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161.
The malonato-bridged copper(II) complex [Cu(mal)(H2O)(azpy)1/2] · H2O (1) (mal = malonate, azpy = 4,4′-azobispyridine) has been synthesized and characterized by X-ray diffraction. The structure of 1 consists of malonato-bridged uniform copper(II) chains which are covalent connected through azpy to form two-dimensional wavelike network. The magnetic pathway of complex 1 is through a single syn-anti carboxylate bridge connecting equatorial and equatorial positions of adjacent copper(II) atoms, and have the value of the intrachain ferromagnetic coupling (J = 8.73(3) cm−1) and interchain antiferromagnetic coupling (zJ′ = − 1.31(1) cm−1) through a numerical expression for a ferromagnetic uniform chain. 相似文献
162.
Shi-bin Wang Dai-zheng Liao Zong-hui Jiang Shi-ping Yan 《Inorganica chimica acta》2005,358(9):2595-2601
Based on the complex ligand (CuL H2L = 2,3-dioxo-5,6:15,16-dibenzo-1,4,8,13-tetraazacyclotetradeca-7,13-diene), which includes macrocyclic oxamido bridge, three trinuclear complexes were prepared. They are of the formula [(CuL)2M(ClO4)2] (M = Co(1), Ni(2)) and [(CuL)2Zn(CH3OH)2] · (ClO4)2 (3). The crystal structures of the three complexes have been determined and the M(II) of the three complexes all exist on the mirror plane. Complex 1 is the first Cu-Co complex bridged by oxamido. Their magnetic properties were studied by susceptibility versus temperature measurement, the best fitting of the experimental data led to J = −28.12 cm−1 for 1, J = −42.88 cm−1 for 2, and J = −2.13 cm−1 for 3. 相似文献
163.
R.?Fernández-Pacheco M.?R.?IbarraEmail author J.?G.?Valdivia C.?Marquina D.?Serrate M.?S.?Romero M.?Gutiérrez J.?Arbiol 《NanoBioTechnology》2005,1(3):300-303
Bioferrofluids obtained from carbon coated iron nanoparticles are promising candidates for magnetic drug delivery. The carbon
cages render the particles biocompatible, and provide a good support for drug adsorption. We propose a method in which gold
plated permanent magnets are implanted directly in the affected organ, close to the tumour, by endoscopic techniques. The
bioferrofluid charged with the chemotherapeutic agent is injected and the particles attracted to the magnet, then desorption
of the drug takes place at the tumoral region. This method seems to be more promising, costless and effective than that based
on the application of external magnetic fields. Preliminary results of drug adsorption and a preclinical experimental animal
model are described. 相似文献
164.
Miguel A. Novak Marcus V. de Rangel e Silva Maria G.F. Vaz Solange M.S.V. Wardell 《Inorganica chimica acta》2005,358(4):941-946
The pale blue title compound, 4, was obtained from the reaction between 1,7,11,17-tetraaza-2,6,12,16-tetraoxacycloeicosane, Ni(acac)2 and NaBPh4 in aqueous acetone. X-ray structure determination at 120 K revealed that the dication of the ionic complex, 4, contains two independent octahedral NiII centres with trans-Ni2N2O4 chromophores. The macrocyclic ligand and an aqua ligand act as bridges to the two nickel centres: the Ni-O(aquo)-N bond angle is 137.65(17)°. Each Ni centre is bonded to two nitrogens of the macrocycle, to a chelating acac unit, to an ethanol molecule as well as the bridging oxygen of the aqua group. The two nickel atoms sit outside the macrocycle cavity, such that the macrocyclic ligand acts as a canopy for the remainder of the dication. While none of the macrocycle oxygens are involved in the coordination to Ni, they are involved in internal hydrogen bonding with the aqua and ethanol ligands. Magnetic measurements show a paramagnetic behaviour down to 2 K, with an effective moment of 2.8 Bohr magnetons at room temperature. 相似文献
165.
Saposin C (Sap C) is known to stimulate the catalytic activity of the lysosomal enzyme glucosylceramidase (GCase) that facilitates the hydrolysis of glucosylceramide to ceramide and glucose. Both Sap C and acidic phospholipids are required for full activity of GCase. In order to better understand this interaction, mixed bilayer samples prepared from dioleoylphosphatidylglycerol (DOPG) and dioleoylphosphatidylserine (DOPS) (5:3 ratio) and Sap C were investigated using 2H and 31P solid-state NMR spectroscopy at temperatures ranging from 25 to 50 °C at pH 4.7. The Sap C concentrations used to carry out these experiments were 0 mol%, 1 mol% and 3 mol% with respect to the phospholipids. The molecular order parameters (SCD) were calculated from the dePaked 2H solid-state NMR spectra of Distearoyl-d70-phosphatidylglycerol (DSPG-d70) incorporated with DOPG and DOPS binary mixed bilayers. The SCD profiles indicate that the addition of Sap C to the negatively charged phospholipids is concentration dependent. SCD profiles of 1 mol% of the Sap C protein show only a very slight decrease in the acyl chain order. However, the SCD profiles of the 3 mol% of Sap C protein indicate that the interaction is predominantly increasing the disorder in the first half of the acyl chain near the head group (C1-C8) indicating that the amino and the carboxyl termini of Sap C are not inserting deep into the DOPG and DOPS mixed bilayers. The 31P solid-state NMR spectra show that the chemical shift anisotropy (CSA) for both phospholipids decrease and the spectral broadening increases upon addition of Sap C to the mixed bilayers. The data indicate that Sap C interacts similarly with the head groups of both acidic phospholipids and that Sap C has no preference to DOPS over DOPG. Moreover, our solid-state NMR spectroscopic data agree with the structural model previously proposed in the literature [X. Qi, G.A. Grabowski, Differential membrane interactions of saposins A and C. Implication for the functional specificity, J. Biol. Chem. 276 (2001) 27010-27017] [1]. 相似文献
166.
A preparation of thiophilic agarose-based paramagnetic particles (T-Gel) has been developed with physical characteristics (particle size and particle density) that facilitate its use as a batch separation medium suitable for the large-scale purification and isolation of immunoglobulins. The medium was used to extract immunoglobulins from a wide range of starting materials, including sera, ascites fluid, tissue culture medium, and whole blood. None of these starting materials required pretreatment such as clarification by centrifugation or filtration prior to antibody extraction. The antibody purity obtained using T-Gel compared well with that obtained using protein A agarose column chromatography. Yields were approximately 30 mg of immunoglobulins per milliliter of T-Gel, and little was required in the way of specialist equipment. The method is uncomplicated and involves a roll mix extraction overnight, followed by magnetic separation to facilitate supernatant removal and subsequent washing of the particles. Elution of bound antibodies was carried out at neutral pH to yield a concentration of immunoglobulins that was approximately 7 mg/ml. The method was found to be applicable to antibody purification from the blood serum of seven different mammalian species and for all immunoglobulin classes. 相似文献
167.
Svetlana G. Baca Irina G. Filippova Maria Gdaniec Nicolae V. Gerbeleu Reto Basler 《Inorganica chimica acta》2004,357(12):3419-3429
Three new coordination polymers [M(Pht)(1-MeIm)2]n (where M=Cu (1), Zn (2), Co (3); Pht2−=dianion of o-phthalic acid; 1-MeIm=1-methylimidazole) and two compounds [M(1-MeIm)6](HPht)2 · 2H2O (M=Co (4), Ni (5)) have been synthesized and characterized by X-ray crystallography. The structures of 1-3 (2 is isostructural to 3) consist of [M(1-MeIm)2] building units connected by 1,6-bridging phthalate ions to form infinite chains. In complex 1, each copper(II) center adopts a square coordination mode of N2O2 type by two O atoms from different phthalate ions and two N atoms of 1-MeIm, whereas in 3 two independent metal atoms are tetrahedrally (N2O2) coordinated to a pair of Pht ligands and a pair of 1-MeIm molecules. There are only van der Waals interactions between the chains in 1, while the three-dimensional network in 3 is assembled by C-H?O contacts. In contrast to polymers 1-3 the structures of 4 and 5 (complexes are also isostructural) are made up of the [M(1-MeIm)6]2+ cation, two hydrogen phthalate anions (HPht−) and two H2O solvate molecules. The coordination around each metal(II) atom is octahedral with six nitrogen atoms of 1-MeIm. Extended hydrogen bonding networks embracing the solvate water molecules and a phthalate residue as well as the weak C-H?O interactions stabilize the three-dimensional structures. Magnetic studies clearly show that the magnetic ions do not interact with each other. Furthermore, in compound 4 we have another example of a highly anisotropic Co2+ ion with a rhombic g-tensor and large zero-field-splitting. The complexes were also characterized by IR and 1H NMR spectroscopy, thermogravimetric analysis, and all data are discussed in the terms of known structures. 相似文献
168.
Antonis Vlachos Catherine P Raptopoulou Yiannis Sanakis Georgios Diamantopoulos Marina Karayanni Aris Terzis 《Inorganica chimica acta》2004,357(11):3162-3172
Complex [Cr3O(O2CPh)6(MeOH)3](NO3) · 2MeOH (1 · 2MeOH) has been synthesized from the one-pot reaction between Cr(NO3)3 · 9H2O and NaO2CPh in MeOH. The structure of the complex has been solved by single-crystal X-ray crystallography. It crystallizes in the monoclinic space group P21/n with a=14.716(6) Å, b=22.569(8) Å, c=15.755(6) Å, β=95.02(1)°, V=5212.5(4) Å3 and Z=4. Although the cation does not possess any crystallographically imposed symmetry element, its {Cr3(μ3-O)} core is nearly symmetric. Each CrIII…CrIII vector is further bridged by two η1:η1:μ2 benzoates, with a terminal MeOH molecule completing octahedral coordination at each metal ion. The crystal structure consists of layers that are parallel to (0 1 0) crystallographic plane and are formed through π-π stacking interactions and hydrogen bonds. Variable-temperature magnetic susceptibility and solid-state 1H NMR studies indicate that the total spin value of the ground state is 1/2. EPR experiments reveal the existence of a distribution of trimers with axial anisotropy in the g tensor. 相似文献
169.
A new bis(macrocycle) ligand, 7,7′-(2-hydoxypropane-1,3-diyl)-bis{3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),13,15-triene} (HL), and its dicopper(II) ([Cu2(HL)Cl2](NO3)2 · 4H2O (4a), [Cu2(HL)I2]I2 · H2O (4b)) and dinickel(II) ([Ni2(L)(OH2)](ClO4)3 (5a), [Ni2(L)(OH2)]I3 · 2H2O (5b), [Ni2(L)N3](N3)2 · 7H2O (5c)) complexes have been synthesized. The alkoxide bridged face-to-face structure of the dinickel(II) complex 5c has been revealed by X-ray crystallography, as well as the “half-opened clamshell” form of the bis(macrocyclic) dicopper(II) complex 4b. Variable temperature magnetic susceptibility studies have indicated that there exists intramolecular antiferromagnetic coupling (J=−33.8 cm−1 (5a), −32.5 cm−1 (5b), and −29.7 cm−1 (5c)) between the two nickel(II) ions in the nickel(II) complexes. 相似文献
170.
Hironori Kanda Yuko Hosokoshi Satoshi Kawata Katsuya Inoue 《Inorganica chimica acta》2004,357(11):3125-3133
A reaction of Cu(II) nitrate and 4,4,5,5-tetramethyl-2-(2-hydroxophenyl)imidazolin-1-oxyl (IM2PhOH) with potassium methoxide in methanol gave a homoleptic bis(imino nitroxide) complex of [Cu(IM2PhO)2] (1). The single-crystal X-ray analysis of 1 showed that the imino nitroxide anion, IM2PhO−, chelated to a CuII ion via an imino-N and a phenoxide-O atoms to form a six-membered chelate ring. The coordination geometry around the Cu(II) ion was a distorted square-planar polygon; the dihedral angle between the two coordination planes, each of which was defined by Cu and two ligating atoms of IM2PhO−, was 40.81°. The temperature dependences of the magnetic susceptibility and the EPR spectra of 1 indicate that the magnetic interaction between Cu(II) and the imino nitroxide is ferromagnetic, while there is a moderate antiferromagnetic interaction between two coordinated imino nitroxides. A balance between these opposite interactions attains the lowest molecular doublet spin-state in 1. The variable temperature magnetic circular dichroism (MCD) spectrum of the complex 1 also showed two negative components with a large C term, which may be due to the charge-transfer (CT) transition originated from the d orbital to the SOMO π* orbital in the spin-coupled IM2PhO− radicals; resulting in the largely split doublet excited states with the spin singlet and triplet d8 configurations. 相似文献