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51.
A potentially heptadentate ligand H3L (N,N′-bis(2-hydroxybenzyl)-1,3-bis[(2-aminoethyl)amino]-2-propanol) and its two Ni(II) complexes, [Ni(H2L)H2O](H2O)3ClO4 (1) and [Ni(H2L)(H2O)](H2O)Cl (2) were prepared and characterized. X-ray structural analyses indicate that complex 1 has a distorted octahedral coordination geometry, with four amine N atoms of H2L− defining the equatorial plane, one aqua O atom and one phenoxo O atom of the ligand occupying two axial positions, respectively. The Ni(II) center of 2 has coordination geometry similar to that of 1. IR and electronic spectra of 1 and 2 are in agreement with their crystal structural features. Approximately along the ab plane, 2D supramolecular structure of 1 is assembled through multiple hydrogen bonds between hydroxy groups of the ligands, coordinated and crystal lattice H2O and π-π stacking interactions between adjacent phenyl rings of the ligands, while for that of 2, probably along the a axis, 1D chain structure is also formed by multiple hydrogen bonds, but lack of π-π stacking interactions. 相似文献
52.
M. Carla Aragoni Francesco Demartin Alessandra Garau Vito Lippolis Silvia Rizzato 《Inorganica chimica acta》2004,357(12):3803-3809
The compounds [Ni(L)(MeCN)]I8 (1) and [Ni(L)(MeCN)]I12 (2) have been obtained from the reactions of the complexes [Ni(L)(L′)][BF4](2 + n) {L=2,5,8-trithia[9](2,9)-1,10-phenanthrolinophane; L′=MeCN, Cl−, Br−, I−; n=charge of L′} with an excess of I2 (molar ratios of 6, 10 and 20 have been used), in the presence of the stoichiometric amount of I− (as Bu4nNI) necessary to balance the charge of the complex cation [Ni(L)(L′)](2 + n)+. An X-ray diffraction analysis shows that, independently of the nature of L′, both 1 and 2 contain the complex cation [Ni(L)(MeCN)]2+, which is therefore capable of templating two different polyiodide networks based on interacting I3−/I5− and I5−/I7 units, respectively. The solid state FT-Raman spectra of 1 and 2 are discussed based on their structural features. 相似文献
53.
F. Moro F. Piga I. Krivokapic A. Burgess W. Lewis J. McMaster J. van Slageren 《Inorganica chimica acta》2010,363(15):4329-4336
A study of the magnetic anisotropies of three Ni cubane single-molecule magnets (SMM), [Ni(hmp)(MeOH)Cl]4·H2O (1·H2O) (hmpH = (2-hydroxymethyl)pyridine) [Ni(hmp)(dmb)Cl]4 (2) (dmb = 3,3-dimethylbutanol) and [Ni(hmp)(dmp)Cl]4 (3) (dmp = 2,2-dimethylpropanol) is reported. Frequency domain magnetic resonance spectroscopic (FDMRS) studies on 1, 2 and 3 as powder pellets reveal zero-field splitting (ZFS) for the spin ground states of these compounds in the solid state. The ZFS of the complexes 1 and 2 were determined and the presence of different molecular species was found in both complexes while only one species was found in 3. The nesting of the variable temperature variable field (VTVH) curves observed from magnetic circular dichroism (MCD) measurements on 1 in solution confirms the presence of ZFS. Virtually all the bands observed in the magnetic circular dichroism spectra possess the same sign, which may be related to the ferromagnetic exchange coupling. In addition, MCD measurements of a dilute solution demonstrate the molecular origin of the magnetic anisotropy in 1. 相似文献
54.
55.
Tuszyńska S 《The New phytologist》2006,169(4):819-828
Organelles of ectomycorrhizal fungi are known to respond to changes in the extracellular environment. The response of vacuoles, mitochondria and microtubules to short-term nickel (Ni2+) exposure were investigated in hyphal tip cells of a Paxillus involutus from a heavy metal-rich soil. Vacuoles, mitochondria and microtubules were labelled with Oregon Green 488 carboxylic acid diacetate, 3,3'-dihexyloxacarbocyanine iodide (DiOC6(3)) and anti-alpha-tubulin antibodies, respectively; hyphae were treated with NiSO4 in the range of 0-1 mmol l(-1) and examined microscopically. Untreated hyphal tip cells contained tubular vacuole and mitochondrial networks. Ni2+ caused loss of organelle tubularity and severe microtubule disruption that were exposure-time and concentration dependent. Fine tubular vacuoles thickened and eventually became spherical in some hyphae, tubular mitochondria fragmented and microtubules shortened and aggregated into patches in most hyphae. Tubular vacuoles reformed on NiSO4 removal and tubular mitochondria in the presence of NiSO4 suggesting cellular detoxification. These results demonstrate that Ni2+ induces changes in organelle and microtubule morphology. Recovery of tubular organelles to pretreatment morphology after Ni2+ exposure suggests cellular detoxification of the metal ion. 相似文献
56.
Nickel(II) complexes of N,N′-dimethyl-N,N′-bis(pyridyl-2yl-methyl)ethylene-diamine (L1), N,N′-dimethyl-N,N′-bis(pyridyl-2-ylmethyl)-1,2-diaminopropane (L2) and N,N′-dimethyl-N,N′-bis(pyridyl-2-ylmethyl)-1,3-diaminopropane (L3) were prepared and their spectroscopic and redox properties studied. The distorted octahedral structure was determined for [NiL3ClCH3OH](ClO4) by using X-ray crystallography. The electronic spectral behavior of the complexes at different pHs was analyzed; it is shown that a new band grew at the expense of the other band intensity in acid media. The redox properties of ligands and their complexes show the peaks of Ni(II) → Ni(III) and Ni(II) → Ni(0) as these were detected at low concentration while Ni(II) → Ni(I) process was detectable clearly at high concentration. Furthermore, the interaction studies of 2-mercaptoethanesulfonic acid as a simulator of coenzyme M reductase (CoM) with NiN4 chromophores are discussed. 相似文献
57.
Using the precursor compound 3,4:10,11-dibenzo-1,13[N,N′-bis{(3-formyl-2-hydroxy-5-methyl)benzyl}diaza]-5,9-dioxocyclopentadecane, a series of macrobicyclic heterobinuclear Ni(II)Zn(II) complexes have been synthesized from the corresponding mononuclear nickel(II) complexes via a template method by Schiff’s base condensation. Electrochemical and kinetic studies of the complexes have been carried out on the basis of macrocyclic ring size. Cyclic voltammetry and controlled electrolysis studies indicate that the nickel(II) metal ion in the heterobinuclear complexes undergo quasireversible one electron reduction and oxidation, whereas the zinc(II) metal ion does not undergo any reduction and oxidation. All the heterobinuclear Ni(II)Zn(II) complexes are ESR inactive and diamagnetic in nature. The kinetics of hydrolysis of 4-nitrophenyl phosphate explores that the catalytic activities of the complexes are found to increase with macrocyclic ring size of the complexes. As the macrocyclic ring size increases, the spectral, electrochemical and catalytic studies of the complexes show variation due to distortion in the geometry of metal centre. 相似文献
58.
Three group 10 complexes containing nido-carborane diphosphine, [NiCl(PPh3){7,8-(PPh2)2-7,8-C2B9H10}] (1), [PdCl(PPh3){7,8-(PPh2)2-7,8-C2B9H10}] · 1.25CH2Cl2 (2) and [PtCl(PPh3){7,8-(PPh2)2-7,8-C2B9H10}] · 2.5CH2Cl2 (3) have been synthesized by the reactions of [M(PPh3)2Cl2] (M = Ni, Pd, Pt) with closo carborane diphosphine 1,2-(PPh2)2-1,2-C2B10H10 in ethanol. For complex 3, it could also be obtained under solvothermal condition. All three complexes were characterized by elemental analysis, FT-IR, 1H and 13C NMR spectroscopy and X-ray structure determination. Single crystal structures show that their structures are similar to each other. In each complex, the nido [7,8-(PPh2)2-7,8-C2B9H10]−, which resulted from the degradation of the initial closo ligand 1,2-(PPh2)2-1,2-C2B10H10 during the reaction process, was coordinated bidentately through the P atoms to M(II) ion, and this resulted in a stable five-membered chelating ring between the bis-diphosphine ligand and the metal. The coordination mode of the metal can be described as a slightly distorted square-planar, in which the remaining two positions were occupied by one Cl− and one PPh3 group. 相似文献
59.
V.V. Saraev P.B. Kraikivskii D.A. Matveev K. Lammertsma 《Inorganica chimica acta》2006,359(7):2314-2320
The oxidation of Ni(PPh3)4 with BF3 · OEt2, H3CCOOH, and F3CCOOH, and that of (PPh3)2Ni(C2H4) with BF3 · OEt2 is studied by EPR spectroscopy. The reaction of the Ni(0) complexes with BF3 · OEt2 gives Ni(II) complexes with which they react to form Ni(I) compounds with covalent Ni-F and Ni-B bonds that transform with excess BF3 · OEt2 into cationic paramagnetic Ni(I) complexes. Acetic acid also adds oxidatively to Ni(PPh3)4 to form a Ni(II) complex that reacts further to give Ni(I) hydride and carboxylate complexes. The Ni(I) hydride is transformed by the acid into the Ni(I) carboxylate with release of hydrogen, the amount of which depends on the rate of acid addition. The following Ni(I) complexes are identified in the reaction medium: [Ni(PPh3)3]BF4, [(PPh3)2Ni(OEt2)]BF4, [(PPh3)Ni(OEt2)n]BF4, (PPh3)2NiBF2, (PPh3)3NiOOCCH3, and [(PPh3)2Ni(OEt2)P(OEt)3]BF4. Oxidation schemes of Ni(0) complexes by Lewis and Brønsted acids are given. 相似文献
60.
One barrier to the construction of nanoscale devices is the ability to place materials into 2D- and 3D-ordered arrays by controlling the assembly and ordering of connections between nanomaterials. Ordered assembly of nanoscale materials may potentially be achieved using biological tools that direct specific connections between individual components. Recently, viruses were successfully employed as scaffolds for the nucleation of nanoparticles and nanowires (Mao et al., 2004); however, there is a paucity of methods for the higher order assembly of phage-templated materials. Here we describe a general strategy for the assembly of filamentous bacteriophages into long, wire-like or into tripod-like structures. To prepare the linear phage assemblies, dimeric leucine zipper protein domains, fused to the p3 and p9 proteins of M13 bacteriophage, were employed to direct the specific end-to-end self-association of the bacteriophage particles. Electron microscopy revealed that up to 90% of the phage displaying complementary leucine zipper domains formed linear multi-phage assemblies, composed of up to 30 phage in length. To prepare tripod-like assemblies, phage were engineered to express trimeric leucine zippers as p3 fusion proteins. This resulted in 3D assembly with three individual phages attached at a single point. These ordered phage structures should provide a foundation for self-assembly of virally templated nanomaterials into useful devices. 相似文献