Research on the Synthesis and Optical Properties of Isomeric Bichromophoric Compounds --3-or 4- Phenyl 7-Coumarin ω-9-Anthracene-Poly-methene Carboxylate

Six bichromophoric compounds-substituted coumarin ω -9-anthra-cene-poly-methene carboxylate and five model compounds were synthesized. Among them, eight compounds are new ones. Intramolecular singlet energy transfer has been demonstrated in the bichromophoric compounds 1? and studied in some detail. The absorption spectra of the compounds 1-6 bear evidence that the π-electron systems of coumarin and anthracene ring do not overlap appreciably. The coumarin moiety of the bichromophoric compounds molecule was excited at 314nm and the resulting fluorescence was characteristic of the anthracene group. The efficiency of transfer of singlet excitation from coumarin moiety to the anthracene grou is about 100% in both calculation and observation and the rate of the singlet energy transfer is about 1014 sec in the compounds 4-6. A possible mechanism of intramolecular energy transfer was suggested. The difference between 4-phenyl compounds 1-3 and 3-phenyl compounds 4-6 in spectra was com -pared.     

An Efficient One-pot Synthesis of β-Amino/β-Acetamido Carbonyl Compounds via ZrCl4-catalyzed Mannich-type Reaction

Zirconium(IV) chloride catalyzed efficient one-pot synthesis of β-amino/β-acetamido carbonyl compounds at room temperature is described. In the presence of ZrCl4, the three-component Mannich-type reaction via a variety of in situ generated aldimines, with various ketones, aromatic aldehydes and aromatic amines in ethanol, led to the formation of β-amino carbonyl compounds and the four-component Mannich-type reaction of aromatic aldehydes with various ketones, acetonitrile and acetyl chloride resulted in the corresponding β-acetamido carbonyl compounds in high to excellent yields. This methodology has also been applied towards the synthesis of dimeric β-amino/β-acetamido carbonyl compounds.     

Unusual Reaction of Diazo Compounds with Enamines

Transition metal catalyzed decomposition of diazo compounds and consequent transformations constitute various synthetic useful reactions in the past decades. The catalytic addition of diazo compounds to olefins generally provides cyclopropanes in high yield. However the reaction of electron-rich enamines with diazo compounds gave variable results. Wenkert et al. reported the reaction of enamines with ethyl diazoacetae (EDA) in the presence of cuprous chloride or silver oxide unexpectedly gave…     

Ring Contraction Reaction of 4H-1,3-Oxazin-4-ones under Electrospray Ionization Conditions

Ring contraction reactions of heterocyclic compounds under mass ionization conditions are important and interesting phenomenon.[1] It should be very useful to elucidate the fragmentation of some novel heterocyclic compounds and to identify the structures of some effective compounds in a screened library by mass spectrometric method, which is an easy and available method for identification of effective members in a library due to development of LC-MS. Recently several ring contraction reactions have been reported in literatures.     

Insight of unresolved complex mixtures of saturated hydrocarbons in heavy oil via GC×GC-TOFMS analysis

The saturated hydrocarbon fraction of a heavily biodegraded crude oil from Liaohe oilfield was analyzed by using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS). The "humps", which was termed as unresolved complex mixtures (UCMs) in conventional gas chromatographic analysis, was separated for identification of the individual compound. Main compounds of UCMs were identified according to the combined information of characteristics of GC×GC chromatogram and time-of-flight mass spectra. It’s found that UCMs are mainly composed of great number of ring compounds with extremely low concentration. The ring compounds are separated according to their boiling point diversity in the first dimension column, then to their polarity or ring number variety in the second dimension column. In the sample there are two groups of UCMs, i.e., the first group compounds with boiling point lower that of C24 and the second group compounds with boiling point higher than that of C24. The first group of UCMs mainly consists of monocyclic, bicyclic and tricyclic ring compounds. The first group of UCMs is mainly composed of saturated hydrocarbons, in which the percentage of ring compounds with signal-to-noise ratio above 100 is about 75% of the total quantity of saturated hydrocarbon, while its mass is over 80% of the total saturated hydrocarbon. The second group of UCMs is mainly composed of tetracyclic and pentacyclic ring compounds, in which the percentage of UCM compounds with signal-to-noise ratio over 100 is about 17% of the total quantity of saturated hydrocarbon, and its mass is about 0.5% of the total saturated hydrocarbon. The results of this study are helpful for heavy oil developing and genesis mechanism understanding.     

An efficient chlorination of aromatic compounds using a catalytic amount of iodobenzene

An efficient method was developed for chlorination of aromatic compounds with electron-donating groups using iodobenzene as the catalyst and m-chloroperbenzoic acid as the terminal oxidant in the presence of 4-methylbenzenesulfonic acid in THF at room temperature for 24 h,and a series of the monochlorinated compounds was obtained in good yields.In this protocol,the catalyst iodobenzene was first oxidized into the hypervalent iodine intermediate,which then treated with lithium chloride and finally reacted with aromatic compounds to form the chlorinated compounds.     

The Synthesis, Reaction and Crystal Structures of Ethyltetramethylcyclopentadienylruthenium Compounds

Pentamethylcyclopentadienyl-trimethylphosphine-metal compounds play an important role in the activation studies of saturated hydrocarbons. A method to synthesize ethyltetramethylruthenium compounds was established, which started from the reaction of RuCl_3. H_2O with ethyltetramethylcyclopentadiene to give a dimer compound of 2. When 2 was reacted with different amounts of trimethylphosphine, compounds 3 [C_5Me_4EtRu(PMe_3)Cl_2] and 4 [(C_5Me_4Et)Ru(PMe_3)_2Cl] were obtained. Compound 3 is a 17-electron species which is in formula similar to Bergman's Ir compound used in hydrocarbon activation reaction, but might be more reactive because of its unsaturated electron structure. The crystal structure analysis of compounds 2, 3 and 4, showed that the ruthenium atom was coordinated in a "threeleg-piano-stool" geometry in all the three compounds. The Ru—Cl bond in 3 and 4 was lengthened, making it labile to other substitution reactions.     

铋三氟甲磺酸酯:用于一锅多组分反应合成具有生物活性的香豆素化合物的高效催化剂（英文）

A series of coumarin-chalcone hybrid compounds and coumarins linked to pyrazoline was synthesized in good yield and short time using a simple and efficient method. This method involved the one-pot reaction of salicylaldehyde, an α-ketoester and an aromatic aldehyde(in the case of the coumarin-chalcone derivatives) in addition to hydrazine hydrate(in the case of the pyrazolyl coumarins) in the presence of a catalytic amount of bismuth triflate [Bi(OTf)3, 5 mol%]. The synthesized compounds showed scavenging activity towards the free radical 2,2-diphenyl-1-picrylhydrazyl. All compounds were characterized using IR, 1H NMR and 13 C NMR spectroscopy.     

DISCOVERY OF DEHYDROXYTOCOPHEROL IN CRUDE OIL AND SOURCE ROCK,AND ITS SIGNIFICANCE

Reported here is a novel kind of biomarker compounds, dehydroxytocopherol, detected in crude oil and source rock formed in hypersaline lake environment.Mass spectra data of three homologues are given and the possible geochemical significance of these unusual compounds is discussed briefly.     

Bismuth triflate：A highly efficient catalyst for the synthesis of bio-active coumarin compoundsvia one-pot multi-component reaction

A series of coumarin-chalcone hybrid compounds and coumarins linked to pyrazoline was synthe-sized in good yield and short time using a simple and efficient method. This method involved the one-pot reaction of salicylaldehyde, an α-ketoester and an aromatic aldehyde (in the case of the coumarin-chalcone derivatives) in addition to hydrazine hydrate (in the case of the pyrazolyl cou-marins) in the presence of a catalytic amount of bismuth triflate [Bi(OTf)3, 5 mol%]. The synthesized compounds showed scavenging activity towards the free radical 2,2-diphenyl-1-picrylhydrazyl. All compounds were characterized using IR,1H NMR and13C NMR spectroscopy.     

钠硼解石碳化机理的研究

采用Ｃａ（２＋）选择电极，ｐＨ电极和电导电极对钠硼解石水溶液碳化过程进行跟踪测定。实验结果表明：反应分二步进行，反应最终结果是钠硼解石完全分解，硼全部进入溶液并大部分以Ｈ３ＢＯ３的形式存在，同时考察了温度，气流量对钠硼解石水溶液碳化结果的影响。根据碳化机理，提出了较佳的碳化条件。     

钠硼解石——水体系溶解和相平衡的研究(英)

Ulexite dissolution in water has been studied in the wide temperature range from 10℃ to 93℃ and two higher temperatures at 120 ℃ and 240 ℃. The analytical results showed that ulexite dissolved congruently from 10 ℃ to 35 ℃ and incongruently from 40 to 68 ℃. The solid component of ulexite, NaCaB₅O₆(OH)₆·5H₂O was dehydrated to form NaCaB₅O₆(OH)₆·H₂O from 50 to 68 ℃ and finally amorphous solid at 68 ℃. This amorphous solid converted into priceite at 71 ℃ and then converted completely to priceite at the boiling point(93℃) of the solution. At both 120 and 240 ℃, the dissolution of ulexite was an incongruent process. Above 120 ℃, ulexite became amorphous solid and then transformed into priceite. In addition to the solid to solid transformation, crystallization of priceite from the solution has also been observed. Based on our experimental results, mechanisms of dissolution, transformation, and crystallization of borate in ulexite-water system are discussed.     

煅烧温度对阳极氧化WO3多孔薄膜的形貌及光电化学性能的影响

采用一步式阶跃电压加压方法,在NH4F/(NH4)2SO4电解质溶液中对W片进行阳极氧化处理制备了WO3多孔薄膜,通过后续热处理温度的控制,制备了性能规律性变化的WO3多孔纳米薄膜材料.用场发射扫描电镜(FE-SEM)、X射线衍射(XRD)分析等手段考察了热处理温度对氧化钨晶体结构和形貌影响的规律,在450°C以下的煅烧温度下,薄膜保持50-100nm孔径;通过对光电化学性质、光催化降解甲基橙动力学行为的研究,考察了不同热处理温度对WO3多孔薄膜光电转换性能影响的规律.研究表明,450°C煅烧处理后的WO3薄膜在500W氙灯光源照射及1.2V偏压下,光电流密度达到5.11mA·cm-2;340及400nm单色光辐射下光电转换效率(IPCE)值分别达到87.4%及22.1%.电化学交流阻抗谱显示,450°C煅烧处理后的WO3薄膜表现出最佳的导电率及最小的界面电荷转移电阻.实验结果证明,高结晶度的多孔结构是WO3薄膜具有高光电转换效率的主要因素,控制热处理温度是实现薄膜具有高孔隙率、完整结晶度、低电阻的重要手段.     

焙烧温度对微乳液法负载铂制备的Pt-S2O82-/ZrO2-Al2O3催化剂异构化性能的影响

过微乳液法负载Pt制备了Pt-S₂O₈^2-/ZrO₂-Al₂O₃(Pt-SZA-X) 催化剂,并采用XRD、BET、FT-IR、TPR、TEM等手段对催化剂进行了表征。以正戊烷异构化反应为探针,考察了焙烧温度对催化剂异构化性能的影响。结果表明,焙烧温度对Pt-SZA-X的还原温度影响不大,但催化剂表面S含量随着焙烧温度的升高而下降;焙烧温度为600~650℃时形成O=S=O结构,此时S与催化剂载体结合比较稳定;焙烧温度为650℃时,可得到单一的ZrO₂四方晶相,焙烧温度高于650℃时,比表面积迅速降低,催化剂表面S⁶⁺流失严重。在不同温度下焙烧得到的催化剂中,经650℃焙烧的催化剂具有适宜的超强酸位和比表面积,异构化活性最高。在反应温度为230℃、反应压力2.0 MPa、氢烃物质的量比4:1、质量空速1.0 h^-1时,催化异戊烷产率达到60.8%。     

固体超强酸SO2-4/ZrO2的制备及其催化性能研究

以氧氯化锆为锆原,氨水为沉淀剂,硫酸溶液为浸渍液,通过沉淀-浸渍法制备SO2-4/ZrO2(SZ)酯化催化剂,其结构经BET、X-射线衍射(XRD)、傅立叶变换红外光谱(FT-IR)及扫描电子显微镜(SEM)表征.结果表明:随着焙烧温度升高,催化剂的比表面积依次降低,孔径增大,氧化锆的晶态由无定形态转化为四方晶态再转化为单斜晶态;于600℃焙烧时,催化剂形成的S=O键红外吸收峰最强;于700℃焙烧时,催化剂结构被破坏.在丙烯酸与十八醇的酯化反应中对催化剂进行活性测试.结果表明:600℃焙烧的催化剂产率最高(96.4%).     

Surface characterization and catalytic evaluation of manganese nodule leached residue toward oxidation of benzene to phenol

Water washed manganese nodule leached residue (WMNLR) calcined at different temperatures was characterized by XRD, FTIR, TG-DTA, surface area, surface oxygen, and surface acid sites. Surface area, surface oxygen, surface hydroxyl group, and surface acid sites increase up to 400 degrees C and then decrease with further rise in calcination temperature up to 700 degrees C. The catalytic activity of the calcined samples was tested for single-step oxidation of benzene to phenol using hydrogen peroxide as the oxidant and acetic acid as the solvent at room temperature. The influence of various reaction parameters such as solvent, concentration of solvent, oxidant amount, time, temperature, and catalyst amount was studied to optimize the reaction conditions. WMNLR calcined at 400 degrees C showed the highest catalytic activity towards oxidation of benzene with 12.7% conversion and 98% selectivity.     

ZrO2催化无溶剂条件下醇的液相氧化反应

采用一种环境友好的方法,以分子氧为氧化剂,以ZrO2为催化剂,在无溶剂的条件下实现了醇的选择性氧化.苯甲醛、环己酮和辛醛等是相应醇的主要氧化产物.考察了不同反应条件(搅拌速度、反应时间和温度)、催化剂制备参数(焙烧温度和负载量)及氧分压等的影响.结果发现,对于醇氧化生成相应羰基化合物,1 223 K焙烧的ZrO2比723 K焙烧的ZrO2显示出更高的催化活性.催化剂在反应混合物中不溶解,可以通过简单的过滤使其分离并重复使用.当搅拌速度大于900 r/min时,对醇的转化速率无明显的影响.     

CeO2掺杂的Mn/Al催化剂的物化、表面及催化性能

Pure and CeO2-doped Mn/Al mixed oxides were prepared by the wet impregnation method using finely powdered alumina, manganese, and cerium nitrates. The physicochemical, surface, and catalytic properties of the thermally treated solids (at 500, 800, and 900 ℃) were investigated using XRD, nitrogen adsorption at -196 ℃, and hydrogen peroxide decomposition in an aqueous solution at 30 - 50 ℃. The Mn oxidation state changed from Mn4 to Mn2 on increasing the calcination temperature. There were two unique features associated with CeO2 that are of interest. The first was that it favored the dispersion of manganese oxides deposited on the γ-Al2O3 catalyst calcined at 500 ℃. The second was that it enhanced the formation of Mn3O4 species from Mn2O3 deposited initially on the alumina support calcined at 800 and 900 ℃. Consequently, the specific surface area of the Mn/Al mixed oxides calcined at 500 ℃ was increased by increasing the amount of dopant added. An opposite effect was observed by increasing the calcination temperature from 500 to 900 ℃. The doping followed by calcination at different temperatures brought about an increase in the catalytic activity of mixed oxides. Pretreatments did not modify the mechanism of the catalyzed reaction but changed the number of catalytically active sites without changing the nature of these sites.     

PdO-CeO2复合氧化物催化剂的CO低温氧化

采用共沉淀法制备了一系列不同Pd含量的PdO-CeO2复合氧化物催化剂, 并考察了该催化剂的CO低温氧化反应催化性能. 运用X射线衍射(XRD), 物理吸附(BET), CO化学吸附, 程序升温还原(TPR), 脉冲反应等技术对催化剂进行了表征. XRD结果表明, 焙烧温度从400 ℃升高到800 ℃, 有利于CexPd1-xO2-δ固溶体的形成. 然而焙烧温度升至1000 ℃时, 导致Pd从固溶体中析出. 催化剂的CO氧化活性(TOF)与CexPd1-xO2-δ固溶体的含量存在一定的对应关系. 随着CexPd1-xO2-δ固溶体含量的增加, CO氧化的TOF值大, 可见CexPd1-xO2-δ固溶体的形成对CO氧化活性有着主要的贡献. 在催化剂焙烧温度相同的条件下, 催化剂的CO氧化活性与Pd粒子大小无对应关系. 脉冲反应进一步说明PdOx的CO氧化活性高于金属Pd.     

焙烧温度对合成低碳醇用Cu/Mn/Ni/ZrO2催化剂性能的影响

 研究了焙烧温度对合成低碳醇用Cu／Mn／Ni／ZrO2催化剂结构及催化性能的影响．随着焙烧温度的升高，催化剂的催化活性和产物分布都发生较大的变化．催化剂在较低的温度下焙烧，低温下反应液相产物的分布符合S－F方程；反应温度升高时，液相产物中主要是甲醇和异丁醇；在高温下焙烧的催化剂，其催化活性较低，但即使在较低的反应温度下，异丁醇在液相高级醇（C2＋OH）中也是主要的产物．结合其他的一些反应结果与XRD，BET，TPR及EXAFS等表征结果，认为焙烧温度使催化剂的结构发生了较大的变化，进而影响催化剂各组分之间的相互作用，从而使催化剂对合成低碳醇反应表现出不同的催化性能．