Nanostructure perovskite-type LaFeO3, LaMnO3 , LaCoO3 and oxideα-FeO3 were successfully synthesized by Stearic Acid Gel Combustion, where the stearic acid was used as chelating agent and fuel. The obtained samples were characterized by FTIR, XRD, SEM and BET techniques and their photocatalytic activities for TNT degradation were studied.The experimental results showed that LaFeO3 andα-Fe O3 were directly obtained by combustion of stearic acid gel, but LaMnO3 and LaCoO3 were obtained by additio- nal calcinations treatment. The particle sizes of LaFeO3, LaCoO3 andα-Fe O3 are about 50nm, 0nm and 30nm, respectively, and their specific surface areas are 8.3 m2/g, 22.23m2 /g and 63.4m2/g, respectively, which are higher than that recorded in literatures prepared by citrate acid or chemical coprecipitation method. But the particle diameter of LaMnO3 is 0.5μm that is lager than those of LaFeO3, LaCoO3 andα-Fe2O3.In addition, taking LaFeO3, LaMnO3 and LaCoO3 as catalysts, we obtained the optimal reaction conditions. Adsorptive equilibrium time is about 30 minutes and the amounts of all used catalysts’amounts are 0.001mol. Compared with the other perovskite-type oxides （i.e. LaMnO3 and LaCoO3）, LaFeO3 has the best photocatalytic activity which was further proved by UV-Vis DRS spectrogram.For LaFeO3 catalyst, a variety of the factors that influenced in TNT degradation progress were investigated. Of all the initial concentrations of TNT, 20mg/L TNT could be rapidly degradaed in the alkaline conditions, the optimal reaction time was 60 minutes, and the photocatalytic reaction could be expressed as the first order . After reusing, LaFeO3 still had good photocatalytic activity.A comparision of LaFeO3 withα-Fe2O3 showed that the oxygen and hydroxyl absorbed were probably the main active sites of LaFeO3 catalyst. Through the UV spectrogram, the possible pathway of TNT degradation was disscussed. First, methyl group was removed from TNT, then the nitro group which was difficult to oxide was reduced to amine group, finally, the aromatic compounds degraded into small organic molecules.
Post about "2"
Hydrogen-Bonded Self-assembling Supramolecular Poly(Isobutylene-co-p-methylstyrene-co-p-bromomethylstyrene)
Recently the self-assembling technique based on hydrogen-bonding is playing a more and more important role in the preparation of polymer materials.Non-covalent hydrogen-bonding was introduced into Butyl Rubber via the reaction of poly(isobutylene-co-p-methylstyrene-co-p-bromomethyl -styrene)(BIMS)with 3-amino-5-acetamino-1,, (AAYA).Reaction of poly(isobutylene-co-p-methyl-styrene-co-p-bromomethylstyrene)(BIMS) with 3-amino-5-acetamino-1, , (AATA)was carried out with the phase transfer catalyst.The ~1H-NMR spectroscopy of BIMS,which was substituted by AATA,indicates that the reaction underwent a mechanism of the substitution of Br.The substitution of Br and the microstructure were determined by ~1H-NMR spectroscopy and the existence of hydrogen-bonded crosslinking was confirmed by the viscosity increase of the BIMS substituted by AATA.However,the substitution of Br was not fully completed.The effects of reaction time,temperature,the amount of AATA, the category of BIMS and the amount of water on the substitution of Br in BIMS by AATA were investigated.The results show that under the conditions of 70℃,12 hours,tertrabutyl ammonium bromide as a phase transfer,and 4/1(mol/mol)as the monomer ratio of AATA/Br,the substitution of Br reaches a higher level.
In the paper,tetrafluorobenzene with four different substituents,such as amidine cyano nitro hydroxyl,were synthesized., , , is an important intermediate for medication and pesticide industry. can be used as raw material for synthesis special effective medicine which has good effect on anti-phlogistic and anti-depression.While , , , has great market demand as the medicine intermediate and the liquid crystal material intermediate.we use ,3, ,6-tetrafluorobenzoic acid as raw material 2,3,5,6-tetrafiuoroaniline 2,3,5, In the paper,we synthesized 2,3,5, and 2,3,5,6-tetrafluorobenzonitrile take 2,3,5,6- tetrafluorobenzoic acid as the foundation raw material,synthesis condition of laboratory was studied,which provided the basis for in-depth research and industrial production.This topic belongs to pharmaceutical intermediates research field.There are mainly four aspects of the experiment part of this paper.Firstly, 2,3,5, was synthesized by and the optimum reaction conditions was determined.Secondly,the dynamics of was studied,the activation energy of the Hoffman degradation reaction of 2,3,5,6-tetrafluorobenzoyl amine was determined.Thirdly,2,3,5,6-tetrafluorobenzonitrile was synthesized and the optimum reaction conditions was determined.Fourth,2,3,5,6-tetrafluoronitrobenzene was synthesized; fifthly,2,3,5,6-tetrafluorobenzonitrile was synthesized and the optimum reaction conditions was determined.The results show that:first,in the synthesis of 2,3,5,6-tetrafluoroaniline,the molar ratio of 2,3,5,6-tetrafluorobenzoyl amine,sodium hydroxide and sodium hypochlorite is 1:2:1, the temperature of rearrangement reaction is 0 to 5℃,the temperature of hydrolysis reaction is 70 to 75℃,the time of hydrolysis and decarboxylation is 1 h.The total mass yield of was 76.5%,the purity of the product＞98%.Second,The dynamics of Hoffman degradation reaction was determined during 0℃,20℃,30℃,from the curve we concluded that the order of the reaction is n=1,activation energy Ea=5.42×103 J/mol.Three,in the synthesis of 2,3,5,6-tetrafluorobenzonitrile,2.4g 2,3,5,6-tetrafluorobenzoyl amine,25ml chlorobenzene was used,the molar ratio of thionyl chloride and 2,3,5,6- tetrafluorobenzoyl amine is 1.3:1,thionyl chloride was dropped at 90℃,keeping refluxing for 3 h,obtained 1.49 g,2,3,5,6-tetrafluorobenzonitrile,the yield of was 68%.Four,2,3,5,6-tetrafluoronitrobenzene was synthesized from2,3,5,6-tetrafluorobenzoic acid by nitration and decarboxylation,the yield of was 64.6%five,the optimum reaction condition of synthese 2,3,5,6-tetrafluorophenol by phase transfer catalytic method is 3.36 gram of Pentafluorobenzene,6.44 gram of （Bu）4N+HSO4-,1.6 gram of 50%w/w NaOH solution,and 25 mL of cyclohexane as solvent.The reactions were carried out for two hourses,the yield is 65%.In this paper,the structure of the intermediate products,the final product and other related compounds were characterized.
With the extensive use of pyridine and its derivatives in medicine and pesticide industry, the synthesis of these compounds become the focus of research and development in the Fine Chemical Intermediates preparation and package service. On one hand, the preparation technology of pyridine base and part of its derivatives have been becoming more and more mature and there are exuberant demands of them; on the other hand, these heterocyclic compounds bring out great pressure to the environment.Therefore, in the papers, we aimed to find out away for several typical pyridine base derivatives, considering the replacement of raw materials, solvents and reagents, the optimization of reaction processes and atom economy. As a result, we chose -chloropyridene as the raw material to synthesis -chloro-4-nitro pyridine and -chloro-4-aminopyridine, selected sulfuric acid as the catalyzer and 30% hydrogen peroxide as the oxidant instead of 50% hydrogen peroxide, which guaranteed well yields and good stability of the technology. Moreover, the amount of acetic acid, using as the solvent, had been reduced from 10 times equivalent to 3～5 times. In the reduction process, we investigated the effectiveness of Raney Ni and hydrazine hydrate and gained ideal results in small experiments. Then we chose ethyl nicotinate as the raw material to synthesis 3-pyridinioacetate, correcting the conception that using high cost nicotinic acid to synthesis ethyl nicotinate. Our optimized method, which was suitable for scale-up, was much milder in the acidolysis and decarboxylation of ketonic acid ester intermediates, and realized solvent emission reduction through reusing extractants. At last, we chose 2,3,5-trimethylpyridine as the raw materials to synthesis 2-chloro-methyl-3,5-dimethyl-4- methoxylpyridine, chose 2,3-dimethyl pyridine to receive ,2,2- trifluoroethoxy) -pyridine, and chose furan to gain 2-chloromethyl -3, . In the process, we selected boron trifluoride as the catalyzer in the Friedel-Crafts reaction, optimized the oxidation reaction according to the preparation of , and discussed the mechanism and application of Bockethide reaction and the mechanism and influence factors in the synthesis of pyridine from furan. On the basis of the previous work, we designed synthesis routes for three kinds of prazoles. By small experiments, with certain sacrifice of yield, we had found out the optimum ratio of raw materials, which improved the production efficiency. Besides, we replaced highly toxic raw materials, such as dimethyl sulfate and potassium cyanid and characterized ~1HNMR of relative compounds.
, （ ,6-DMN）is a precursor of ,6-naphtalene dicarboxylic acid in the manufacture of high performance polyester resins such as polyethylene naphalate polymer（PEN）.PEN is too expensive to expand its market completely because of few effective processes for 2,6-DMN commercialization.Therefore, has become an important subject to find an efficient process for 2,6-DMN synthesis to promote application of PEN.A shape-selective zeolite catalytic process for 2,6-DMN synthesis by of 2-methylnaphthalene was implemented in this paper.The of 2-MN over （SiO2/Al2O3=83）was investigated in a fixed-bed flow reactor under the pressure of 3MPa.The main influence factors of reaction performance have been taken into account.For example,temperature,WHSV and molar ratio of feed flow. The feed flow has three components,2-MN,methanol and 1,3,5-TMB。According to the conclusion,the optimized reaction conditions under 3MPa is WHSV=2h-1,temperature360℃and molar ratio of feed flow=1:2:5.After the comparison of and HM,hydrothermal treatments were employed on HM zeolite under different temperatures.Hydrothermal treatment is an important modified way for catalysts,can better the catalytic performance.Campared the reaction capability over HM with different hydrothermal treatment temperature,500℃was the best.Acid leaching was employed over the HM zeolite which had been hydrothermal treated, increased the percents of meso-pore structure.Consolidate with the effect of 1,2,4-TMB as solvent,we better the conversion of 2-MN and selectivity of 2,6-DMN.The reaction implemented in the air of H2,the catalyst showed a slower deactivation velocity,kept the stability of reaction.After 5h reaction,the conversion of 2-MN was 27.1%,the selectivity of 2,6-DMN was 48.8%and the yield of 2,6-DMN was as high as 5.1%.
Synthesis of Thiadiazine、Thiosemicarbazide、Thiadiazole Derivatives Containing Benzimidazole under Microwave Irradiation
The application ofin organic synthesis develope very fast, since 969, the first time the technology used in organic reactions by American scientist Vanderhoff. The characteristic of microwave irradiation is that can heating reaction substrates in a very short time, this heating method can make these reactions which can not proceed on conventional heating processes taking place. Microwave technology has a wide application prospect in all branches of chemistry, biotechnology and environmental protection.Benzimidazole moiety displays a broad spectrum of biological activities including antiviral, antifungicide, anti-inflammatory effects, some benzimidazole compounds have found applications in diverse therapeutic areas for hypertension and ulcer. As an active center functional group of some enzymes, benzimidazole scaffold takes part in many signficant biochemical processes and paly an important role in biological activities. , , ,4-b]- 42;, ′,4′-thiadiazine, thiosemicarbazide, 1, , heterocyclic compounds also exhibits high biological activities, such as anti-inflammatory, analgesic, antibacterial, inhibit microorganism, antiviral and regulation of plant growth.In order to realize combination of multiform active ingredients, we designed and have synthesized a series of novel thiadiazine, thiosemicarbazide and 1, , derivatives which containing benzimidazole compounds in order to enhance their biological activities. extended the research field of such compounds and provided abundant leading compounds for later selecting work of effective drugs.This thesis consists of two major parts:The first part is about literature review. The progress in application and synthesis of , thiadiazine, thiosemicarbazide, thiadiazole derivatives and the principle of microwave irradiation and ’s application in organic reactions were systematic exposition.The second part is about experimental content. Major work as follows:1. A series of novel 1,2, ,4-b]- 1′,3′,4′-thiadiazine derivatives were synthesized by the reaction of 3-(2-substituted -1-methylene)-4-amino-5-mercapto-1,2, 4-triazole withα-bromoacetophenones under microwave irradiation and heating. Comparison of the conventional refluxing method and microwave irradiation accelerate means, discussed for the results; 2. A series of novel 1-(2-trifluoromethylbenzimidazol-1-acetyl)-4-aroylthiosemicarbazide were synthesized by the reaction of 1-(2-trifluoromethylbenzimidazole-1-yl)acetyl hydrazine with aroylisothiocyanate under microwave irradiation and heating.The preliminary biological activity of the target compounds have been tested;3. 1-(2-trifluoromethylbenzimidazol-1-acetyl)-4-aroylthiosemicarbazide were synthesized under microwave irradiation. Then compounds were cyclized in acetic acid to afford a series of novel 2-aroylamino-5-(2-trifluoromethylbenzimidazol-1-ylmethyl)-1,3,4-thiadi- azole in excellent yields under microwave irradiation. Comparison of the conventional refluxing method and microwave irradiation accelerate means, discussed for the results.The innovations of the paper are based on the follow:1. 3-(2-methyl benzoimidazole-1-methylene)-6-aryl-7H-1′,2′,4′-triazolo[3,4-b]-1″,3″,4″- thiadiazine and 3-(2-trifluoromethyl benzoimidazole-1-methylene)-6-aryl-7H-1′,2′,4′ -triazolo[3,4-b]-1″,3″,4″-thiadiazine were synthesized unreported in the literatures under microwave irradiation. The conditions of microwave irradiation were discussed;2. A series of novel 1-(2-trifluoromethylbenzimidazol-1-acetyl)-4-aroylthio-semicarbazide were synthesized under microwave irradiation. The preliminary biological activity of the target compounds have been tested, the result show that compound 2a have some anti-HIV-1 reverse transcriptase activity;3. Ten 2-aroylamino-5-(2-trifluoromethyl-benzimidazol-1-ylmethyl)-1,3, were synthesized under microwave irradiation, ten precursor compounds were synthesized under microwave irradiation too. After two steps of the microwave irradiation, high purity products were obtained.
, is an important chemical material and pharmaceutical intermediate. could be used in the synthesis of a number of fine chemicals including Pharmaceuticals, pesticides, dyestuffs, surfactants, etc. , could be obtained by reduction of 3,6-dimethyl-2,5-diketopiperazine、2, or catalytic hydrogenation of lactamide or . In this thesis, was used as reactant to form 2,5-dimethylpiperazine in the presence of hydrogenation-dehydrogenation catalysts, e.g. . The reaction conditions were optimized, such as the amount of the catalyst、reaction temperature、reaction pressure and reaction time. The optimum processing conditions: 2.0～3.0 MPa original hydrogen、reaction temperature 150～170℃, 2.5～5.0 grams of catalyst per mole and a reaction time of 4 to 6 hours. Under these conditions, the conversion of was 100 % and the yield of 2,5-dimethylpiperazine was about 70%. The reaction conditions were much moderate compared to references, e.g. the reaction pressure drop from 8.0 MPa to 4.0 MPa and the reaction temperature drop about 50℃. Reaction with 、 with addition of Mo and Cu/SiO2 were also studied. But all of the yields and coversion were much lower. 2,5-dimethylpiperazine, which purity was 90%, was obtained by rectification. And 2,5-dimethylpiperazine of 99 % purity was got by recrystallization. The result ratio of 2,5-dimethylpiperazine against 2, could be regulated according to reaction temperature, initial pressure, etc. For example, 2,5-dimethylpyrazine could be obtained by a high yield of 74.5% when reacting at 240℃for 6 h with 1.25 g·mol-1 Raney Ni catalyst and zero initial pressure.
The main purpose of this paper is to modify supportedcatalysts through their reaction with some specific organic compounds,in order to alter the nature and distribution of the active sites（C*）,thereby control the chemical composition distribution（CCD）of ethylene-α-olefin copolymers（or:linear low density polyethylene, ）.Firstly,an industrial supported catalyst（cat-1）is modified by treating with ,6 11; diisopropyl phenol,getting the modified catalyst cat- .The two catalysts were used for ethylene and 1-hexene copolymerization in different comonomer concentration.The copolymers were characterized by 13C-NMR and GPC.Experimental study found,comonomer effect of cat-2 is weaker than cat-1. In copolymerization with cat-2,the activity reached the maximum value at relatively low 1-hexene concentration.With increasing comonomer concentration, the molecular weight of copolymer catalyzed by cat-2 declines much slower than cat-1.13C-NMR analysis showed that the copolymer catalyzed by cat-2 is more uniform in comonomer distribution than copolymer catalyzed by cat-1,especially the catalytic system activated by MAO.Secondly,a supported catalyst TiCl4/MgCl2（cat-3）was prepared, then was modified by 2,6 – diisopropyl phenol,getting the modified catalyst cat-4.The two catalysts were used for ethylene and 1-hexene copolymerization and copolymerization in the presence of a small amount of hydrogen.The copolymers were characterized by 13C-NMR and GPC.The experiment results showed that, comonomer effect of cat-4 is weaker than cat-3,as revealed by 13C-NMR analysis of the copolymer’s soluble and insoluble fractions in boiling n-heptane,the 1-hexene content in the two fractions is much closer in copolymer catalyzed by cat-4 than cat-3,so the copolymer by cat-4 has more uniform comonomer distribution,especially the catalytic system activated by MAO.The decline of activity with hydrogen amount in the polymerization with cat-4 is slower than with cat-3.In the presence of hydrogen,the copolymer catalyzed by cat-4 also showed a more uniform comonomer distribution than cat-3,especially when the catalytic system was activated by MAO.In general,these changes are beneficial to the synthesis of ethylene-α-olefin copolymers with narrower distribution of composition.1-Hexene homopolymerization catalyzed by cat-3 and cat-4 were also studied. The number of the active（Cp）center in the catalytic systems was determined using a method based on quenching reaction by cinnamoyl chloride.The average polymerization activity of active sites of cat-4 is less than cat-3,maybe some active site in cat-3 catalyst is deactivated by 2,6 – Diisopropyl phenol.When adding a small amount of hydrogen to 1-hexene homopolymerization system,Cp of all the catalytic systems decreased,in which cat-4 reduced more significantly.Based on the main results of this work,the mechanism of catalyst modification by phenoxy ligand was discussed,and two possible models of the interaction between the phenoxy ligand and the active centers were proposed.
The present thesis relates to theof 42;-O-benzoyl-5′-O-（4,4′-dimethoxytrityl） N4-acetyl-2′,3′-secocytidine and 2′-O-benzoyl-5′-O-（4,4′-dimethoxytrityl）-N2-isobutyryl-2′,3′-secoguanosine. They are an important intermediate for the preparation of oligonucleotide. So the research on of the nucleoside derivatives was of great practical significanc. The final products were identified by IR and 1H NMR.The synthesis of 2′-O-benzoyl-5′-O-（4,4′-dimethoxytrityl）-N4-acetyl-2′,3′-secocytidine comprises the following steps: DMT-Cl（4,4′-dimethoxytritylchloride） reacted with N4-acetylcytidine in prydine is converted to 5′-O-（4,4′-dimethoxytrityl）-N4-acetylcytidine, which is oxidated by NaIO4 and reductived by NaBH4 to give5′-O-（4,4′-dimethoxytrityl）-N4-acetyl-2′,3′-secocytidine. Acylatel with benzonychloride affords final product in the total yield 41%.Preparation of the 2′-O-benzoyl-5′-O-（4,4′-dimethoxytrityl）-N2-isobutyryl-2′,3′-secoguanosine starts from guanosine. is acylated by isobutyryl chloride provide N2-isobutyrylguanosine. DMT-Cl reacted with N2-isobutyrylguanosine in prydine is converted to 5′-O-（4,4′-dimethoxytrityl）-N2-isobutyrylguanosine, which is oxidated by NaIO4 and reductived by NaBH4 to give 5′-O-（4,4′-dimethoxytrityl）-N2-isobutyryl-2′,3′-secoguanosine. Acylatel with benzony chloride affords the key intermediate is formed in 28% yield.
Syntheses, Characterization, Structure and Properties of Complexes with Terpyridine and Terpyridine-like Ligands
One of the most important used in modern coordination chemistry is the aspect of N-heteroaromatic ligands, which largely based on pyridine,, ′-bipyridine, , and 2,2′:6′,2″-terpyridine （simply terpyridine）, have become an ever-expanding synthetic, application and structural frontier. Terpyridine ligands and the tailored terpyridine derivatives （especially 4′- functionalized terpyridines） are stronge tridentate ligands and have much advances and ever-expanding potential applications. Their well-known characteristics are applied in the fields of optical, catalytic, molecular recognition, gas storage, solar cell and so on. Also they could self-assemble lots of intriguing topological structures.Firstly, this thesis focuses on the of three 4′- functionalized terpyridine with 4-hydroxyphenyl、2-furyl and carboxylic acid. Several coordination compounds have been prepared by the reaction of d10 metals (Cd2+、Zn2+) with these ligands. All compounds are characterized by elemental analysis, IR, emission spectra and single-crystal X-ray diffraction.On the other hand, we think and 2,6-bis（2-furyl）pyridine are very useful terpyridine-like ligands. Three novel melamine complexes with copper（II） including sandwich and extensive hydrogen bonds were obtained. Moreover, a new ligand of 4-（4′-Hydroxyphenyl）-2,6-bis（2-furyl）pyridine has been synthesized and may be uesd as pH sensor.In detail, the work is divided into six chapters as following:In Chapter 1, the research background of the of 4′-functionallized terpyridine and the current survey of terpyridine coordination compounds in particular optical properties and supermolecular assemblies are concisely introduced. A survey of melamine and 2,6-bis（2-furyl）pyridine are also mentioned.In Chapter 2, the cadmium（II） complex, Cd（p-HO-ptpy）Cl2, p-HO-ptpy being a tridentate ligand 4′-（4-hydroxyphenyl）-2,2′:6′,2″-terpyridine has been synthesized and the crystal structure is determined using X-ray crystallography. Furthermore, its luminescent and electrochemical properties compared with the ligand have been investigated.In Chapter 3, the cadmium（II） complex, [Cd（ftpy）I2]·CHCl3, which ftpy being a ligand of 4′-（2-furyl）-2,2′:6′,2″-terpyridine has been synthesized. Furthermore, its crystal structure and luminescent properties compared with the ligand have been investigated.In Chapter 4, five mononuclear complexes c1-c5 and a mononuclear polymer c6 containing the ligand of 2,2′:6′,2″-terpyridine-4′-carboxylic acid （Hctpy） were prepared by hydrothermal method. The metallic ions in c1-c5 have distorted octahedral coordinations with six nitrogens from two molecules of Hctpy. But 1D chain structure of complex c6 is built by carboxylic acid of Hctpy and resulted in the enhanced emission band. The coordination mode of c6 has never been reported.In Chapter 5, a new ligand of 4-（4-Hydroxyphenyl）-2,6-bis（2-furyl）pyridine had been synthesized by two methods. Furthermore, this compound exhibits novel ultraviolet and electrochemical properties under the influence of pH value. The reason and the mechanism of Hpfpy may be tentatively assigned.In Chapter 6, three copper（II） coordination compounds have been synthesized and researched by cyclic voltammograms. Two novel melamine coordination compounds of them including the copper directly bonded to the aromatic rings of melamine have extensive hydrogen bonds and consolidate a 2-D sheets. Interestingly, one is a dinucear complex with a paddle wheel structure in which the apical positions are occupied specially by two different donor ligands.