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1.
Weizhen Zhao Jiangang Yu Shengju Song Wenhong Yang Hao Liu Xiang Hao Carl Redshaw Wen-Hua Sun 《Polymer》2012,53(1):130-137
The ligand series 2-[1-(2,4-dibenzhydryl-6-methylphenylimino)ethyl]-6-[1-(arylimino)ethyl]pyridines and the iron(II) chloride complexes thereof have been synthesized and characterized by elemental and spectroscopic analyses. The molecular structures of C1 and C2, determined by single-crystal X-ray diffraction analysis, confirmed a pseudo-square-pyramidal geometry at the iron center. Upon treatment with either MAO or MMAO, all iron pre-catalysts possessed good thermo-stability and exhibited high activities [up to 5.22 × 107 g mol?1(Fe) h?1] toward ethylene polymerization, producing highly linear polyethylene products. Optimization of the reaction parameters gave polyethylenes with narrow molecular weight distributions, indicating that single-site active species were formed; the molecular weights of the resultant polyethylenes could also be controlled. 相似文献
2.
Fe(III), Cr(III), Fe(II), Co(II) and Ni(II) chloride complexes supported by 2,6-bis[1-(iminophenyl)ethyl]pyridine have been synthesized and characterized along with single crystal X-ray diffraction. These complexes, in combination with MAO, have been examined in butadiene polymerization. The catalytic activity and regioselectivity are strongly controlled by metal center and cocatalyst (MAO/Co ratio dependent in the case of Co(II) complex). The activity decreases in the order of Fe(III) > Co(II) > Cr(III) ≈ Ni (II) complexes, in consistent with the space around the metal center. Polybutadiene with different microstructure content, from high trans-1,4 units (88-95% for iron(III) and Cr(III)), medium trans-1,4 and cis-1,4 units (55% and 35%, respectively, for iron(II)) to high cis-1,4 units 79% for Co(II) and 97% for Ni(II) can be easily achieved by varying of the metal center. In addition, mechanism speculation is also presented to elucidate the dependence of catalytic behaviors on metal and cocatalyst. 相似文献
3.
Pyridine-based tridentate ligand containing pendant NMe2 unit was used to prepare novel polyimides via one-stage solution polycondensation due to their stability under a variety of oxidative and reductive conditions. Ru (II) complex of the pydim ligand was synthesized starting from [RuCl2 (p-cymene)]2 and 2,6-bis [1-(p-dimethylaminophenylimino) ethyl] pyridine. A series of stable polyimides were synthesized from Ru (II) complex of 2,6-bis [1-(p-dimethylaminophenylimino) ethyl] pyridine (2) and various aromatic dianhyrides had inherent viscosities ranging from 1.31 to 1.55 dL/g and were soluble in polar solvents. The glass transition temperatures were 245–308°C, and the 10% weight loss temperatures were above 482–548°C. 相似文献
4.
Summary A group of new polyimides has been prepared by solution condensation of 2,6-bis[1-(p-dimethylaminophenylimino)ethyl] pyridine containing pendant NMe2 units and various dianhyrides in N-methylpyrrolidone (NMP). The tridentate (N-N′-N) pydim ligands were prepared by Schiff-base condensation of 2,6-diacetylpyridine and 4-dimethylaminoaniline in the presence of formic acid as catalyst. These polymers were investigated for their extraction capabilities for Zn(II), Mn(II), Cu(II), Cd (II) and Ni(II) and at different pH. Under different conditions enhanced selectivity was observed. Up to 98% quantitative recoveries were observed for all metals. 相似文献
5.
In the present study, iron complexes modified by differently substituted monodentate pyridine ligands containing a [Fe–O–Fe] unit have been synthesized, isolated and characterized. Noteworthy, the complexes are easily accessible by the reaction of pyridines with iron(II) chloride in the presence of molecular oxygen, which is the source for the oxido bridge as proven by labelling experiments. Interestingly, in dependency of the electronic and steric properties of the applied ligand different geometries have been observed by X-ray diffraction analysis. On one hand with pyridine or 4-dimethylaminopyridine as ligand (L) a L4ClFe–O–FeCl3 motif was accessible, while with 4-tert-butylpyridine a L2Cl2Fe–O–FeCl2L2 motif was realized. With the aid of Mößbauer spectroscopy an oxidation state + III was assigned for all iron centres. Moreover, the complexes were easily converted by addition of silver benzoate to trinuclear complexes with a [Fe3O] core. 相似文献
6.
《Inorganic chemistry communications》2000,3(3):107-110
The reaction of 2-[((2-(4-imidazoyl)ethyl)amino)carbonyl]-6-[((2-amino-2-methylpropyl)amino)methyl]pyridine (L) with ZnII(NO3)2·6H2O has afforded a novel one-dimensional polymeric ZnII complex, (ZnII(L)(NO3)2)n (2). Complex 2 crystallizes in the space group P21/n with a=8.955(3), b=13.216(3), c=18.941(3) Å, β=103.39(2)°, V=2180.6(10) Å3, and Z=4. The geometry of each ZnII is approximately a trigonal bipyramid: three nitrogens and one oxygen of the amide group are coordinated to the zinc while the fifth site is occupied by the imidazole nitrogen of a neighboring unit. 相似文献
7.
Two new iron–selenolate complexes [Cp*Fe(μ-SeMe)3FeCp*] (Cp* = η5-C5Me5) (1) and [Cp*Fe(μ-SeMe)3FeCp*][FeCl3] (2) were prepared by the oxidative addition reaction of MeSeSeMe with [Cp*FeCl]2 in 25% and 20% yields, respectively. In refluxing toluene, the methyl groups in the selenolate ligands of complex 1 were removed, affording a cubane cluster [Cp*4Fe4Se4] (3) in 50% yield. Complex 1 was oxidized by HBF4 to give [Cp*Fe(μ-SeMe)3FeCp*][BF4] (4), and the reverse reduction reaction occurred in the presence of CoCp2. 相似文献
8.
A novel iron(II) complex, trans-[FeL2(NCS)2][FeL2(CH3OH)2](NCS)2 (1) with 4-amino-3-(p-chlorophenyl)-5-(2-pyridyl)-1,2,4-triazole (L) has been successfully synthesized and characterized. X-ray crystallography analysis shows that 1 is the first example in the mononuclear triazole-based complexes consisting of two distinct molecules: trans-[FeL2(NCS)2] and trans-[FeL2(CH3OH)2](NCS)2 with each octahedral iron(II) center coordinated axial by two NCS− ions in Fe1 but two MeOH molecules in Fe2. Moreover, 1 can lose two MeOH molecules at 220 °C to form trans-[FeL2(NCS)2] (2) which can be transformed to 1 when recrystallizing 2 in methanol. Both 1 and 2 are high-spin species in the range of 1.8–300 K. 相似文献
9.
10.
Xing-wu Tan Xiao-hua Xie Jin-ye Chen Shu-zhong Zhan 《Inorganic chemistry communications》2010,13(12):1455-1458
The reaction of methyl anthranilate, sodium nitrite, and 2,6-diamino-pyridine affords a new compound, 2,6-diamino-3-[(2-carboxymethyl) phenylazo]-pyridine (L), which has been characterized with X-ray crystallography and NMR spectrum. The reaction of L and CoCl2? 6H2O or Cu(ClO4)2? 6H2O gives a dinuclear cobalt(II) complex [Co2L2Cl3]Cl (1), and a copper(I) complex [CuL2]ClO4 (2),respectively. They are characterized by X-ray crystallography, X-ray photoelectron spectroscopy, NMR spectra, magnetic measurement and emission spectra. Magnetic behavior of 1 denotes the occurrence of intramolecular antiferromagnetic interactions (J = ? 141.8 cm? 1). Complex 2 exhibits photoluminescence at 557 nm. 相似文献
11.
Summary Ethylene polymerization was conducted with a catalyst prepared by mixing 2,6-bis{1-[2,6-(diisopropylphenyl)imino]ethyl}pyridine
iron dichloride, Mg(C2H5)(n-C4H9) and Al(C2H5)1.5Cl1.5 in the presence of common alkylaluminium as cocatalyst. Both the activity and the molecular weight of polymers produced were
markedly dependent upon the polymerization temperature. The end-group analysis of polymers showed that the molecular weight
of polymers produced at higher temperature was reduced by chain transfer with Al(C2H5)3 in addition to β-hydrogen elimination. 相似文献
12.
Zhi Ma Yucai Ke Hang Wang Cunyue Guo Mingge Zhang Wen‐Hua Sun Youliang Hu 《应用聚合物科学杂志》2003,88(2):466-469
A supported iron‐based diimine catalyst (SC) was prepared by immobilization of 2,6‐bis[1‐(2,6‐diisopropylphenylimino)ethyl]pyridine iron chloride (I) on silica and employed in ethylene polymerization. The kinetic behavior of ethylene polymerization with SC was studied. The effects of the Al/Fe molar ratio, reaction temperature, and cocatalyst on the catalytic activity as well as the melting temperature, molecular weight, and morphology of the polymers obtained were also investigated. The results showed that good catalytic activities can be obtained even with a small amount of the cocatalyst methylaluminoxane (MAO) or triethylaluminum (AlEt3). The polyethylenes obtained with a supported catalyst had higher molecular weight, higher melting temperature, and better morphology than those obtained with a homogeneous catalyst. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 466–469, 2003 相似文献
13.
Ethylene polymerizations were performed using silica‐supported 2,6‐bis[1‐(2,6‐diisopropylphenylimino) ethyl] pyridine iron(II) dichloride with methylaluminoxane (MAO) as co‐catalyst. Silica was calcined at 600, 400 and 200 °C under vacuum for 8 h. The effect of calcination temperature of silica on the polymerization activity and the properties of the polymers obtained were examined. Catalyst–support interactions were examined by both a chemical method and XPS. It was observed that upon supporting the catalyst on the surface of silica, there is an increase in the binding energy of the metal center. However, no change in the metal binding energy was observed on supporting the catalyst to silica calcined at different temperatures. Ethylene polymerizations were performed using MAO as co‐catalyst. Catalysts were also prepared by first pretreating silica with MAO, followed by addition of the Fe(II) catalyst and contacting a complex of Fe(II) catalyst–MAO with silica previously calcined at 400 °C for 8 h. The results indicate that there is no chemical bonding between the support and the catalyst. Copyright © 2006 Society of Chemical Industry 相似文献
14.
《Inorganic chemistry communications》2007,10(8):948-951
The lantern complex PdII(μ-OOCMe)4CoII(NCMe) (1) was transformed into the pentanuclear double-lantern acetate-bridged heterobimetallic complex [Pd(μ-OOCMe)4Co]2(μ-OOCMe)2Pd(py)2 (py is pyridine) (2) by two routes: (i) reaction of 1 with pyridine and (ii) reaction of 1 with trans-Pd(py)2(OOCMe)2. Complex 2 × 3C6H6 was characterised by single-crystal X-ray diffraction, DTA-TG and magnetic susceptibility data. 相似文献
15.
Three new two-dimensional coordination polymers were constructed from 2,6-bis(imidazole-1-yl)pyridine (2.6-bip), terephthalic acid (1,4-bdcH2), and M(NO3)∙nH2O (M = Co, Cd). [M(2,6-bip)(1,4-bdc)] (1: M = Co; 2: M = Cd) were prepared under hydrothermal condition, whereas [Cd(2,6-bip)(1,4-bdc)∙xDMF] (3) was obtained under solvothermal condition in DMF solvent. Single-crystal X-ray analyses revealed the first example of a 2D 4-connected net of 66 topology in 1 and 2 and a rare 2D 4,5-connected net of 4,5 L20 topology in 3. All these complexes were thermally robust and emissive in solid-states. This work confirmed the versatility of using hingelike 2,6-bip as a linker and the importance of solvent effect in the process of framework formation. 相似文献
16.
《Inorganic chemistry communications》2007,10(6):709-712
A new dinuclear copper(II) compound, [Cu2(L1-O)2] (1) (L1 = (4E)-4-(2-hydroxybenzylideneamino)-1,2-dihydro-2,3-dimethyl-1-phenylpyrazol-5-one), and zigzag chain polymer, {[FeCl2(L2)]}n (2) (L2 = 1,5-dimethyl-2-phenyl-4-{[(1E)-pyridine-4-ylmethylene]amino}-1,2-dihydro-3H-pyrazol-3-one), were synthesized by solvothermal reactions and structurally characterized. The methyl group hydroxylation and the redox have been observed in the preparation of 1 and 2, respectively. 相似文献
17.
Min Ju Cha Jong Won Shin Young Hoon Lee Yang Kim Bong Gon Kim Kil Sik Min 《Inorganic chemistry communications》2009,12(6):520-522
The one-dimensional coordination polymer like fern branch, [CuII(L)]3[FeIII(CN)6]2·8H2O (1), which is linked by azamacrocyclic copper(II) complex and iron(III) hexacyanide, has been synthesized and characterized by single crystal X-ray crystallography and magnetic susceptibility measurement (L = 6,13-dimethyl-6-nitro-1,4,8,11-tetraazabicyclo[11.1.1]pentadecane). Compound 1 shows a weak ferromagnetic coupling between the copper(II) and low spin iron(III) ions in the one-dimensional chain structure. 相似文献
18.
Three platinum(II) complexes, including 2-(2-methoxy-phenyl) imidazo [4,5-f]-[1,10] phenanthroline, 2-(3-methoxy-phenyl) imidazo [4,5-f]-[1,10] phenanthroline and 2-(4-methoxy-phenyl) imidazo [4,5-f]-[1,10] phenanthroline, were synthesised and structurally characterised. In complexes 1–3, the platinum centre adopts a four-coordinate square planar geometry. In the MTT assay, these complexes exhibited considerable cytotoxicities against the SPC-A-2, MGC80-3, BEL-7404 and HeLa human tumour cell lines, with IC50 values in the range of 4.7 ± 0.8 to 23.3 ± 0.4 μM, and lower cytotoxicities towards the HL-7702 human normal liver cell line. By flow cytometry analyses, the HeLa cells treated with complexes 1–3 for 72 h exhibited DNA damage at the sub-G1 phase with a dose-dependent effect resulting in the blockage of cell cycle at sub-G1 phase, which might contribute to the cell apoptosis observed in HeLa cells. From the results of the CD, UV–vis and FID spectral analyses, complexes 1–3 showed good binding affinity with human telomeric G-quadruplex DNA. It suggested the potential inhibition on the telomerase activity, which should be a key antitumour mechanism for complexes 1–3. Furthermore, complex 1 with 2-substituted MOIP ligand, which may have lower steric hindrance for DNA intercalation, showed higher G-quadruplex DNA binding affinity than complexes 2 and 3. This was supported by the results from cell growth inhibition and cell apoptosis induction. 相似文献
19.
M. Abdallah S. A. Ahmed H. M. Altass I. A. Zaafarany M. Salem A. I. Aly 《Chemical Engineering Communications》2019,206(2):137-148
A novel compound, 2,6-bis-[1-(2-phenylhydrazono)ethyl]pyridine (BPEP), was synthesized and confirmed by NMR and IR spectroscopy. BPEP was examined as an inhibitor for the corrosion of zinc electrode in 1.0 M HCl. The inhibition efficiency of BPEP was assessed through various techniques such as hydrogen evolution, galvanostatic polarization, potentiodynamic anodic polarization, and electrochemical impedance spectroscopy. The inhibiting action of BPEP was explained in terms of the formation of a stable complex between zinc ions and BPEP and then adsorbed onto the zinc surface. The formation of the complex was established by FT-IR spectroscopy. A conductometric titration indicated that the stoichiometry of Zn+2:BPEP (metal:ligand) is 1:1. The adsorption follows the Langmuir isotherm. The Galvanostatic polarization measurements have shown that the BPEP molecule acts as a mixed-type inhibitor. The pitting potential shifted in the noble direction, indicating that the inhibition of pitting corrosion of zinc in the presence of BPEP.The activation energy and themodyanamic parameters of the adsorption process were calculated and have been explained. 相似文献
20.
《Inorganic chemistry communications》2003,6(5):431-434
A new iron (III) containing silsesquioxane compound, [Bu4N][((CH3)2CHCH2)7Si7O12FeCl] (4) was prepared by reacting [Bu4N][FeCl4] (3) with the isobutyl substituted silsesquioxane trisilanol, ((CH3)2CHCH2)7Si7O12H3, (1) in the presence of three equivalents of triethylamine, Et3N (2). The magnetic susceptibility of 4 was measured by Evans method, and the effective magnetic moment, μeff, is consistent with a high spin Fe (III) center. The composition and molecular structure of 4 was fully determined by IR, elemental analysis, APCI mass spec, and X-ray crystal analyses, and its potential as a precursor to a model of the structure and chemistry of the Fe-ZSM-5 catalyst is discussed. 相似文献