Dawson结构磷钨酸镧催化绿色合成己二酸

通过复分解法制备出Dawson结构磷钨酸镧(La H3P2W18O62·n H2O),采用FT IR、SEM对其进行了表征,并将其用于催化30%H2O2氧化环己酮合成己二酸。考察了其用量、30%H2O2用量、反应时间、反应温度及重复套用次数对己二酸收率的影响。结果表明,自制磷钨酸镧具有Dawson结构,呈椭球状。优化合成工艺条件为:n(环己酮)/n(30%H2O2)=100/500,w(磷钨酸镧)=6.4%(基于环己酮的质量),反应温度100℃,反应时间5.5h。优化反应条件下,己二酸的收率最高可达86.5%。磷钨酸镧重复套用5次,己二酸收率仍可保持为74.1%。     

磷钨酸-有机酸性助剂催化氧化环己酮合成己二酸

以磷钨酸-有机酸性助剂为催化体系,催化30%H2O2氧化环己酮合成己二酸。环己酮100 mol,n(磷钨酸)∶n(有机酸性助剂)∶n(环己酮)∶n(H2O2)=1∶10∶400∶2 000时,使用有机酸性助剂调节磷钨酸催化活性,结果表明以磷钨酸-酒石酸钾钠氧化环己酮效果最优,反应8 h时己二酸分离产率达93.1%;单独以磷钨酸为催化剂时,产率62.5%。以4-氨基安替比林或酒石酸钾钠为有机酸性助剂时,随反应时间的延长,产率一般会升高。磷钨酸-酒石酸钾钠和磷钨酸-4-氨基安替比林催化体系重复使用5次后,产率仍分别达到87.1%和80.6%。     

Dawson结构磷钨酸银催化绿色合成阿司匹林

通过沉淀法制备出Dawson结构磷钨酸银(Ag3H3P2W18O62·n H2O),采用FT IR、EDX对其进行了表征,并将其用于催化乙酸酐和水杨酸合成阿司匹林。研究了催化剂用量、水杨酸和乙酸酐摩尔比、反应温度、反应时间等因素对反应的影响。结果表明,所制磷钨酸银在多次使用后仍保持Dawson结构不变。在优化条件下,即n(水杨酸)∶n(乙酸酐)=1∶1.75,反应温度为90℃,催化剂用量为3.2%(以反应物质量计),反应时间为20min,阿司匹林收率为90.1%。催化剂重复使用5次,阿司匹林收率仍可保持为82.4%。     

wo3催化h2o2氧化环己酮合成己二酸

以WO3为催化剂,在无有机溶剂和相转移催化剂的情况下,用H2O2氧化环己酮合成己二酸。探讨了催化剂用量、H2O2用量、反应温度和时间等条件对反应的影响。在优化条件下:n(环己酮)∶n(H2O2)∶n(WO3)=100∶500∶2,反应温度为120℃,反应6 h,己二酸分离收率可达80.3%,纯度为99.8%;催化剂重复使用5次后己二酸收率仍可达70.2%。     

Dawson型磷钨钼杂多酸的制备及其对H2O2氧化环己酮制己二酸的催化

采用水热法制备了新型H6P2W9Mo9O62.24H2O催化剂,并用UV-Vis、FT-IR和TG-DTA等测试技术对催化剂进行了表征。以微波促进30%过氧化氢氧化环己酮制备己二酸合成反应为探针,考察了催化剂的催化性能。通过正交实验探讨了几种因素对反应的影响,确定了优化工艺条件为:n(环己酮)∶n(过氧化氢)∶n(草酸)∶n(催化剂)=100∶400∶1.25∶0.25,反应温度100℃,微波辐射功率400 W,反应时间3.5 h,己二酸产品的收率达87.33%,纯度可达99.7%。反应结束后,将反应后含催化剂的溶液浓缩至一定浓度,催化产率降低,重复使用5次收率降低为45.89%。     

回收灯用钨丝在H2O2催化氧化环己酮合成己二酸中的应用

以回收灯用钨丝为催化剂前驱物,30％H2O2为氧源,催化氧化环己酮合成了己二酸,反应体系中无须使用有机溶剂、酸性助剂和相转移剂。 IR和TG分析表明,钨丝与H2O2反应生成的新生态过氧钨酸是催化活性成分,合成己二酸后转化为钨酸。 钨丝为催化剂前驱物合成己二酸适宜反应条件为：100 mmol环己酮,50 mL 30%H2O2,钨丝的摩尔用量为环己酮摩尔数的1.5%,回流反应6 h,己二酸收率63.7%。 比相同反应条件下用钨酸和WO3为催化剂的收率高10%~18%。     

环氧环戊烷的无溶剂合成工艺

以聚苯乙烯-二乙烯苯接枝磷钨酸季铵盐为三相相转移催化剂,以H2O2为氧化剂,KCl为助催化剂,研究了环戊烯(CPE)合成环氧环戊烷(CPEO)的无溶剂工艺。 讨论了催化剂和助催化剂用量、反应温度、反应时间、环戊烯与H2O2摩尔比对反应的影响。 确定了无溶剂环氧环戊烷合成反应的条件为(以0.056 mol H2O2计)：催化剂1.0 g、助催化剂0.025 g、反应温度40 ℃、反应时间5 h、n(CPE)∶n(H2O2)=2.1∶1.0。 CPEO的平均收率约为96%。 催化剂回收重复使用6次活性无明显降低。     

有机-无机杂化钨(钼)过氧配合物催化合成己二酸

以1,10-菲啰啉(Phen)作N,N配体制备了双核同多钨(钼)杂化过氧配合物H2M2O3(O2)4.2Phen(M:W、Mo),为己二酸的绿色合成提供了一类双功能催化剂。通过元素分析、重量法、化学滴定法、TG/DSC、IR和UV-Vis测试技术对其组成和结构进行了表征。在不使用有机溶剂和相转移催化剂的条件下,考察了它们催化30%的H2O2氧化环己烯、环己醇和环己酮合成己二酸的催化活性。实验结果表明,钨过氧配合物的催化活性较好,钼过氧配合物的催化活性差;以H2W2O3(O2)4.2Phen.H2O作催化剂,反应条件为n(底物)∶n(催化剂)∶n(H2O2)=100∶1.2∶440,反应温度为90℃,反应12 h,从环己烯、环己醇和环己酮到己二酸的收率分别为89.9%、53.5%和64.8%。     

La_2P_2W_(18)O_(62)·nH_2O/MWCNTs催化剂的制备、表征及催化1,4-丁二醇液相脱水环化合成四氢呋喃

以多壁碳纳米管(MWCNTs)为载体,通过浸渍法制备了负载型Dawson结构磷钨酸镧催化剂(40%La2P2W18O62·n H2O/MWCNTs),并对催化剂进行FT-IR,XRD,SEM,EDS和NH3-TPD表征。以催化1,4-丁二醇液相环化脱水合成四氢呋喃(THF)反应为探针,考察催化剂的酸催化性能。通过正交实验确定了优化反应条件为:w(催化剂)=2.2%(相对1,4-丁二醇质量),反应温度为180℃,反应时间为40 min。在优化反应条件下,THF收率达97.9%,催化剂重复使用5次,THF收率仍可达92.3%。镧掺杂后的催化剂酸强度和总酸量均增加,催化活性提高。     

十聚钨酸盐催化环己醇制备环己酮工艺研究

合成新型N-甲基吗啉十聚钨酸盐[Mor1,2]4W10O32,对其进行提纯、表征和催化性能研究。催化体系是以[Mor1,2]4W10O32为催化剂,30%H2O2为氧化剂,催化氧化环己醇制备环己酮。考察催化剂用量、氧化剂用量、反应温度变化和反应时间变化对环己酮产率的影响,确定最佳反应条件为:反应温度80℃、环己醇用量5mmol、催化剂用量30μmol、氧化剂H2O2用量12.5 mmol,反应时间6小时,此时环己酮产率可达到96%。     

Copolymers of tetrafluoroethene with chlorotrifluoroethene and with bromotrifluoroethene

Tetrafluoroethene (TFE)–chlorotrifluoroethene (CTFE) and TFE–bromotrifluoroethene (BTFE) copolymers have been synthesized by solution copolymerization over the entire range of comonomer composition. Crystallinity data are reported and first- and second-order transitions have been investigated by DSC. Glass transition temperatures of TFE-CTFE copolymers vary in a nonlinear fashion in the range defined by the homopolymers conforming best to the Johnston equation; the behavior in the TFE-BTFE system is more linear. Whereas TFE-BTFE copolymers show a steep decrease of melting temperature at higher BTFE content, due to the amorphous character of the polymers, more regular behavior was found for TFE-CTFE copolymers. Enthalpies of fusion are also reported. The results are discussed in relation to copolymer composition and structure and are compared with data on tetrafluoroethene–hexafluoropropene (FEP) fluorocarbon resins.     

Enthalphy of mixing of bromobenzene with n-alkanes,with cyclohexane,and with benzene

A dynamic flow microcalorimeter of the Picker design was used to measure enthalpies of mixing at 298.15 K and atmospheric pressure of the six binary systems bromobenzene + n-hexane, + n-heptane, + n-nonane, + n-tetradecane, + cyclohexane, and + benzene. Within the homologous series of n-alkane systems, the interaction parameter, h₁₂, calculated from rigid-lattice group contribution theory, decreases weakly with increasing chain length of the alkane. This behavior is quite analogous to that observed with chloro-derivatives of benzene + n-alkane.     

Reactions of amines with a dimer of hexafluoropropene and with a perfluorovinyl sulfide prepared with hexafluoropropene

Some reactions of amines with a perfluorovinylsulfide, (CF₃)₂CFSC(CF₃)CFCF(CF₃)₂, prepared from hexafluoropropene (HFP) and sulfur [1] are compared to reactions of the same amines with the thermodynamic dimer of HFP, (CF₃)₂CCFCF₂CF₃. Many new ketenimines, eneamines, amidines, nitriles, and quinoline derivatives are reported.     

Treatment of Wool with Laccase and Dyeing with Madder

This research has explored the effect of laccase (Denilite ІІ S) on the physical properties of the wool fabric and confirms the anti-felting of wool. In the experiment, laccase was applied to a wool fabric and different characteristics including weight loss, strength, alkali solubility, felting shrinkage, water drop absorption, and dye ability with madder were studied. The surface morphology of the wool fabrics was also observed by scanning electron microscope. The results indicated that the wool fabric treated with laccase has a higher water drop absorption, lower felting shrinkage, and lower values of a ^* and b ^*. Treatment of a wool fabric with 10% or lower percentage of laccase reduced the fabric weight but increased the tensile strength. However, using higher concentration of laccase reduced fabric weight and tensile strength. The dyeing of laccase pre-treated wool fabric with madder indicated a lower lightness.     

High-temperature reactions of trichloroethylene with toluene and with methanol

Conclusions The reactions of trichloroethylene with toluene and with methanol, conducted 560–570°, leads to the formation of a mixture of the isomers R-CH=CCl₂ and cis- and trans-R-CCl=CHCl (R=CH₂C₆H₅ and CH₂OH).Translated from Izvestiya Akademii Nauk SSSR. Seriya Khimicheskaya, No. 12, pp. 2777–2778, December, 1967.We thank E. D. Lubuzh and A. V. Kessenikh for determining and interpreting the IR and NMR spectra.