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1.
A hydrated tetra-carboxylato-bridged dinuclear copper(Ⅱ) complex [Cu2(mEP)2(H2O)2]2 (1) (mEp is mono -ethyl phthalate or 1,2-benzenedicarboxylate monoethyl ester) has been prepared and characterized by X-ray diffraction single crystal structure analysis and magnetic measurements. This dinuclear complex adopts dimeric paddle-wheel cage structure and the coordination model around each copper(Ⅱ) atom is square-pyramidal with four oxygen atoms of the carboxylate groups from four different mono-ethyl phthalate ligands and one oxygen atom of water as apical position. The magnetic data for 1 exhibited strong intramolecular antiferromagnetic interaction between the two paramagnetic metal ions with 2J=-315.18 cm-1. Comparing with other related complexes in structure and magnetic propertity, the main factor which determines the strong antiferromagnetic interaction in the dimeric copper(Ⅱ) carboxylates is the electronic structure of the bridging O-C-O moiety. CCDC: 624561.  相似文献   

2.
Three binuclear Nickel(Ⅱ) complexes were synthesized, bridged with dithiooxalate, Ni2(Bpy)3(Dto)2(H2O)3(1), Ni2(Phen)3(Dto)2(H2O)3(2) and Ni2(Me2Bpy)3(Dto)2(H2O)2 (3) (Bpy=2,2′-Bipyridine, Phen=1,10-phenanthroline, Me2Bpy=4,4′-dimethyl-2,2′-bipyridine, Dto2-=Dithiooxalate), and characterized by elemental analyses, IR, UV-Visible spectra, conductance. The variable temperature magnetic susceptibilities for the complexes were measured in the range of temperature between 1.5 K and 298 K. Experimental data of magnetic susceptibility were successfully fit to theoretical value based on the spin Hamiltonian operator:(?), S1=S2=1, giving the magnetic exchange parameters of 2J=-52.8 cm-1. This result indicates the presence of a strong antiferromagnetic spin exchange interaction between the Ni(Ⅱ) ions. The magnetic exchange parameters of the binuclear Nickel(Ⅱ) complexes bridged with dithiooxalate is larger than that of the binuclear Nickel(Ⅱ) complexes bridged with oxalate. Dithiooxalate is more effective to transfer antiferromagnetic spin exchange interaction between the Ni(Ⅱ) ions than oxalate.  相似文献   

3.
Two new binuclear Fe(Ⅲ)-Fe(Ⅲ) and Mn(Ⅱ)-Mn(Ⅱ) complexes containing the dianions of chloranilic acids (CA) which act as bridging ligand in the complexes, have been synthesized namely [Fe2(phen)4(u-CA)](ClO4)4·2H2O and [Mn2(phen)4(u-CA)](ClO4)2·3H2O (phen = O-phenanthroline; CA = dianions of chloranilic acids). They have been characterized by elemental analyses, IR, electronic spectra, susceptibility and variable-temperature magnetic susceptibility. The results indicate that there is a antiferromagnetic interaction between metal ions in the complexes at low temperature. The observed data were well fitted to those from a Heisenberg model. The obtained parameters: J= -2.02cm-1, g = 2.25 for Fe(Ⅲ)-Fe(Ⅲ) complex; J=-5.45cm-1, g = 2.01 for Mn(Ⅱ)-Mn(Ⅱ) complex.  相似文献   

4.
Two Trinuclear copper(Ⅱ) complexes bridged with N,N′-Bis(2-pyridylethyl)-Dithiooxamidate, [Cu3L2](ClO4)2 (1) and [Cu3L2](NO3)2 (2) (H2L=N,N′-Bis(2-pyridylethyl)-Dithiooxamide), have been synthesized, and characterized by elemental analyses, IR, UV-Visible spectra, conductance and EPR spectra. The variable temperature magnetic susceptibility for complex 1 has been measured in the temperature range of 1.5~298 K. Experimental data of magnetic susceptibility are successfully fit to theoretical value based on the spin Hamiltonian operator:(?), S1=S2=S3=1/2, giving the magnetic exchange parameters of 2J=-221.6 cm-1 and 2j=-15.8 cm-1. This result indicates the presence of a strong antiferromagnetic spin exchange interaction between the Cu(Ⅱ) ions.  相似文献   

5.
The manganese(Ⅲ) complex [Mn(acacen){N(CN)2}]n [H2acacen=bis(acetylacetone)ethylenediimine] has been synthesized and the structure has been determined. The complex forms a one-dimensional chain structure via the bidentate bridge ligand μ1,5-[N(CN)2]- linking [Mn(acacen)] moiety. The magnetic property of the compound (75~300 K) shows the existence of an antiferromagnetic exchange interaction among paramagnetic centers along the chain. CCDC: 244940.  相似文献   

6.
锌(Ⅱ)-氨基酸水杨醛席夫碱-α-氨基酸三元配合物的稳定性   总被引:10,自引:1,他引:9  
The stability constants of binary complexes of Zn(Ⅱ)-α-amino acid and ternary complexes of Zn(Ⅱ)-N-Salicylideneaminio acid (ligand A)-α-amino acid(ligand B) at (25±0.1)℃ and in the presence of 0.1 mol·L-1 KNO3 have been determined by pH method. The α-amino acid(Aa) used were Glycine(Gly), L-Serine(Ser), L-Leucine(Leu), L-Proline(Pro) and L-Phenylalanine(Phe). It was found that the linear free energy relationship (LFER) exists nicely between the following parameter pairs logβ102 and pKB2, logβ111 and pKB2, and logβ111 and pKA2. The ΔlgK was used to characterize the stability of ternary complexes related to the stability of parent binary complexes. The hydrophobic interaction between ligands in the ternary complexes was studied.  相似文献   

7.
A Schiff base ligand 4-[indol-3-yl]-but-3-en-2-one benzoyl hydrazone (HL), and its four transition metal complexes (ML2,M=Cu(Ⅱ), Ni(Ⅱ), Zn(Ⅱ) and Co(Ⅱ)) have been prepared and characterized by means of elemental analysis, EI-MS, molar conductivity, IR, UV-Vis and 1H NMR. The results showed that HL as a bidentate ligand coordinated with transition metal ions to form four-coordination complexes. The antibacterial activity was studied by using the filter scraps diffusion method, and the results indicated that the ligand and the complexes had a low bacteriostatic activity against S. Aureu, P. Aeruginosa and E. Coli. The low in vitro antitumor activity of the title complexes was also observed by using MTT method against KB, A2780, Bel7402 and HELF.  相似文献   

8.
The effect of Ni substitution for Mn on magnetic and transport properties has been investigated for layered manganese oxides LaSr2Mn2-xNixO7. Nickel doping hampered the canted antiferromagnetic (AFM) exchange at low temperature and their Neel temperature (TN) decreased from 138 K (x=0) to 102 K (x=0.3). Meanwhile, spin glass, charge ordering and metal-insulator transition are suppressed by Ni addition. The resistivity increases obviously with increasing x due to double exchange interaction channel broken by Ni2+ addition. The resistivity of all samples in low temperature range fits to the Mott′s variable rang hopping (VRH) model, while it fits to nearest neighbor hopping of small polarons model in high temperature range.  相似文献   

9.
Two new trinuclear copper(Ⅱ) complexes bridged with N,N′-Bis(2-pyridylmethyl)-Dithiooxamidate, [Cu3L2](ClO4)2(1) and [Cu3L2](NO3)2(2) (H2L=N,N′-Bis(2-pyridylmethyl)-Dithiooxamide), have been synthesized, and characterized by elemental analyses, IR, UV-visible spectra, conductance and EPR spectra. The variable temperature magnetic susceptibility for complex (1) has been measured in the range of 1.5~298K. Experimental data of magnetic susceptibility are successfully fit to theoretical value based on the spin Hamiltonian operator: H=-2J(S1S2+S2S3)-2JS1S3, S1=S2=S3=1/2, giving the magnetic exchange parameters of 2J=-170 cm-1 and 2J′=-7.2 cm-1. This result indicates the presence of a strong antiferromagnetic spin exchange interaction between the Cu(Ⅱ) ions.  相似文献   

10.
纳米Mn-Zn铁氧体的制备和研究   总被引:10,自引:0,他引:10  
Nanosize manganese zinc ferrites were fabricated by hydrothermal precipitation route using Fe2(SO4)3, ZnSO4·7H2O, MnSO4·H2O as material, then some calcinated at 500 ℃ and studied by XRD, TEM, IR and VSM. The results showed that the products were spinel crystal structure and uniformly sized nanoparticles (15~25 nm) with little aggregation. The analysis of IR showed that the superficial water can be eliminated, but that was embedded in crystal lattice can not be removed by calcinating. The effect Zn content x on the lattice (a) of nanosize Mn1-xZnxFe2O4 was also discussed. The lattice of nanosize Mn1-xZnxFe2O4 decreases with x increasing; and its value deviated the standard lattice (a0) of normal size manganese zinc ferrites. A lot of water was absorbed during the hydrothermal process owing to the large surface of nanosize particles. The change of magnetic properties of MnxZn1-xFe2O4 with x increasing was studied: nanosize MnxZn1-xFe2O4 particles synthesized by us exhibited peculiar magnetic properties curve with Zn content (x) increasing, Superparamagnetic behaviors of the synthesized ZnFe2O4 samples were confirmed by magnetic characterization, which can be explained by the difference between the distribution of the metal ions (Mn2+, Zn2+ and Fe3+) among the tetrahedral (A) and the octahedral (B) sites of nanosize ferrite and that of bulk ferrite.  相似文献   

11.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

12.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

13.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

14.
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.  相似文献   

15.
In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.  相似文献   

16.
Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.  相似文献   

17.
用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.  相似文献   

18.
19.
A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu0 as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than CuI in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).  相似文献   

20.
(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C60, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.  相似文献   

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