2-Acetamidoacrylic acid or methyl 2-acetamidoacrylate is reacted with solution of sodium of methylselenol to give N-acetyl-Se-methylselenocysteine.The L(and D)-Se-methylselenocysteine have been prepared in high optica...2-Acetamidoacrylic acid or methyl 2-acetamidoacrylate is reacted with solution of sodium of methylselenol to give N-acetyl-Se-methylselenocysteine.The L(and D)-Se-methylselenocysteine have been prepared in high optical purity by treating N-acetyl-Se-methylselenocysteine in water using acylase I from porcine kidney as a catalyst.The influencing factors on the resolution reaction are discussed by orthogonal experiment,including pH value,reaction temperature,concentration of Co2+ and amount of acylase I.Under the optimizing resolution conditions,L(and D)-Se-methylselenocysteine are obtained with>96 % optical purity in about 40% yield.展开更多
文摘2-Acetamidoacrylic acid or methyl 2-acetamidoacrylate is reacted with solution of sodium of methylselenol to give N-acetyl-Se-methylselenocysteine.The L(and D)-Se-methylselenocysteine have been prepared in high optical purity by treating N-acetyl-Se-methylselenocysteine in water using acylase I from porcine kidney as a catalyst.The influencing factors on the resolution reaction are discussed by orthogonal experiment,including pH value,reaction temperature,concentration of Co2+ and amount of acylase I.Under the optimizing resolution conditions,L(and D)-Se-methylselenocysteine are obtained with>96 % optical purity in about 40% yield.
基金supported by the National Natural Science Foundation of China (21825103)Hubei Provincial Natural Science Foundation of China (2019CFA002)the Fundamental Research Funds for the Central Universities (2019kfy XMBZ018)。
文摘二维(2D)三元材料近年来如雨后春笋般兴起,由于其物理性质能够通过调整化学计量比来实现自由设计而被认为在光电子学中具有重要的应用前景.然而,具有良好化学计量比的高质量二维三元材料的可控制备仍然面临挑战,严重阻碍了它们进一步的发展和在未来器件中的应用.本文中,我们通过一种常压固体源热蒸发法在云母衬底上制备了厚度薄至4 nm,横向尺寸约为60μm的三元Bi_(2)Te_(2)Se(BTS)薄片.通过变温拉曼光谱和导电性测量研究了二维BTS的声子振动和电传输特性.进一步地,基于二维BTS的光电探测器表现出优异的光电响应特性,其光开关比在365 nm光照下约为1300,光谱响应范围宽至365–980 nm,同时其响应速度快至2μs.此外,栅极电压能够有效调控BTS的电输运和光电性能,从而将980 nm下的红外响应度和光开关比提高至2.74 A W^(-1)和2266.我们的工作介绍了一种有效获得二维BTS薄片的方法,并展示了其在光电领域良好的应用前景.
