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1.
Nan Zhang Yu-Hua Fan Cai-Feng Bi Xia Zhang Peng-Fei Zhang Zhong-Yu Zhang Xin Li 《Journal of Inorganic and Organometallic Polymers and Materials》2013,23(6):1492-1500
Three novel transition metal coordination polymers, [Ni(C18H16N3O2)2·2CH3OH] n (1), [Zn(C18H16N3O2)2·4CH3OH] n (2) and [Cd(C18H16N3O2)2·2CH3OH] n (3) (C18H16N3O2=2-acetylpyridine-d-tryptophan) were synthesized and characterized by elemental analysis, IR, UV, 1H NMR and X-ray diffraction single crystal analysis. The analyses of the structures indicate that all three materials crystallize in the tetragonal crystal system, space group P41212. They have similar structures; i.e., the Schiff base coordinates in its deprotonated form and behaves as a hexadentate (4N+2O) coordinated ligand to form a distorted octahedron geometry. On the other hand, as a result of the alternate arrangement of chains through N–H···O intermolecular hydrogen bonds interactions, 2-D layers are formed for the three complexes. Furthermore, the luminescent properties and thermal stabilities of the three complexes were investigated. 相似文献
2.
《Inorganic chemistry communications》2003,6(1):94-96
Treatment of a MeOH solution of trans-[FeBr2(depe)2] (depe=Et2PCH2CH2PEt2) with HCCC6H10OH or HCC(CH2)nOH (n=1 or 2), in the presence of NaBPh4, forms the cyclic allenylidene trans-[FeBr(CCC6H10)(depe)2][BPh4] or the alkyne trans-[FeBr{η2-HCC(CH2)nOH}(depe)2][BPh4] (n=1 or 2) complexes, respectively. 相似文献
3.
《Inorganic chemistry communications》2003,6(9):1228-1233
Reaction of the solvent adduct MoO2Cl2(THF)2 with the 1,4-diazabutadiene ligands RNC(Ph)C(Ph)NR [R = (CH2)2CH3, (CH2)3Si(OMe)3] leads to complexes of the type MoO2Cl2(LL) in good yields at room temperature within a few minutes. The complex bearing the trimethoxysilyl groups was immobilized in the ordered mesoporous silica MCM-48 by covalent bonding. Solid state MAS NMR spectroscopy (13C, 29Si) confirms that the structural integrity of the complex was retained during immobilization, except for loss of methoxide groups due to the reaction with surface silanols. Powder X-ray diffraction (XRD) and N2 adsorption studies of the derivatized material indicate that the textural properties of the support were preserved during the grafting experiment and that the channels remained accessible. The modified material is active and selective in the epoxidation of cyclooctene at 55 °C using tert-butyl hydroperoxide as the oxidant. Stability was checked by recycling the solid catalyst several times. Some activity is lost from the first to second runs, but thereafter stabilizes. The catalytic behavior of the heterogenized catalyst was also compared with that observed in homogeneous phase for the complex with R=(CH2)2CH3. 相似文献
4.
Polymer-supported transition-metal-ion complexes of the N,N′-bis(o-hydroxy acetophenone) propylenediamine (HPPn) Schiff base were prepared by the complexation of iron(III), cobalt(II), and nickel(II) ions on a polymer-anchored N,N′-bis(5-amino-o-hydroxy acetophenone) propylenediamine Schiff base. The complexation of iron(III), cobalt(II), and nickel(II) ions on the polymer-anchored HPPn Schiff base was 83.44, 82.92, and 89.58 wt%, respectively, whereas the unsupported HPPn Schiff base showed 82.29, 81.18, and 87.29 wt % complexation of these metal ions. The iron(III) ion complexes of the HPPn Schiff base showed octahedral geometry, whereas the cobalt(II) and nickel(II) ion complexes were square planar in shape, as suggested by spectral and magnetic measurements. The thermal stability of the HPPn Schiff base increased with the complexation of metal ions, as evidenced by thermogravimetric analysis. The HPPn Schiff base showed a weight loss of 51.0 wt % at 500°C, but its iron(III), cobalt(II), and nickel(II) ion complexes showed weight losses of 27.0, 35.0, and 44.7 wt % at the same temperature. The catalytic activity of the unsupported and supported metal-ion complexes was analyzed by the study of the oxidation of phenol and epoxidation of cyclohexene in the presence of hydrogen peroxide. The supported HPPn Schiff base complexes of iron(III) ions showed a 73.0 wt % maximum conversion of phenol and 90.6 wt % epoxidation of cyclohexene, but unsupported complexes of iron(III) ions showed 63.8 wt % conversion of phenol and 83.2 wt % epoxidation of cyclohexene. The product selectivity for catechol (CTL) and epoxy cyclohexane (ECH) was 93.1 wt % and 98.1 wt % with the supported HPPn Schiff base complexes of iron(III) ions, but it was low with the supported Schiff base complexes of cobalt(II) and nickel(II) ions. The selectivity for CTL and ECH varied with the molar ratio of the metal ions but remained unaffected by the molar ratio of hydrogen peroxide to the substrate. The energy of activation for the epoxidation of cyclohexene and oxidation of phenol with the polymer-supported Schiff base complexes of iron(III) ions was 10.0 and 12.7 kJ/mol, respectively, but it was found to be higher with the supported HPPn Schiff base complexes of cobalt(II) and nickel(II) ions and with the unsupported HPPn Schiff base complexes of iron(III), cobalt(II), and nickel(II) ions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008 相似文献
5.
Devarayan Kesavan Manoharan Muthu Tamizh Mayakrishnan Gopiraman Nagarajan Sulochana Ramasamy Karvembu 《Journal of surfactants and detergents》2012,15(5):567-576
A series of 4-substituted N-(2-mercaptophenyl)salicylideneimine Schiff bases were synthesized and investigated for corrosion inhibition of mild steel in hydrochloric acid medium. Inhibition through adsorption mechanism is proposed for these inhibitors, which is well supported by electrochemical impedance spectroscopy, the Langmuir adsorption isotherm and Scanning Electron Microscope morphologies of inhibited and uninhibited mild steel specimens. The negative ?G ads indicates the spontaneous adsorption of the inhibitor on a mild steel surface. Among all the examined inhibitors, 5-bromo-N-(2-mercaptophenyl)salicylideneimine showed a higher inhibition efficiency. In order to reveal the usefulness of these Schiff bases as corrosion inhibitors under various circumstances, weight loss measurements were performed at various temperatures, acid concentrations and immersion times. 相似文献
6.
《Inorganic chemistry communications》2003,6(5):486-490
Ruthenium(II) complexes of the type [Ru(CO)(B)(L)] (B=AsPh3, pyridine, piperidine or morpholine; L=dianion of tetradentate Schiff bases) have been synthesized and characterized by physico-chemical methods. These complexes are found to be effective catalysts in the oxidation of primary and secondary alcohols using N-methylmorpholine-N-oxide as oxidant. The catalytic activity of these triphenylarsine complexes have been compared with that of triphenylphosphine complexes and with similar ruthenium(III) complexes. The formation of high valent Run+2O species as catalytic intermediate is proposed for the catalytic processes. 相似文献
7.
《Inorganic chemistry communications》2000,3(3):105-106
Reaction of tris(cyclopentadienyl)lanthanide with the tridentate Schiff base N-1-(ortho-methoxyphenyl)salicylideneamine in THF at room temperature affords the isolation of monomeric lanthanocene Schiff base complexes, (η5-C5H5)2Ln (OC14H13NO) (Ln=Sm (1), Er (2), Dy (3), Y (4)), which have been characterized by elemental analysis and mass spectra. The X-ray determination of 1 indicates that the complex is monomeric in which the metal center is coordinatively saturated by two cyclopentadienyl rings and two oxygens and one nitrogen from the Schiff base ligand. The average Sm–C bond distance is 2.723(7) Å, while those of the metal center to the Schiff base oxygens and nitrogen atoms are 2.232(4), 2.572(4) and 2.534(4) Å, respectively. 相似文献
8.
Jian Zhang Pingping Jiang Yirui Shen Weijie Zhang Gang Bian 《Journal of Porous Materials》2016,23(2):431-440
Molybdenum(VI) Schiff base complexes modified mesoporous SBA-15 hybrid heterogeneous catalysts were synthesized by the reaction of MoO2(acac)2 with mesoporous SBA-15 functionalized by grafting procedures of 3-aminopropyl-triethoxysilane and salicylaldehyde, respectively. The physico-chemical properties of the as-synthesized catalysts were analyzed by ICP-AES, XRD, N2 adsorption–desorption, FT-IR, SEM, TEM and EDX. The as-synthesized catalysts were effective in the catalytic epoxidation of cyclohexene. The catalytic activity can be further enhanced by silylation of the residual Si–OH groups using Me3SiCl, which was largely due to the higher content of Mo active sites. The conversion and selectivity reached to 97.78 and 93.99 % using tert-butyl hydroperoxide as oxidant for Mo–CH3–SA–NH2–SBA-15, while 81.97 and 89.41 % in conversion and selectivity for Mo–SA–NH2–SBA-15. At the same time, the catalytic performances of the hybrid materials were further systematically investigated under various reaction conditions (solvent, oxidants and alkenes, etc.). Mo–CH3–SA–NH2–SBA-15 catalyst can be recycled effectively and reused four cycles with little loss in activity. In addition, the results from hot filtration demonstrated that the catalytic activity mostly resulted from the heterogeneous catalytic process. 相似文献
9.
A set of six new polystyrene anchored metal complexes have been synthesized by the reaction of the metal salt with the polystyrene anchored Schiff base of vanillin. These complexes were characterized by elemental analyses, Fourier transform infrared spectroscopy, diffuse reflectance studies, thermal studies, and magnetic susceptibility measurements. The elemental analyses suggest a metal : ligand ratio of 1 : 2. The ligand is unidentate and coordinates through the azomethine nitrogen. The Mn(II), Fe(III), Co(II), Ni(II), and Cu(II) complexes are all paramagnetic while Zn(II) is diamagnetic. The Cu(II) complex is assigned a square planar structure, while Zn(II) is assigned a tetrahedral structure and Mn(II), Fe(III), Co(II), and Ni(II) are all assigned octahedral geometry. The thermal analyses were done on the ligand and its complexes to reveal their stability. Further, the application of the Schiff base as a chelating resin in ion removal studies was investigated. The polystyrene anchored Schiff base gave 96% efficiency in the removal of Ni(II) from a 20‐ppm solution in 15 min, without any interference from ions such as Mn(II), Co(II), Fe(III), Cu(II), Zn(II), U(VI), Na+, K+, NH4+, Ca2+, Cl?, Br?, NO3?, NO2?,and CH3CO2?. The major advantage is that the removal is achieved without altering the pH. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1536–1539, 2005 相似文献
10.
《Inorganic chemistry communications》2000,3(2):83-86
Reaction of the unsymmetrical and potentially dinucleating Schiff base ligand HL1 with copper(II) salts has given mono- and dinuclear metal complexes. The structure of a mononuclear complex of diprotonated HL1, [Cu(H2L1)(OH2)](ClO4)3·H2O·CH3OH, has been determined. 相似文献
11.
Two lanthanide complexes are achieved by utilizing H2salen/acac ligands (H2salen = N,N′-ethylenebis(salicylideneimine), acac = acetylacetonate). They are homonuclear [Nd4(μ3-OH)2(salen)2(acac)6(CH3OH)2]·CH3OH (1) and heteronuclear [NdYb(salen)2(acac)2] (2). The structures of the two complexes were determined by X-ray crystallographic studies and their photophysical properties were investigated. The homonuclear Nd4 complex exhibits characteristic metal-centered NIR emission. The heteronuclear NdYb shows ‘dual emission’ from both neodymium(III) and ytterbium(III) ions. 相似文献
12.
İsmet Kaya Ayşe Erçağ Ali Avcı Süleyman Çulhaoğlu 《Journal of Inorganic and Organometallic Polymers and Materials》2014,24(4):665-675
A new Schiff base, 4-(4-hydroxysalicylidenamino)-3-hydrazino-5-mercapto-1,2,4-triazole (4HSAHMT), and novel Schiff base oligomers of 4-salicylidenamino-3-hydrazino-5-mercapto-1,2,4-triazole (SAHMT), 4-(2-hydroxynaphthylidenamino)-3-hydrazino-5-mercapto-1,2,4-triazole (2HNAHMT), 4-(4-hydroxysalicylidenamino)-3-hydrazino-5-mercapto-1,2,4-triazole (4HSAHMT) and 4-(5-bromosalicylidenamino)-3-hydrazino-5-mercapto-1,2,4-triazole (BrSAHMT) were synthesized via oxidative polymerization using NaOCl as the oxidant. The structures of the oligomers were supported by FT-IR, UV–Vis, 1H-NMR, and 13C-NMR techniques. The compounds were further characterized by solubility tests, TG–DTA, and elemental analysis. The molecular weight distribution parameters of the compounds were determined by the size exclusion chromatography (SEC). According to SEC, the number average molecular weight (M n ) values of O-SAHMT, O-BrSAHMT, O-4HSAHMT and O-2HNAHMT were 2,700, 2,100, 2,700 and 1,000 g mol?1, respectively. The weight losses of O-SAHMT, O-BrSAHMT, O-4HSAHMT and O-2HNAHMT were 73, 76, 80 and 54 %, respectively, at 1,000 °C. TG analyses showed that the synthesized oligomers were stable toward thermal decomposition. The synthesized oligomers were converted to metal complexes with salts of VO(IV) and Cu(II). The doped and undoped electrical properties of oligomers and oligomer–metal complexes were determined by the four-point probe technique at room temperature and atmospheric pressure. 相似文献
13.
《Inorganic chemistry communications》2007,10(4):401-403
A aromatic Schiff base ligand, N, N′-bis((4, 4′-diethylamino)salicylidene)-1, 2-phenylenediamine (H2L), and its trinuclear zinc(II) complex, Zn3L2(CH3COO)2, were synthesized. The X-ray crystal structure of the complex reveals that two zinc ions show the coordination number of five and the third one has the coordination number of six. The complex exhibits blue-green emission as the result of the fluorescence from the intraligand emission excited state. 相似文献
14.
The expectant dithiocarbamate group end-functional poly(styrene) (PS) with a controlled molecular weight and low molecular weight distribution was synthesized conveniently via reversible addition-fragmentation chain transfer (RAFT) polymerization and was used to prepare polymer/metal composites with coordination chemistry. By the self-assembly technique, PS coordinated with the rare earth metal in N,N-dimethylformamide (DMF) to generate the fluorescent Eu–PS and Sm–PS complexes. Furthermore, PS-coated spherical silver nanoparticles (AgNPs) were prepared by reducing Ag+ to Ag0 under ultrasound irradiation in the presence of DMF and H2O. The well core/shell structure of the AgNPs was characterized by transmission electron microscopy (TEM). 相似文献
15.
《Inorganic chemistry communications》2007,10(5):583-585
An unusual heterotrinuclear complex [LCo(μ-L1, 1-N3)2(μ-L1)Ni(μ-1, 1-N3)2(μ-L1)CoL] (1) was obtained by the reaction of the precursor of half-sandwich nickel(II) complex [LNi(HL1)2(N3)] (2) and CoCl2 · 6H2O (L = hydrotris(3,5-dimethylpyrazolyl)borate; L1 = 3,5-dimethylpyrazolate), the complex 1 was characterized by X-ray single-crystal diffraction, elemental analysis, IR, UV–vis spectra and magnetic properties. 相似文献
16.
S. Knoll F. Tschwatschal U. Himmelreich F. Dietze R. Borsdorf 《Advanced Synthesis \u0026amp; Catalysis》1996,338(1):60-64
Complexes of Zn(II) with Schiff Bases of Hydrazine-O-methylcarbothionates – NMR-Spectroscopic Investigations Schiff bases of hydrazine-O-methylcarbothionates react as bi- or tridentate ligands with Zn(II) ions forming neutral metal complexes ( 1a-1g ). 1H-, 13C- and 15N-NMR-spectra of these complexes show the existence of configurational isomers of the CN-double bond. Furthermore, depending on the ligands 4 different coordination patterns with the donor atoms N2S2, N4, N2O2 and NOS are demonstrated. 相似文献
17.
《Inorganic chemistry communications》2000,3(11):627-629
Cobalt(II) complexes of the form CoX2(NH2CH2CH{OEt}2)2 [X=Cl, Br, I] react hydrolytically in solution to convert hemiacetal moieties to aldehydes, the latter undergoing Schiff base condensation. Complex decomposition and the separation of metal salt and organic material occur concomitantly. In contrast, thermal reactions afford metal complexed polyimines of the form CoX2{=NCH2CH=}2. Analyses are consistent with the liberation of four equivalents of ethanol per mole of CoX2(NH2CH2CH{OEt}2)2 via an autocatalytic cycle of hemiacetal hydrolysis and Schiff base condensation. Such thermal routes offer facile access to metal complexed polyimines. 相似文献
18.
Novel polyfunctional neutral organophosphorus ligands, namely 1,5-N,N'-bis[(diphenylphosphoryl)acetyl(alkyl)amino]pentanes [Ph2P(O)CH2C(O)NR]2(CH2)5 (Ia, R = C6H13; Ib, R = CH3), were studied as extractants for Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, and U from nitric acid solutions. The effect of both HNO3 concentration in the aqueous phase and that of the extractant in the organic phase on the extraction of metal ions is considered. The stoichiometry of the extracted complexes was determined by the slope analysis method. Compared with the related bisaminopentane [Ph2P(O)CH2C(O)NH]2(CH2)5 (Ic), the replacement of hydrogen atoms at the amide nitrogens by alkyl radicals (compounds Ia,b) leads to an increase of metal ions extraction. Bis-CMPO ligands Ia-c were found to possess higher extraction efficiency towards U(VI), Th(IV), and Ln(III) than their monophosphorylated analogue Ph2P(O)CH2C(O)N(C4H9)2. 相似文献
19.
Two Schiff base polymers were prepared from the respective monomers by condensation method using toluene and N-methyl-2-pyrrolidinone as solvent. They were complexed with Al(III), In(III), and Cu(II) trifluoromethane sulfonates (triflates), and AlCl3 Lewis acids and characterized by FT-IR, UV–Vis spectroscopy, and scanning electron microscopy (SEM). Homogeneous films were prepared by spin coating in the presence and absence of Lewis acids. Polymer–Lewis acid interaction was confirmed by FT-IR, UV–Vis spectroscopy, and SEM. Lewis acid composition in polymers was determined by FT-IR spectroscopy. Absorption spectra of these conjugated Schiff base polymer complexes exhibited smaller optical band gap than pristine polymers. These variations ranged from 2.4 to 1.4 and 3.3 to 2.0 eV. Absorption depends on the Lewis acid in the polymer and band gap on the nature of the metal incorporated in the polymeric backbone. Solubility increased by complexation. The obtained complexes were soluble in trifluoroacetic and formic acids and in m-cresol. Polymer–Lewis acid solutions in m-cresol were stable for 98 h; the others remained stable over several months. The results of this study revealed that optical, solubility, and band-gap properties of conjugated Schiff base polymers can be modified by Lewis acids and these could be studied by optoelectronics. 相似文献
20.
Schiff base bis (2— quinolidene)- diamine gives a purple-red complex with copper ions with a λmax at 530 mμ. The optimum pH for production of this complex is approximately 9.5. None of the metallic ions of the analytical groups II and III give rise to red complexes with the above Schiff base. Manganous (Mn2+) and stannous (Sn2+)ions as well as reducing agents such as hydrazine or hydroxylamine exert a catalytic effect on the rate of formation of these copper complexes. The thermal stability of the copper complex formed from the Schiff bases (2-quinoline-aldehyde with NH2-(CH2)n-NH2) is greater for diamine for which n = 4–6 than for n = 2–3. 相似文献