乙酰丙酮氧钒的绿色合成工艺研究

以三氧化二钒为钒源,在体系中引入氧化剂和水夹带剂,合成了乙酰丙酮氧钒,实现了乙酰丙氧钒的绿色连续合成。探讨了空气、过氧化氢和氧气三种氧化剂对乙酰丙酮氧钒合成的影响,对产物进行表征并与商业乙酰丙酮氧钒对比。结果表明,引入氧化剂之后,乙酰丙酮氧钒的产率显著提高,三种氧化剂制得的乙酰丙酮氧钒产率均可达到80%以上,其中氧气氧化效果最好,当氧气流量为200 mL/min,回流2 h时,乙酰丙酮氧钒产率可达90%。XRD、FTIR和TG结果显示,本研究合成的乙酰丙酮氧钒纯度较高,与商业乙酰丙酮氧钒可比。     

乙酰丙酮的合成应用及展望

乙酰丙酮又名2，4-戊二酮，是重要的医药中间体，有着极为广泛的应用。本文介绍了乙酰丙酮的物性、用途和几种制备工艺，概述了国内外乙酰丙酮的生产现状和市场需要并对今后发展提出了建议。     

乙酰丙酮的合成与应用

一、前言 乙酰丙酮(Acetylacetone)又名2,4-戊二酮或戊间二酮,结构式。纯品为无色液体,有令人不愉快的气味,低温时变为有光泽的晶体。相对密度0.976,沸点139℃(99.5Pa),熔点-23.1℃,闪点(开杯)40.56℃,自燃点340℃,折射率1.4541(17℃)。20℃时水中溶解度16.9%,能溶于酸性水,难溶于中性水,易溶于     

乙酰丙酮的合成应用及展望

乙酰丙酮又名2,4—戊二酮,是重要的医药中间体,有着极为广泛的应用。本文介绍了乙酰丙酮的物性、用途和几种制备工艺,概述了国内外乙酰丙酮的生产现状和市场需要并对今后发展提出了建议。     

三氟乙酰丙酮的合成与应用

三氟乙酰丙酮是一种重要的含氟精细化学品,由于三氟甲基酮类在结构和生物学上的独特性质,使其在医药、化工、制造、分析等领域有着多方面的应用。介绍了三氟乙酰丙酮的合成概况,并对其应用进行了详细的综述。     

乙酰丙酮钙的合成研究

以新制备的氢氧化钙和乙酰丙酮为原料,二甲苯为分散剂,合成乙酰丙酮钙,该方法的最佳工艺条件为：采用新制Ca（OH）2,乙酰丙酮／Ca（OH）2摩尔比为1．50,分散剂采用二甲苯,用量为100mL二甲苯／0．1molCa（OH）2,反应温度110℃,反应时间1h。。红外光谱表征表明,乙酰丙酮以烯醇式一价阴离子的形式与钙离子配位,形成配合物。X射线衍射（XRD）表征证明,该物质为乙酰丙酮钙。     

医药中间体乙酰丙酮的合成方法和应用

比较了乙酰丙酮各种生产工艺的缺点,重点阐述了乙烯酮法的工艺技术,对乙酰丙酮的应用范围作了说明。     

乙酰丙酮的合成及应用

介绍了乙酰丙酮的基本性质和用途,叙述了国内外乙酰丙酮的生产现状,并对各种制备方法的优缺点进行了分析。认为由醋酸裂解制乙烯酮、然后与丙酮反应制备AA的技术虽然已经趋于成熟。但在原料和产物价格适宜的条件下,也可考虑采用投资小、反应条件温和的乙酰乙酸乙酯－醋酐法;我国应在石化反应催化剂、助催化剂、溶剂和胶粘剂方面加大AA的应用研究。     

钒磷氧催化合成苯甲醛乙二醇缩醛

本文研究了钒磷氧催化苯甲醛与乙二醇的缩醛化反应 ,考察了反应时间、醛醇比、催化剂用量、带水剂用量等因素对苯甲醛乙二醇缩醛收率的影响。结果表明 ,在回流条件下 ,当苯甲醛用量为 0 .11mol,乙二醇用量为 0 .10mol,催化剂用量为 0 .0 2 5 g ,带水剂环己烷用量为 8mL ,反应 2 .5h后 ,缩醛收率可达到 71.3%。     

钒磷氧非均相催化合成苯乙酮乙二醇缩酮

研究了苯乙酮与乙二醇在钒磷氧非均相催化剂作用下的缩合反应，考察了反应时间、醇酮比、催化剂用量和带水剂用量等因素对苯乙酮乙二醇缩酮收率的影响。结果表明，在回流条件下，苯乙酮为0．10mol，乙二醇为0．12mol，催化剂用量为0．20g，带水剂环己烷用量为6mL，反应2．5h后，缩酮收率可达到81．5％，且催化剂重复使用性能良好。产品经熔点仪和红外光谱仪进行了表征。     

Polymers oxidation with VO(acac)2 complex

The introduction of epoxy groups in the polymer backbone is one of the most promising methods of modifying polydienes. In this work the performance of the classical catalytic system VO(acac)₂/tert-butylhydroperoxide was evaluated for the epoxidation of polydienes. The polymers investigated were a hydroxylated poly(butadiene), two polybutadienes with high and with low 1,4-content, a poly(isoprene), and a styrene–butadiene copolymer. The epoxidized polymers were characterized by IR, ¹H and ¹³C NMR and GPC techniques. The vanadium system was active for the epoxidation reaction and the reactivity decreases in the order HTPB>PI>1,4-PB>1,2-PBSBR. The occurrence of secondary reactions to low extension could be detected by the presence of hydroxyl, carbonyl and alcohol signals in the spectra of epoxidized polymers. Incomplete mass recovery (70–90%) was observed probably due to the chain degradation or modification of the polymer polarity.     

The Adsorption of VO(acac)2 on a Mesoporous Silica Support by Liquid Phase and Gas Phase Modification to Prepare Supported Vanadium Oxide Catalysts

Supported vanadium oxide catalysts are prepared by adsorption and subsequent calcination of the vanadyl acetylacetonate complex on silica by liquid phase and gas phase modification. The influence of the pretreatment temperature and the effect of the solvent in the liquid phase are discussed. Two types of gas phase deposition processes are used: flow-type reactions and vacuum deposition. The bonding mechanism, the influence of pretreatment temperature of the support and the influence of the reaction temperature are investigated by FTIR, XRD, TGA and chemical analysis. After calcination the obtained vanadium oxide layer is characterized by XRD and UV-Vis diffuse reflectance spectroscopy. The gas phase modification enables the creation of well dispersed supported VO_x catalysts. Loadings up to 1.4 mmol g^-1 (7 wt% V) without the formation of a crystalline fraction can be achieved. The selective oxidation of methanol to formaldehyde is used as a probe reaction to assess the catalytic activity and selectivity of the catalysts. It is shown that not the concentration of vanadium species, but their surface configuration is the determining factor in catalytic reactions.     

Multistep synthesis of VO2 (M) nanoparticles and their application to thermochromic hybrid films for IR modulation

Vanadium dioxide (VO₂) is widely known as one of the excellent thermochromic materials based on a reversible insulator-to-metal phase transition upon temperature change. In this study, VO₂ (M) powder was initially synthesized through a hydrothermal method and a subsequent post-annealing treatment. Additionally, a particle size of the VO₂ (M) powder was reduced and uniformized by introducing a ball-milling process. The resultant VO₂ (M) nanoparticles (NPs) were dispersed in ethanol with the addition of polyvinylpyrrolidone (PVP). The ethanolic dispersion was then coated on a transparent heater used as a substrate by spin-coating to produce VO₂ (M)/PVP composite films. We have attained an exact temperature control of the films by applying voltages to the heater for the assessment of their thermochromic performance such as the solar and the infrared modulation ability. For example, the film temperature could be raised from room temperature to 85.5°C within 180 s at a low voltage of 11 V, which was enough for inducing the phase transition of the VO₂ (M) NPs showing the infrared modulation ability of 19.3%. The combination of the composite films and the heater was thus proved to be a promising way for realizing transparent thermochromic devices.     

PS负载acac系列钼配合物的合成、表征及其催化性能

以二乙烯苯交联的大孔聚苯乙烯树脂(PS)为载体,首次制备了高分子配体PS-(OCH2CH2)n-acac(n=0,1,2),并在其上组装入了Mo活性中心而成为催化剂--PS-(OCH2CH2)n-acac-Mo(n=0,1,2);用红外光谱分别对高分子配体及催化剂的结构进行了表征.XPS表征证实催化剂中钼以Mo(Ⅵ)价态存在,此外还对催化剂可能存在的结构进行了分析.实验检测了PS-(OCH2CH2)n-acac-Mo (n=0,1,2)在以n(t-BuOOH)=0.1 mol计,n( (◇)):n(t-BuOOH)=3:1,溶剂用量～10 mL,反应温度～80℃,时间～60 min条件下的催化性能.结果表明,在大孔PS载体上,活性组分与载体间增加2个-(OCH2CH2)-距离的臂长,对催化剂催化性能无明显影响;PS-(OCH2CH2)n-acac-Mo催化剂(n=0,1,2)催化环己烯环氧化活性和选择性优异,其中以PS-acac-Mo催化剂最优,环氧环己烷收率在99.5%以上.用于环己烯环氧化反应经循环使用5次后,t-BuOOH转化率仍高达99%以上,催化选择性并未发现明显减低,仍保持在99%以上.     

VO(H_2PO_4)_2热分析研究

运用ＴＧ、ＤＴＡ,研究了ＶＯ（Ｈ２ＰＯ４）２在流动空气气氛中的热反应行为、非等温反应动力学和热效应。ＶＯ（Ｈ２ＰＯ４）２从６０９Ｋ开始失重,到６９５Ｋ失重完毕,失重率为１４．０１％,失重后的产物为ＶＯ（ＰＯ３）２。运用Ｓｈａｒｐ法、Ｃｏａｔｓ－Ｒｅｄｆｅｒｎ法和Ｄｏｙｌｅ－Ｚｓａｋｏ法对基础实验数据进行分析,推断出该热分解反应机理为成核和生长（ｎ＝１）,动力学函数为Ａｖｒａｍｉ－Ｅｒｏｆｅｅｖ方程;非等温热分解反应动力学方程：ｄα／ｄＴ＝Ａ／βｅ－Ｅ／ＲＴ（１－α）;动力学补偿方程：ｌｎＡ＝０．１８１Ｅ－４．６８ｂ;热分解反应转变热为０．２９１ｋＪ·ｇ－１。     

In(acac)_3和Sn(acac)_2Cl_2的合成及表征

介绍了化学法制备氧化铟锡(ITO)纳米材料的两个重要合成原料In(acac)3和Sn(acac)2Cl2的合成方法。以InCl3·4H2O为原料,在pH值为9.0的柠檬酸溶液中制备In(acac)3;以SnCl4·5H2O与乙酰丙酮为原料,在甲苯溶剂中加热回流制备Sn(acac)2Cl2。通过IR、NMR、XRD检测手段对合成的产物进行表征分析。讨论了各种实验条件对合成反应的影响,总结出In(acac)3的最佳合成条件是:柠檬酸浓度为84 mmol·L-1,pH值为9.0;制取Sn(acac)2Cl2的最佳溶剂是甲苯。     

Cr掺杂VO2(B)正极材料的合成及其电化学性能

采用水热反应法,在合成过程中通过向反应体系中添加Cr（NO₃（₃·9H₂O,制备出了Cr掺杂的VO₂（B（。结合XRD、XPS、FESEM、EDS和FTIR等表征手段,研究了不同掺杂量对目标产物物相、结构和形貌的影响。电化学性能研究表明,当掺杂量（原子百分比,下同）为0.49%时,VO₂（B（正极材料具有最佳的可逆容量和循环稳定性,其在电流倍率为0.1C时,样品的首次放电比容量为282 mA·h·g^-1,较未掺杂样品高出36 mA·h·g^-1,50次循环后,其放电比容量仍高达189 mA·h·g^-1,容量保持率为67%,明显优于未掺杂样品（60.6%）。EIS和CV研究显示,当掺杂量为0.49%时,VO₂（B（电荷转移电阻和电化学反应极化明显降低,此进一步诠释了其优异的电化学性能。     

双(三氯甲基)碳酸酯的合成及在“三药”合成中的应用

本文介绍了双(三氯甲基)碳酸酯(简称BTC)的制备方法及其在有机合成中的应用。BTC作为剧毒的光气和双光气在合成中的低毒替代物,在制备一些重要类型有机化合物时,其反应条件温和,选择性好,收率高。     

Polymerization of methyl methacrylate with Ni(acac)2–methylaluminoxane catalyst

Polymerization of methyl methacrylate (MMA) with nickel(II) acetylacetonate [Ni(acac)₂] in combination with methylaluminoxane (MAO) was investigated. Ni(acac)₂ was found to be an effective catalyst for the polymerization of MMA. From a kinetic study of the polymerization of MMA with the Ni(acac)₂–MAO catalyst, the overall activation energy was estimated to be 15 kJmol⁻¹. The polymerization rate (R_p) was expressed as follows: R_p = k [MMA]^1.0[Ni(acac)₂–MAO]^0.6 (the MAO/Ni mole ratio was kept constant). The mechanism for the polymerization of vinyl monomers with the Ni(acac)₂–MAO catalyst is discussed. © 2000 Society of Chemical Industry