Study on Sythesis of Crosslinked Chitosan Prolymer and Its Use in the Removal of Urea

A novel bead from of ploymer of high sorption capacity for urea were obtained by the reaction of glutaric dialdehyde with chitosan dispersed in acetic acid solution.The sorption capacity reached-82.0mg/g sorbent at 37℃ and pH7.4 The concentration of urea in the buffer solution was 1300 mg/l.The sorption of urea was related to the degree of crosslinking of the sorbent,concentration ofurea,ionic strength and temperature.     

Coordination Sorption of Urea by Novel Urea Sorbent——Polymer-bound Metal Complexes

Urea can be sorbed by coordination (or complexation)with transitional metalpolyacrylic acid complex and transitional metal-polyacrylamide containing polyethylenepolyamine ligand complexes. The experimental results indicate that the sorbents can sorb about 60mg urea per gram of sorbent at 37℃ and the concentration of urea was 1300.0rag/1 in NaH_2PO_4 and Na_2HPO_4 buffer solution (pH=7.0) and the urea sorption capacity was affected by many factors such as other competive ligands, sorption time, pH and the concentration of urea.     

STUDY ON SORPTION OF UREA BY MEANS OF MNTAL-POLYMER COMPLEXES

Urea can be sorbed by complexation with metal-polyaerylic acidcomplex.The experimental results indicate that the coordination occursin the 0 atom of urea with Cu(Ⅱ)in Cu(Ⅱ)-polyaerylic acid complexand the sorption capacity of urea can reach about 60 mg per gram of theCu(Ⅱ)-polyacrylic acid complex.     

The role of nickel oxide additive in lowering the carbon dioxide sorption temperature of CaO

A new type of calcium-based regenerable carbon dioxide(CO2) sorbent, CaO-NiO, was synthesized via the sol-gel method. The as synthesized CO2 sorbent was in the form of nanoparticles. The CO2 sorption temperature and capacity of the sorbent were examined using thermogravimetric analysis(TGA). The CaO-NiO sorbent is able to capture CO2 at a lower sorption temperature(465C) than pure calcium oxide(CaO)(600C). The role of NiO in the CaO-NiO sorbent in lowering the CO2 sorption temperature was also investigated. The sorbent was characterized by X-ray diffractometer(XRD), N2adsorption-desorption analysis, high resolution transmission electron microscopy(HRTEM) and scanning electron microscopy(SEM). CaO and NiO were found to coexist in the sorbent. Neither solid solution nor mixed metal oxide was formed. NiO did not react with CO2 in the sorption process; but it worked like a catalyst to promote the CaO carbonation reaction. It is suggested that this new CaO-NiO sorbent may have a promising application as an effective CO2 sorbent with lower energy consumption.     

FORMATION OF THE CRYSTALLINE INCLUSION COMPLEX BETWEEN β-CYCLODEXTRIN AND POLYPROPYLENE

PP can be included in the cavities of cyclodextrin (CD). The crystalline inclusion complex between β-CD and lowmolecular weight polypropylene (PP) was obtained and investigated. α-CD and γ-CD did not form crystalline inclusioncomplexes with PP. The FTIR spectra, TGA, X-ray diffraction spectra were studied, ~1H-NMR spectra and ~(13)C CP/MAS NMR spectra were used to characterize the crystalline inclusion complexes.     

SYNTHESIS AND CATALYTIC PROPERTY OF POLYSTYRENE SUPPORTED GLUTAMIC ACID SCHIFF BASE COMPLEX OF Mn（ Ⅱ ） IN AEROBIC OXIDATION OF CYCLOHEXENE

The polystyrene supported glutamic acid Schiff base complex of Mn （ Ⅱ ） （PS-Sal-Glue-Mn） was prepared with chloromethylated styrene polymer beads, 2,4-dihydroxybenzaldehyde, L-glutamic acid and manganese （ Ⅱ ） acetate tetrahyrate. The polymeric ligand and the complex were characterized by FT-IR, small area X-ray photoelectron spectroscopy （XPS） and 1CP-AES. In the presence of the manganese complex, cyclohexene （1） was effectively oxidized by molecular oxygen without reductant. The major products of the reaction were 2-cyclohexen-l-ol （2）, 2-cyclohexen-l-one （3） and 2-cyclohexen-1- hydroperoxide （4）, which was different with typical oxidation of cyclohexene. The influence of reaction temperature and additive for oxidation had been studied. The selectivity of 2-cyclohexen-1-hydroperoxide varied with reaction time and different additives. The mechanism of cyclohexene oxidation had also been discussed.     

NONCONVENTIONAL EMULSION POLYMERIZATION OF ACRYLONITRILE CATALYZED BY in situ METAL COMPLEX

Nano-sized polyacrylonitrile (PAN) particles were prepared under the catalytic effect of in situ developed CoCl2/EDTA complex with ammonium persulfate as the initiator in the absence of any added emulsifier. The emulsion polymerization was studied at varying concentrations of the initiator, monomer, complex and solvent over a temperature range of 30-70℃. The overall activation energy (Ea, 49.79 kJ/mol), energy of dissociation of initiator (Ed,82.68 kJ/mol), number of micelles (0.163×1018) and the viscosity average molecular weight of the polymer were computed. The distribution of particle sizes was determined by transmission electron microscopy (TEM). It was found that the oil-in-water polymerization was stabilized by the presence of the CoCl2/EDTA in situ complex reducing the particle size into the nano order. The average diameters of PAN nano particles, obtained by TEM, were in the range of 50-150 nm at the maximum conversion. The experimental particle size was mainly dependent on the concentration of the complex and temperature.     

APPLICATIONS OF DSCPCF MODEL IN RARE EARTH COMPLEXES(Ⅴ)——ANALYSIS OF SPECTRA OF THE NEODYMIUM AND ERBIUM TETR A (2-THENOYLTRIFLUOROACETONE) MONO PIPERIDINE COMPLEXES

The complexes, Nd(TTA)_4·HP and Er(TTA)_4·HP, have been prepared, and their UV-VIS-NIR absorption spectra measured. The matrix element expressions with J=1/2—15/2 of f~3 and f~(11) configurations in D_4 symmetry field were derived with the Double Sphere Coordination Point Charge Field Model. And the influence of change in symmetry of the complex unit REO_8 on splitting of their levels was discussed. Based on theoretical calculations, the absorption peaks in the spectra were assigned.     

ESR spectra studies of Cu(Ⅱ) 2,4-dihydroxybenzaldehyde tyrosine complex

A novel Schiff base derived from 2,4-dihydroxybenzaldehyde and tyrosine and its copper(Ⅱ)complex have been synthesized and characterized.The composition of the complex is K[CuL] H2O,where L=H11C16NO5.ESR spectra of the copper(Ⅱ)complex were investigated at different temperatures and in various solvents.The second order effect and the relaxation effect were observed in the solution spectrum at room temperature,which was satisfactorily explained by spin Hamiltonian.The bonding parameters of copper(Ⅱ)complex were calculated using spectral parameters from ESR spectra at low temperature.Its bonding characterization and stability were disscussed.The result shows that the in-plane a-bond and the in-plane π-bond in the complex all play an important role.     

SYNTHESIS OF POLY（3,4-AZOPYRIDYLENE） AND OXYGEN-BINDING AFFINITY OF ITS COMPLEX WITH COBALTPORPHYRIN

Synthesis and characteristics of poly(3,4-azopyridylene) (PAP), conductivity and oxygen-binding affinity of its complex with meso-α,α,α,α-tetrakis(o-pivalamidophenyl) porphyrinatocobalt(Ⅱ) (CoP) were studied. PAP was prepared by oxidative polymerization of 3,4-diaminopyridine (DAP) in DMF solution using CuCl/pyridine as the catalyst. IR and NMR results showed that the peak of amido group in DAP was converted to the azo group in PAP and a π conjugated polymer was synthesized. The average molecular weight of PAP was determined to be 5.0 × 103. The PAP-CoP complex was prepared by complexing the pyridyl group of PAP with the fifth coordination site of CoP in DMF solution. In comparison with the CoP complex with a non-π conjugated polymer, the PAP-CoP complex shows good electroconductivity of 5.8 × 10-6 Scm-1. The PAP-CoP complex displays a reversible change in the UV-Visible absorption spectrum from the deoxy form to the oxy or oxygen-binding one with an isosbestic point, in response to the partial oxygen pressure of the atmosphere. The oxygen-response behavior was monitored at the absorbance ascribed to the oxy form at 548 nm to give the oxygen-binding affinity.The oxygen-binding equilibrium curves of PAP-CoP complex obey a Langmuir isotherm. DMF has great effects on the oxygen-binding properties of the PAP-CoP complex. The oxygen-binding affinity of PAP-CoP complex in the solid state is higher than that in DMF solution. With decreasing temperature, the oxygen-binding affinity of the PAP-CoP complex increases.     

水杨醛酪氨酸铜配合物合成和EPR波谱

A new Schiff base derived from tyrosine and salicylidene and its copper(Ⅱ) complex have been synthesized and characterized by elemental analyses,molar conductances,thermal analyses,infrared spectra,electronic spectra and EPR spectra.The composition of the complex is K[CuL(Ac)]•H2O, where L=H13C16NO4. EPR spectra of the copper(Ⅱ) complex were investigated in various solvents at different temperatures.It is found that the linewidth of four hyperfine lines on solution spectra at room temperature is unequal and changes with mⅠ ,this could be satisfactorily explained by the relaxation effect.The relaxation time and the relaxation rate were calculated.By using spectral parameters from solution spectra at low temperature,the bonding parameters of Cu(Ⅱ) complex were calculated.The bonding characterization and stability of the complex were disscussed.The results show that the in plane 螵瞓ond and the in plane 皙瞓ond in the complex all play an important role.     

ANALYSIS OF FRAGMENT INTERACTION AND ASSIGNMENT OF ELECTRONIC SPECTRUM FOR COMPLEX ION[S2MoS2FeCl2]^2—

<正> The electronic structures of complex ion [S2MoS2FeCl2]2- (1) and its fragments MoS42- (2) and FcCl2(3) have been calculated base on the LCAO-HFS method with restricted open shell or closed shell. The interaction between the fragments 3 and 2 and the formation of complex ion 1 have been discussed. It was found that the Fe(Ⅱ) donated electrons to the Mo(Ⅵ)and accepted electrons from the sulphur ligand and that the stability of complex ion 1 is contributed from both direct and indirect interactions through the bridging sulphur atoms. In addtion, the electron transition energies of complex ion 1 were calculated and its electronic absorptions were assigned. It was shown that the calculated wavelengths of the absorption bands are in agreement with the observed ones.     

POLYROTAXANE WITH π-CONJUGATED PORPHYRIN AND POLYAZOMETHINE SYSTEMS PREPARED FROM A TYPE OF PORPHYRIN-DIALDEHYDE AND COMPLEX OF β-CYCLODEXTRIN WITH 1,4-PHENYLENEDIAMINE

The synthesis of 5,15-bis[4-(methoxycarbonyl)phenyl]-10,20-diphenylporphyrin (2) and its reduction to 5,15-bis[4-(hydroxymethyl)phenyl]-10,20-diphenylporphyrin (3), and so its oxidation to provide 5,15-bis(4-formylphenyl)-10,20-diphenylporphyrin (4) are reported. The copolymer possessing β-cyclodextrin (β-CD), π-conjugated porphyrin and polyazomethine systems was synthesized by the polycondensation of porphyrin-dialdehyde monomer (4) and β-cyclodextrin/1,4-phenylenediamine complex (5). The monomers and the copolymer were characterized by UV-Vis, 1H-NMR and IR spectra. Furthermore, 1H-NMR and FT-IR spectra confirmed locating the aromatic ring of 1,4-phenylenediamine molecule in the center of β-cyclodextrin cavity.     

氧化铝对稀土有机配合物掺杂溶胶凝胶玻璃结构及发光性能的影响

Both silica glass materials singly doped with rare earth organic complex and co-doped with Al^3 were prepared by in situ sol-gel method respectively. XRD and SEM measurements were performed to verify the non-crystalline structure of the glass. The excitation spectra, emission spectra and IR spectra were measured to analyze the influence of the glass contents on the structure of the glass and the energy level of the doped Eu(IH) ions. The effect of Al^3 on the photoluminescence properties of rare earth organic complex in silica glass was investigated. The IR spectra indicated that the in situ synthesized europium complex molecule was confined to the micropores of the host and the vibration of the ligands was frozen. When Al2O3 was doped into the silica host gel, the rare earth ions in the silica network were wrapped up and dispersed by Al2O3, so the distribution of Eu(Ⅲ) complex in the host was morehomogeneous, and the luminescence intensity of ^5D0-^7F2 transition emission of the Eu^3 ions was improved. The results showed that an appropriate amount of Al^3 added to the gel glass improved the emission intensity of the complex in the silica glass, and when the content of Al2O3 reached 4 mol%, the maximum emission intensity could be obtained compared with that of other samples containing different Al2O3 contents.     

Synthesis, Electrochemistry, and Photophysics of a Novel Binuclear Polypyridyl Ru(Ⅱ) Complex with an 1,8-Adipoylamidobis(1,10-phenanthroline-5-yl) Ligand

The present paper covers the syntheses of 1,8-adipoylamido-bis(1,10-phenanthroline-5-yl)(bphaa) and its binuclear complex {[(bpy)2Ru]2(bphaa)}(PF6)4, where bpy is 2,2′-bipyridine. The two novel compounds were confirmed by means of elemental analysis, IR, LD-MS and 1H NMR, and 1H NMR spectra were completely assigned in virtue of 1H-1H COSY. The electrochemical behavior of the binuclear Ru(Ⅱ) complex was obtained using cyclic and square-wave voltammetry. Its photophysical property was investigated by electronic absorption, fluorescence excitation and emission spectra.     

STUDIES ON FLUORESCENCE SPECTRA OF SAMARIUM EUROPIUM TERBIUM AND DYSPROSIUM WITH BENZOYL UREA DERIVATIVES AND PHENANTHROLINE

Rare earth chelates of benzoyl urea derivatives were prepared in ethanol and fluorescence spectra of these chelates were studied in detail. A composition of [RE(BU)_3Phen] (NO_3)_3 was obtained. Correlation between chemical properties of ligands, chelates and spectroscopy was discussed. Intramolecular energy transfer in rare earth chelates was explained.     

Novel Monomeric Phenanthroline—Thallium（Ⅲ） Complexes Multinuclear NMR Characterization in Organic Solvents

A novel complex of monomeric thallium (Ⅲ） with the nitrogen donor ligand phenanthroline (phen) has been prepared and characterized by multimuclear NMR(^1H,^13C,^205Tl). The three complexes exist in equilibria in DMSO and acetonitrile solution, which was proved by the ^205Tl NMR spectra. The ^1H and ^13C NMR spectra of tris-phen T1(Ⅲ） complex have been measured, where the spin-spin coupling between T1(I=1/2) and ^13C or ^1H signals were observed with the ^1H and ^13C NMR spectroscopy in acetonitrile. The coupling constants are presented and the chemical shifts of complexes are discussed in detail.     

Sorption Removal of Pb（Ⅱ） from Solution by Uncalcined and Calcined MgAl-Layered Double Hydroxides

Layered double hydroxide （LDH） with a Mg/Al molar ratio of 1 ： 1 was synthesized by using a co-precipitation method and its calcined product （CLDH） was obtained by calcination of the MgAl-LDH at 500 ℃. The sorption removal of Pb^2＋ from solution was investigated, finding that both LDH and CLDH show good sorption ability and they could be used as a new type of environmental sorbent for the removal of Pb^2＋ from water. The sorption kinetics and the sorption isotherms of Pb^2＋ on both LDH and CLDH can be described by the pseudo-second order kinetics and Freundlich isotherm, respectively, under the studied conditions. The sorption amounts of Pb^2＋ on LDH and CLDH are independent of pH in a pH range of about 3-10. The presence of NaNO3 may inhibit the sorption of Pb^2＋ on LDH while hardly affect that on CLDH. The sorption mechanism of Pb^2＋ on LDH and CLDH may be attributed to the surface precipitation and the surface complex adsorption. The surface complex adsorption may be further distinguished to the chemical binding adsorption forming the inner-sphere surface complexes and the electrostatic binding adsorption forming the outer-sphere surface complexes. The sorption mechanism of Pb^2＋ on LDH may be attributed to the surface precipitation and the electrostatic binding adsorption, while that on CLDH may be attributed to the surface precipitation and the chemical binding adsorption.     

INVESTIGATION ON SYNTHESIS, STRUCTURE AND PROPERTIES OF THE CLUSTER COMPLEX,[(MoS_4)Fe(MoS_4O)] [(C_4H_9)_4N]_3

In this paper, we report a new Mo-Fe-S cluster complex containing an oxygen ligand. Itwas synthesized by the reaction of (NH_4)_2 MoS_4, FeCl_3 in the solution of sodium glycol. The chemical formula of the crystal, [(MoS_4) Fe (MoS_4O)] [(C_4H_9)_4N]_3, was characterized byX-ray. This complex was determined by IR, UV/Vis and Mossbauer spectra as well. The re-suits from Mossbauer spectra of the complex show an isomer shift, δ_m = 0.2263mm/s and aquadrupole splitting, E_q = 0.4527mm/s. The complex has some activity for the reduetion of aectylene to ethylene in the presenceof KBH_4.     

PURIFICATION AND CHARACTERIZATION OF D_1-D_2-Cyt.b_(559) COMPLEX WITH THE ACTIVITY OF DCIP PHOTOREDUCTION FROM BROAD BEAN LEAVES

A PSII reaction center complex consisting of three polypeptides, D_1, D_2 and Cyt. b_(559), was first purified from broad bean leaves. The complex was fairly active inDCIP photoreduction in the presence of DPC, and showed signal Ⅱs either in the dark or under illumination. The complex also contained manganese atoms. Its Mn~(2+)-EPR intensity decreased by about 40% under continuous illumination and recovered to the original level when the complex was transferred to the dark. The above results indicated that the complex reported here contains all of the PSII electron transport chain components from the secondary donor Z to the stable primary electron acceptor Q_A, and it is possible that the complex contains manganese binding sites. The alternation in dark and illumination can induce reversible valence changes of the manganese atoms in the purified complex.