以三(三甲基硅基)肼锂和对甲苯磺酰叠氮为起始原料,合成了高活性的1,2‐二(三甲基硅基)二氮烯(BSD),进一步利用其二聚反应,合成了1,1,4,4‐四(三甲基硅基)四氮烯(TST),总收率约5.0%,通过核磁共振谱、红外光谱、元素分析和紫外‐可见吸...以三(三甲基硅基)肼锂和对甲苯磺酰叠氮为起始原料,合成了高活性的1,2‐二(三甲基硅基)二氮烯(BSD),进一步利用其二聚反应,合成了1,1,4,4‐四(三甲基硅基)四氮烯(TST),总收率约5.0%,通过核磁共振谱、红外光谱、元素分析和紫外‐可见吸收光谱对BSD和TST的结构进行了表征。通过量子化学计算方法研究了BSD二聚反应的机理。结果表明,发现其先异构化为1,1‐二(三甲基硅基)二氮烯中间体,然后两个中间体相互作用形成TST,两个过程分别需要高达103.0 k J·mol^(-1)和114.3 k J·mol^(-1)的活化能,该理论结果与高温条件有利于BSD转化为TST的实验现象一致。展开更多
To improve oxygen-enriching properties of cellulose derivative membranes, trimethylsilyl methylcellulose (TMS-MC) with degree of substitution (DS) of 1.12 was synthesized by using methylcellulose with DS of 1.80 as ra...To improve oxygen-enriching properties of cellulose derivative membranes, trimethylsilyl methylcellulose (TMS-MC) with degree of substitution (DS) of 1.12 was synthesized by using methylcellulose with DS of 1.80 as raw material and hexamethyldisilazane as reactant in a homogeneous reactive system.The chemical structures of TMS-MC were characterized with FT-IR and 1H NMR.The product samples were fairly soluble in ordinary organic solvents such as tetrahydrofuran, chloroform, xylene, toluene, and so on.The gas separation membranes were prepared by casting a xylene solution of TMS-MC on a sheet of PET.It was found that the oxygen permeation properties of the TMS-MC membrane were improved and an obvious increase in separation factor was obtained especially.Comparing with methylcellulose, for example, the permeability coefficient and separation factor of the TMS-MC membrane increased from 2.5 Barrer and 2.41 to 23.85 Barrer and 5.42 at 20℃, respectively.展开更多
Polyphenylene dendrimers 11,12 and 13 containing terminal trimethylsilyl groups have been synthesized by phosphine-free palladium chloride catalyzed Suzuki couplings of 1,3,5-tris(3′,5′-dibromophenyl)benzene 9 with ...Polyphenylene dendrimers 11,12 and 13 containing terminal trimethylsilyl groups have been synthesized by phosphine-free palladium chloride catalyzed Suzuki couplings of 1,3,5-tris(3′,5′-dibromophenyl)benzene 9 with aryl boronic acids 5 and 6.These macromolecules were characterized by Fourier transform infrared (FTIR),nuclear magnetic resonance (NMR) and matrix assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectra.Gel permeation chromatograph (GPC) indicated that the hydrodynamic radium of 12,with trimethylsiliyl (—TMS) groups substituted at para-positions on its terminal benzene rings,was larger than that of 13,with trimethylsiliyl groups substituted at meta-positions on its terminal benzene rings.X-ray powder diffraction patterns showed that dendrimer 12 was of a certain amount of crystallinity and dendrimer 13 was amorphous.展开更多
文摘以三(三甲基硅基)肼锂和对甲苯磺酰叠氮为起始原料,合成了高活性的1,2‐二(三甲基硅基)二氮烯(BSD),进一步利用其二聚反应,合成了1,1,4,4‐四(三甲基硅基)四氮烯(TST),总收率约5.0%,通过核磁共振谱、红外光谱、元素分析和紫外‐可见吸收光谱对BSD和TST的结构进行了表征。通过量子化学计算方法研究了BSD二聚反应的机理。结果表明,发现其先异构化为1,1‐二(三甲基硅基)二氮烯中间体,然后两个中间体相互作用形成TST,两个过程分别需要高达103.0 k J·mol^(-1)和114.3 k J·mol^(-1)的活化能,该理论结果与高温条件有利于BSD转化为TST的实验现象一致。
文摘To improve oxygen-enriching properties of cellulose derivative membranes, trimethylsilyl methylcellulose (TMS-MC) with degree of substitution (DS) of 1.12 was synthesized by using methylcellulose with DS of 1.80 as raw material and hexamethyldisilazane as reactant in a homogeneous reactive system.The chemical structures of TMS-MC were characterized with FT-IR and 1H NMR.The product samples were fairly soluble in ordinary organic solvents such as tetrahydrofuran, chloroform, xylene, toluene, and so on.The gas separation membranes were prepared by casting a xylene solution of TMS-MC on a sheet of PET.It was found that the oxygen permeation properties of the TMS-MC membrane were improved and an obvious increase in separation factor was obtained especially.Comparing with methylcellulose, for example, the permeability coefficient and separation factor of the TMS-MC membrane increased from 2.5 Barrer and 2.41 to 23.85 Barrer and 5.42 at 20℃, respectively.
文摘Polyphenylene dendrimers 11,12 and 13 containing terminal trimethylsilyl groups have been synthesized by phosphine-free palladium chloride catalyzed Suzuki couplings of 1,3,5-tris(3′,5′-dibromophenyl)benzene 9 with aryl boronic acids 5 and 6.These macromolecules were characterized by Fourier transform infrared (FTIR),nuclear magnetic resonance (NMR) and matrix assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectra.Gel permeation chromatograph (GPC) indicated that the hydrodynamic radium of 12,with trimethylsiliyl (—TMS) groups substituted at para-positions on its terminal benzene rings,was larger than that of 13,with trimethylsiliyl groups substituted at meta-positions on its terminal benzene rings.X-ray powder diffraction patterns showed that dendrimer 12 was of a certain amount of crystallinity and dendrimer 13 was amorphous.
