alternating pairs of Ba(II) ions in the chain bridged by a pair of (μ
2-2-nba-O,O,O-NO2) and (μ
2-2-nba-O,O,O′) ligands resulting in alternating Ba···Ba distances of 4·5406(15) and 4·5726(14) ? across the chain.
Dedicated to Prof. S. K. Paknikar on the occasion of his 73rd birthday. 相似文献
20.
Branscombe ND Atkins AJ Marin-Becerra A McInnes EJ Mabbs FE McMaster J Schröder M 《Chemical communications (Cambridge, England)》2003,(9):1098-1099
Multi-frequency EPR spectroscopy on 61Ni-labelled samples of [Ni2(L)]3+ confirms extensive charge-delocalisation between the Ni(III) centre and thiolate donors in the Ni(II)Ni(III) complex. 相似文献