2-烷基环戊-2-烯酮的简便合成新方法

2-位取代的环戊-2-烯酮是一类重要的有机合成中间体,它们的合成方法虽然已有不少文献报道,但大都路线较长,原料难得,条件苛刻且收率较低.本文报道一个以环戊二烯为原料,仅两步反应合成2-烷基环戊-2-烯酮的简便新方法. 以聚乙二醇(PEG)作为相转移催化剂,环戊二烯在氢氧化钾作用下与卤代烷在固-液相条件下反应,可方便地得到相应的烷基取代环戊二烯,主要为1-位和2-位烷基取代异构体的混合物.通过该方法制备烷基环戊二烯较之采用钠氨于液氨中反应的通常制备方法更可取.烷基环戊二烯进一步于甲醇中经溴代及酸性水解后,即可得到2-烷基环     

Luminol-K2S2O8体系中金属离子化学发光行为的研究

报导了在自行设计的流动注射式化学发光分析仪上,对Luminal-K2S2O8体系中32种金属离子的化学发光行为的系统研究.确定了对金属离子的最优测定条件以及大多数金属离子的检出极限和线性范围.     

[(C2H5)4N]2{Fe4S4[S2CN(C2H5)2]4}的晶体和分子结构

[(C2H5)4N]2{Fe4S4[S2CN(C2H5)2]4}单晶样品在Nicolet-R3四圆衍射仪上收集X射线衍射数据. 分析结果给出其晶胞参数: a=22.125(6), b=11.313(3),c=25.053A; β=118.05(2)°; V=5534.19A^3, Z=4, 空间群Cc. 衍射数据经过Lρ因子和经验吸收效应校正. 分子中铁原子的位置从三维Patterson图上得到. 接着经过若干轮Fourier和差Fourier电子云密度合成, 发现全部其余非氢原子的坐标.氢原子位置根据理论模型计算. 结构修正最后收敛至R=0.073, Rw=0.069. 标题化合物是由[(C2H5)4N]^+和{FeS4[S2CN(C2H5)2]}^2^-组成的离子型化合物. 结构的主要特点表现在阴离子上, 而在阴离子中含有类立方烷型簇核Fe4S4. 该簇核中每个铁原子与五个硫原子配位, 其配位多面体构型均为畸变的四方锥.     

[Bu~4N]~3[Mo~2FeS~8O].(CH~2OH)~2簇合物的合成, 结构和性质研究

(NH4)2MoS~4、FeCl~3与乙二醇钠在乙二醇溶液中反应, 再与Bu~4NBr作用可得到一种M0-Fe-S簇合物[Bu~4N]~3[Mo~2FeS~8O].HOCH~2OH。其结构经X光晶体结构分析确定。并测定其红外光谱、紫外光谱、Mossbauer谱和电化学性质。该化合物可催化KBH~4转化乙炔还原为乙烯的反应。     

β-二酮二氰乙基化合物的酮解反应

甲基酮与丙烯腈反应可以得到一氰乙基、二氰乙基或多氰乙基化产物。据文献报道,丙酮与丙烯腈反应可以得到少量的4-乙酰基庚二腈,产率约为3.7％,其他4-酰基庚二腈的合成方法还未见报道。我们发现由β-二酮的氰乙基化反应得到的β-二酮二氰乙基化产物1a～c,在碳酸钠水溶液中酮解可以得到4-酰基庚二腈2a～c,产率为59～82％。如果1a～c在氢氧化钾水溶液中水解,则得4-酰基庚二酸3a～c。2a～c与2,4-二硝基苯肼反应得到了相应的苯腙4a～c,2a～c经KOH水解亦得3a～c。     

三核铁配合物[Fe~3(μ~3-O)(μ-O~2CH)~6(H~2O)~2(O~2CH)].2H~2O的合成、结构和性能的研究

本文合成了含μ~3-O的三核铁甲酸配合物[Fe~3(μ~3-O)(μ-O~2CH)~6(H~2O)~2(O~2CH)].2H~2O进行了元素分析、红外与Raman光谱、核磁与顺磁共振波谱分析和磁化率测定, 并作了配合物的X射线单晶结构分析。比较了同系物的结构, 且讨论了波谱及其它性能的研究结果。     

Schiff碱配合物的研究II: 一些Fe(III)配合物的磁性质与电化学行为

Fe(III)schiff碱配合物的磁性质和电化学还原性是该类配合物的基本特性, 本文研究三种配合物, 单核高自旋配合物, 单核低自旋配合物以及氧桥双核配合物的核磁共振性质电化学还原性。     

铁铂硫原子簇化合物的合成与结构研究 V: [MoFe3S4]类立方烷簇合物的转化反应和[Et4N]3[Mo2Fe6S8(SC6H4CH3-m)3Cl6]的晶体结构

具[MoFe2S4]类立方烷结构单元的双类立方烷化合物[Et4N]4[Mo2Fe7S8(SR)12](1a,R=Ph; 1b, R=tolyl-m)或单类立方烷化合物[MoFe3S4(dteR2)5](2a, R=Me; 2b, R=Et)与酰氯在乙腈中反应, 分别得到不含Fe桥的双类立方烷化合物(Et4N)3[Mo2Fe6S8(SR)3Cl6](3a, R=Ph; 3b, R=toly-m)与[MoFe3S4]骨架支解后的Fe(dteR2)2Cl(4a, R=Me; 4b, R=Et)。说明在相同反应条件下, [MoFe3S4]单元在1中比在2中稳定, 本文首次将1型与3型结构通过一步化学反应连系起来。3型化合物的产生得到X射线衍射测定及^1H NMR谱的证实。本文报道3b的单晶结构及3的^!H NMR数据, 3b属六方晶系, P63/m, a=1.6827(3), c=1.5951(16)nm; V=3.91158nm^3; Dc=1.491g/cm^3;Z=2; F(000)=1780; 偏离因子R=0.048, 化合物2与酰氯反应产生4, 由红外及紫外可见光谱证实。     

Effect of Particle Size on the Thermal Stability and Flammability of Mg(OH)2/EVA Nanocomposites

The effect of the Mg(OH)₂ particle size on the thermal degradation and flammability of a model nanocomposite is presented. In order to investigate the effect of particle size on the flammability and thermal stability of materials intended for cable coatings, the ethylene–vinyl acetate copolymer (EVA) was filled with two types of magnesium hydroxide (Mg(OH)₂) with the average particle size 20 nm and 2000 nm. The thermogravimetric experiments performed under nitrogen and air atmosphere did not reveal any substantial effect of particle size on the mechanisms and kinetics of Mg(OH)₂ decomposition. Both types of Mg(OH)₂, at temperatures above 350°C, decomposed endothermally to MgO and H₂O. At the same filler volume fraction, composites with the larger Mg(OH)₂ particles exhibited greater value of the limiting oxygen index (LOI) compared to Mg(OH)₂ nanocomposites. It is proposed that the reduction of Mg(OH)₂ particle size below 200 nm results in the catalytic effect of Mg²⁺ to become more prominent compared to coarser particles. In the case of nano-sized Mg(OH)₂, a large portion of polymer matrix is in direct contact with filler surface due to the high specific surface area of the filler used. Large filler–matrix contact area most probably resulted in the surface-induced catalytic effects of the Mg²⁺ ion on degradation of polyolefins, already described in the literature, accelerating thermal degradation of EVA matrix. This process acts against the flame retarding effect of the Mg(OH)₂ thermal decomposition. Furthermore, larger filler surface of nano-filler led to the indispensable change of the deformation response of EVA compared to the micro-filled composite.     

Evolution of reactive unsaturated interfacial modifiers for polyolefin based composites

The development of a novel reactive unsaturated interfacial modifier for filled (magnesium hydroxide, aluminium hydroxide and calcium carbonate) polyolefins is reviewed. Initial work explored maleimide functional candidate molecules including 1,3-phenylene dimaleimide (1,3-PDM) and a range of linear alkyl dimaleimides. Most of the dimaleimides were very effective interfacial modifiers in polypropylene and poly(ethylene-co-vinylacetate) (18% w/w vinylacetate) based composites. However, the dimaleimides caused the composites to have a distinct pink/brown colouration apart from when the maleimide groups were spaced by a C12 alkyl chain. The problem with colour and high effective dosage prompted a switch to unsaturated carboxylic acid based systems. The performance of a range of unsaturated carboxylic acids and the hexafunctional monomer trimethylolpropane triacrylate are reviewed, together with a novel oligomeric unsaturated carboxylic acid (OUCA) based system developed by the Noveon Division of Lubrizol Limited. The data obtained from this series of interfacial modifiers, and adsorption studies on 1,3-PDM and OUCA, afforded some insight into the competing factors (such as the strength of adsorption versus ability to form a polymerised interfacial layer and the ability to react with matrix chains) that significantly affect the coupling performance of interfacial modifiers.