Influence of variables on the synthesis of CoFe_(2)O_(4)pigment by the complex polymerization method

Synthetic inorganic pigments are most widely used in ceramic applications due to their excellent chemical and thermal stability and their lower toxicity to both human and environment as well.In the present work,black ceramic pigment CoFe_(2)O_(4)has been synthesized by the complex polymerization method(CPM)with good chemical homogeneity.In order to study the influence of variables on the process of obtaining pigment through CPM,2^((5-2))fractional factorial design with resolution III was used.The variables studied in the mathematical modeling were:citric acid/metal concentration,pre-calcination time,calcination temperature,calcination time,and calcination rate.Powder pigments were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),and UV-visible(UV-Vis)spectroscopy.Based on the results,the formation of cobalt ferrite phase(CoFe_(2)O_(4))with spinel structure was verified.The color of pigments obtained showed dark shades,from black to gray.The model adjusted to the conditions proposed in this study due to the determination coefficient of 99.9%and variance(R²)showed that all factors are significant at the confidence level of 95%.

A Novel Phenoxyimine-based Schiff Base Ligand and Its Mononuclear Nickel(Ⅱ) Complex：Synthesis,Crystal Structure,Norbornene Polymerization and Catalytic Activity

A novel phenoxyimine-based Schiff base ligand and its mononuclear complex [C（58）H（52）N2NiO2]（L = 2-benzhydryl-4-dimethoxy-3,5-dimethyl-salicylaldehyde） has been synthesized and characterized by IR spectrum, elemental analysis, TG, WAXD spectra, ^1H NMR and ^（13）C NMR. In addition, the molecular structure has been measured by single-crystal X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P21/c with a = 14.510（6）, b = 18.573（7）, c = 20.961（6） A, β = 123.453（19）°, V = 4713（3）A^3, Mr = 867.73, Z = 4, Dc = 1.223 g/cm^3, μ = 0.456 mm^-1, F（000） = 1832, the final R = 0.0685 and wR = 0.1758（I 〉 2σ（I））. The complex was used as homogeneous catalysis of polymerization of norbornene, and the MAO as cocatalyst. The nickel complex exhibited good catalytic activity up to 1.913 × 10^7 g of PNB（mol of Ni）^-1h^-1,and the yields of these reactions depend on the nature of the substituent in the aromatic ring.

Polymerization of Phenyl Isocyanate by Divalent Samarium Complex (ArO)_2Sm(THF)_4 (ArO=2,6-di-tert-butyl-4-methylphenoxo)

Phenyl isocyanate was for the first time successfully polymerized by divalent samarium complex (ArO)2Sm(THF)4. The monomer concentration and temperatur affected the polymerization greatly.

Synthesis, Structure and Norbornene Polymerization Catalyzed by Nickel(Ⅱ) Complex Bearing N,O-bis(1-(6-ethylpyridin-2-ylimino)-methylenyl)naphthalen-2-ol Ligand

The title complex bis{1-{[（6-ethyl-2-pyridinyl）imino]methylenyl}-2-naphthale- nolato-N,O}-nickel（lI） （C36H32NnO2Ni） has been synthesized by the reaction of l-{[（6-ethyl-2- pyridinyl）imino]methylenyl}-2-naphthalenol with Ni（CH3COO）2·4H2O, and characterized by IR spectrum, elemental analysis and TG. The complicated space structure has been confirmed by single-crystal X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P21/c with a = 11.410（4）, b = 14.382（4）, c = 18.121（6） ,A, β = 97.147（6）% V= 2950.5（16）A3, C36H32N4O2Ni, Mr = 611.37, Z = 4, Dc = 1.376 g/cm3, μ = 0.698 mm-1 F（000） = 1280, the final R = 0.0519 and wR = 0.1493 （1 〉2σ（I））. This title compound was used as precatalysts for the polymerisation of norbornene. When activated with MAO, the complex exhibited excellent catalytic activity up to 1.98 × 107 g ofPNB （mol of Ni）-1 h-1 with high monomer conversion.

Synthesis, Structure and Norbornene Polymerization Activity of a Novel Palladium(Ⅱ) Complex with N,OBis{1-[[(3-methyl-pyridin-2-yl)amino]methyl-phenyl]-2-hydroxy-3,5-di-tert-butylphenol} Ligand

The title complex bis{1-[[（3-methyl-pyridin-2-yl） amino] methyl-phenyl]-2-hydroxy-3,5-di-tert-butylphenol} palladium（C_（42）H_（56）O_2N_4Pd） has been synthesized by the reaction of 1-[[（3-methyl-pyridin-2-yl）amino]methyl-phenyl]-2-hydroxy-3,5-di-tert-butylphenol with Pd（OAc）_2, and was characterized by IR and elemental analyses（C, H, N）. Single-crystal X-ray diffraction analysis of the complex revealed an almost parallelogram geometry of the metal center, space group P1 with a = 12.3870（13）, b = 12.9673（12）, c = 14.3998（4） ？, α = 67.53（2）, β = 75.34（2）, γ = 86.89（3）°, V = 2065.5（3） A3, M_r = 773.32, Z = 2, D_c = 1.243 g/cm^3, μ = 0.489 mm^（-1）, F（000） = 816, the final R = 0.0649 and wR = 0.1567. The compound was investigated for the catalytic behavior towards norbornene（NB） vinyl addition polymerization. And the complex exhibits high catalytic activities up to 1.668 × 10~7 g of PNB（mol of Pd）^（-1） h^（-1） with high monomer conversion using methylaluminoxane（MAO） as the cocatalyst.

STUDIES ON ORGANO-MOLYBDENUM AND TUNGSTEN COMPOUNDS(Ⅲ)——CATALYTIC POLYMERIZATION OF ACETYLENE BY M-O-C BOND-CONTAINING COMPLEXES OF Mo AND W

Catalytic polymerization of acetylene in the presence of n5-C5H5-M-(CO)3 R (M=Mo,W;R=CH3-,C2H5-) has been studied.The results show that these complexes possess catalytic activities for the polymerization and copolymerization of monosubstituted acetylene.The catalytic mechanism has been preliminarily discussed.It is suggested that the active species be metal-car-bene.In our previous publications we reported the synthesis of some new Fischer's molybdenum and tungsten-carbene complexes and catalytic activity for alkyne polymerization.The results show that the activity of Fischer's molybdenum-carbene is higher than that of tungsten.The catalytic polymerization of alkyne by M-σ-c bond-containing complexes of molybdenum and tungsten has not been reported yet in literature.Therefore,four M-σ-C bondontaining complexes of molybdenum and tungsten were synthesized by using the method reported in the literature,and catalyst polymerization of alkyne by these complexes was examined.

Alcohol-dispersed polymer complex as an effective and durable interface modifier for n-i-p perovskite solar cells

Abundant interfacial defects remain a significant challenge that hampers both the efficiency and stability of perovskite solar cells(PSCs).Herein,an alcohol-dispersed conducting polymer complex,denoted as PEDOT:F(Poly(3,4-ethylene dioxythiophene):Perfluorinated sulfonic acid ionomers),is introduced into the interface between perovskite and hole transporting layer in regular-structured PSCs.PEDOT:F serves as a multi-functional interface layer(filling grain boundaries and covering perovskite's grain-surface)to achieve a robust interaction with organic groups within perovskites,which could induce a structural transformation of PEDOT to increase its conductivity for the efficient hole-transport.Furthermore,the strong interaction between PEDOT and perovskites could promote an effective coupling of undercoordinated Pb~(2+)ions with the lone electron pairs near O&S atoms in PEDOT molecules,thereby enhancing defect passivation.Additionally,PEDOT:F with inherent hydrophobic properties prevents effectively moisture invasion into perovskites for the improved long-term stability of the PSCs.Consequently,the PEDOT:F-based PSCs achieved a champion efficiency of 24.81%,and maintained ca.92%of their initial efficiency after 7680 h of storage in a dry air environment,accompanied by the enhanced photothermal stability.

Synthesis and characterization of yttrium-aluminum-iron and yttrium-cerium-iron citric complexes

Fe-, Y-Fe-Al- and Y-Ce-Fe- citrates were synthesized in ethylene glycol （EG） medium under conditions similar to those used in the polymerized complex method. Their elemental composition, IR,^ 13C and ^1H NMR, X-ray photoelectron and Mossbauer spectra were studied, and formulae describing their composition were proposed. The complexes contained EG bonded as adduct and ester with citric acid ligand and did not contain ligands with deprotonated alcoholic groups. The complexes consisted of agglomerated spheres, 0.7-3 μm in diameter. The local composition of the products was established by energy dispersive X-ray microanalysis. The comparison of the number of the ligands, their average electrical charge and the esterification degree of mono-, di- and trimetallic complexes proved the mixed-metal nature of the species studied. The thermal decomposition of the complexes was studied and a general scheme of the processes taking place was proposed. Highly crystalline, phase homogeneous YaFe4AlO12 was produced after heating the respective complex at 1000 ℃. Ce-doped yttrium-iron garnet, similarly prepared, contained traces of CeO2.

Synthesis and Photophysical Properties of Dy^(3+) and Gd^(3+) Polymeric Complexes with Functionalized Polybenzimidazole Containing β-Diketone Side Group

The polymeric ligand PBIa （functionalized polybenzimidazole containing β-diketone side group） was successfully synthesized via the reaction of polybenzimidazole （PBI） with 3-Br-acetylacetone in DM SO solvent using Nail as the deprotonation reagent. Its corresponding polymeric complexes of Dy^3＋ and Gd^3＋ were prepared and characterized by FT-IR, ^1H NMR, molar conductance measurements, and thermal analysis. The photoluminescence properties and the probable mechanism of the Dy and Gd complexes were studied. The measurement and analysis of the thermal properties showed that these were thermal stable.

PREPARATION AND MAGNETIC PROPERTIES OF POLYMERIC COMPLEXES CONTAINING 1,10-PHENANTHROLINE

A series of polymeric complexes were prepared from Fe^2＋, Co^2＋ or Ni^2＋ and poly（Schiff base） （DAPcIPA）, which was obtained by polycondensation of 5,6-diamino-1,10-phenanthroline （DAP） with isophthalaldehyde （IPA）. The structures of the polymer and the polymeric complexes were characterized by IR, 1^H-NMR and elemental analysis. The magnetic behavior of these complexes was measured as a function of magnetic field strength （0-3.98 ~ 106 A/m） at 5 K and as a function of temperature （5-300 K） at a magnetic field strength of 2.39 × 10^6 A/re. Experimental results show that DAPcIPA-Ni^2＋, DAPcIPA-Co^2＋ are soft ferromagnets while DAPcIPA-Fe^2＋ exhibits features of an antiferromagnet.

Polymeric complex micelle loaded with axially substituted silicon(Ⅳ) phthalocyanine

A novel axially substituted silicon（IV） phthalocyanine, namely di-pyridyloxy axially substituted silicon（IV） phthalocyanine 2 was synthesized and characterized by UV/vis, IR, elemental analysis, MS as well as IH NMR spectroscopy. Hydrophobic 2 was encapsulated by amphiphilic triblock copolymer poly[N^e-（benzyloxycarbonyl-lysine]-poly（ethylene glycol）-poly [N^e-（benzyl oxycarbonyl） （PLL（Z）-b-PEG-b-PLL（Z）） to form hydrophobic 2-loaded polymeric complex micelle （PIC） （2-loaded P/C）. Atom force microscopy （AFM） image showed that 2-loaded PIC formed a spherical nanocarrier with approximately 35-50 nm in diameter. The fluorescence intensity and lifetime of 2-loaded PIC was significantly enhanced bv the incorporation 2 into PIC nanocarrier.

Synthesis, Structure and Catalytic Activity of a Palladium(Ⅱ) Complex Based on 4-Chloro-2-[(6-methyl-pyridin-2-ylimino)-methyl]-phenol Ligand

The title complex bis{4-chloro-2-[（6-methyl-pyridin-2-ylimino）-methyl]-phenol}-palladium（Ⅱ）（C_（26）H_（20）Cl_2N_4O_2Pd） has been synthesized by the reaction of 4-chloro-2-[（6-methylpyridin- 2-ylimino）-methyl]-phenol with Pd（CH_3COO）_2, and characterized by IR spectrum and elemental analysis. Single-crystal X-ray diffraction analysis results further confirmed the molecular structures. The crystal belongs to the monoclinic system, space group P2_1/c with a = 4.1324（2）, b = 23.5432（16）, c = 11.8943（8） A, β = 91.238（5）o, V = 1156.93（12） ？~3, C_（26）H_（20）Cl_2N_4O_2Pd, M_r = 597.76, Z = 2, D_c = 1.716 g/cm^3, μ = 1.067 mm^（-1）, F（000） = 600, the final R = 0.0247 and w R = 0.0677（I 〉 2σ（I））. In the presence of methylaluminoxane（MAO）, the complex exhibits excellent catalytic activities（1.737×10~7 g of PNB（mol of Pd）^（-1）·h^（-1）） in the vinyl polymerization of norbornene.

Syntheses,Structures and Photoluminescent Properties of Cd(Ⅱ)Polymeric Complexes Based on 5-Aminoisophthalic Acid and Bipyridine Co-ligands

Two novel complexes, namely {[Cd（AIP）（4,4＇-bpy）]·1.3DMF}n（1） and [Cd（AIP）（2,2＇- bpy）]n（2）, have been synthesized through solvothermal reaction（H2AIP = 5-aminoisophthalic acid, 2,2＇-bpy = 2,2＇-bipyridine, 4,4＇-bpy = 4,4＇-bipyridine, and DMF = N,N＇-dimethylformamide） and structurally determined by single-crystal X-ray diffraction. Complex 1 shows a three-dimensional（3D） layer-pillar framework with rectangular channels, while complex 2 displays a two-dimensional（2D） wave net architecture. Furthermore, 1 and 2 were characterized by elemental analysis, infrared spectra（IR）, thermal gravimetric analyses（TGA） and fluorescence measurements. The luminescent properties of 1 dispersed in various organic solvents have been investigated systematically, demonstrating high selectivity for acetone via the fluorescence quenching effect.

Synthesis,Crystal Structure and Catalytic Performance of the Trifluoro-substituted Mono(β-diiminato)Copper(Ⅱ)Complex

Two novel copper complexes with methyl or trifluoro-substituted mono-β-diiminato ligands and one acetoxyl anion were synthesized and characterized by IR spectroscopy and elemental analysis for the first time. The structure of complex 2 bearing trifluoro substituents was further confirmed by single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1 with a = 7.377（4）, b = 11.727（6）, c = 12.913（7） ？, α = 116.569（6）, β = 98.829（7）, γ = 96.520（6）°, V = 966.2（8） ？3, Z = 2, Mr = 479.86, Dc = 1.649 g/cm3, F（000） = 482, μ = 1.205 mm-1, the final R = 0.0370 and w R = 0.0903 for 3430 observed reflections with I 〉 2σ（I）. These mono-β-diiminato copper complexes can effectively catalyze methacrylate（MA） polymerization when activated by MMAO. The introduction of fluoro groups into the N-aryl ring of β-diiminato ligands can greatly increase the catalytic activity of copper complexes as well as the molecular weight of PMA.

Comparative Studies of Some Novel Cu(II) Polymeric Complexes Derived from Cyanoacetylhydrazine (CAH;L). The Role of Solvents Used on the Structure and Geometry of the Isolated Cu²⁺Complexes

Novel polymeric Cu2+ complexes derived from the reaction of cyanoacetylhydrazine (CAH;L) with CuCl2•2H2O in different solvents were synthesized and characterized. The isolated solid polymeric complexes were investigated using modern conventional physicochemical and spectral (IR, 1H-NMR, UV-Vis. ESR, Raman), magnetic and thermal studies. The results revealed that CAH behaves in different ways towards the coordination of the Cu2+ ion. The promotion of solvents to the cyano group was discussed on the basis of the solvent and the Cu2+ ion used. Magnetic and spectral studies suggest octahedral geometry is proposed for the Cu2+ complexes. EPR studies indicate the existence of polymeric complexes depending on the results of g-values. The results suggest that the number of copper atoms ranges from three to twelve atoms. The molecular modeling is drawn and some chemical characteristics are calculated such as chemical reactivity and energy components are investigated between the different types of the ligands.

IMMOBILIZATION OF GLUCOSE OXIDASE AND CELLULASE BY CHITOSAN— POLYACRYLIC ACID COMPLEX

This study is concerned with chitosan-polyacrylic acid complex as a carrier to immobilize glucose oxidase (GOD)and cellulase. The optimum emperature of the immobilized GOD (IG) was determined to be 60℃ which is higher than that of the native GOD about 40℃. The optimum temperature of the immobilized cellulase (IC) was determined to be about 30℃ higher than that of native cellulase. Both of the optimum pH of IG and IC shifted one pH unit to acid. Immobilized enzyme may be used in more wide pH range. Their storage life are much longer compared with their native states. Both of them can be reused at least 12 times.

Synthesis and Magnetic Properties of Fe（Ⅱ） and Nd（Ⅲ） Complexes of Poly（N-2-thiazolylacrylamide）

N-2-Thiazolylacrylamide （NTA） was polymerized by a radical route to obtain the polymer in good yield. The polymer with a pendent heterocyclic group is soluble in common organic solvents, which allow to prepare the corresponding metal complexes with higher loads easily. FTIR, ^1H NMR, elemental analysis, and energy-dispersive X-Ray spectroscopy （EDX） were applied to characterize these materials. The magnetic behavior of Fe（Ⅱ） and Nd（Ⅲ） complexes of poly（N-2-thiazolylacrylamide） was examined by a PPMS-9T magnetometer, exhibiting the characteristics of a soft ferromagnet. It is found that the Nd（Ⅲ） complex has an extremely high relative saturation magnetization of 35 emu/g.

Synthesis and Characterization of a Cobalt Complex with Maleate and Pyridine

A new polymeric cobalt complex [Co(-male)(py)(H2O)]n (male = maleate; py = pyridine) 1 was prepared by cobalt chloride hexahydrate with disodium maleate and pyridine in an alcohol-aqueous solution. Single-crystal X-ray analysis has revealed that 1 crystallizes in the orthor- hombic system, space group Pnma with a = 18.001(1), b = 7.6001(6), c = 7.4731(6) ? V = 1022.4(1) 3, Z = 4, C9H9CoNO5, Mr = 270.10, Dc = 1.755 g/cm3, F(000) = 548, m(MoK? = 1.683 mm-1, S = 1.002, the final R = 0.0280 and wR = 0.0746 for 883 observed reflections with I > 2s(I). The structure analysis shows an approximate octahedral coordination environment of metal center. The Co(II) ions are bridged by maleic anions in a rare tetradentate coordination fashion with a syn-anti coplanar con- formation of the carboxyl group, forming a two-dimensional corrugated 2-D structure which is further attached into a three-dimensional framework via non-classical CH…O interactions between adjacent layers.

STUDIES ON IMMOBILIZED GLUCOSE OXIDASE BY DIETHYLAMINOETHYL CELLULOSE COMPLEXES

The properties of immobilized glucose oxidase (GOD) by the complexes of diethylaminoethyl cellulose(DEAEC) with different polymers, such as polymethylacrylic acid (PMAA), polyacrylic acid (PAA), polystyrene sulfonic acid (PSSA), polyvinylaleohol (PVA), polyethylene oxide (PEO) and styrene-maleic acid copolymer (PSMA) were investigated. The activity of immobilized GOD was obviously influenced by the component of the DEAEC complexes. The relative activity of the immobilized GOD reached to maximum and over 90% of the native GOD. when the DEAEC-PMAA DEAEC-PAA complexes were used as a carrier with the molar ratio of DEAEC and polyacid of about one. Michaelis constants (Km) of the immobilized enzymes of DEAEC-GOD-PMAA and DEAEC-GOD-PAA were determined to be 1.25 and 1.00, respectively. Moreover, the immobilized GOD has a good storage stability and cyclic life.

Synthesis and Crystal Structure of Cadmium(Ⅱ) Complex [Cd(H_2O)(CH_3OC_6H_4COO)_2]_n

At room temperature, the reaction of Cd(NO3)24H2O and anisic acid in an ethanol solution affords the cadmium (Ⅱ) complex [Cd(H2O)(CH3OC6H4COO)2]n. The crystal is of monoclinic, empirical formula C16H16O7Cd, Mr = 432.69, space group C2/c with parameters: a = 34.211(2), b = 6.030(2), c = 7.611(3) ? = 95.619(5)? V = 1562.5(9) ?, Z = 4, Dc = 1.831 g/cm3, = 1.434 mm-1, F(000) = 856, R = 0.0215 and wR = 0.0456. 1121 reflections with I ≥ 2s(I) were considered to be observed. Each cadmium atom is seven-coordinate in a distorted pentagonal bipyramidal geometry. The Cd (Ⅱ) center is doubly bridged with the neighboring Cd centers by anisate ligands to form a four-membered ring with a repeating unit of CdOCdO-. The extended structure and hydrogen-bonding patterns displayed in the complex were studied.