超临界流体色谱中溶质的保留行为

超临界流体色谱中热力学参数最佳化和动力学最佳化同等重要。溶质的保留行为和物质对的分离受柱固定相和流动相各种参数的影响。在本研究中,使用纯CO_2作为流动相,饱和烃、芳烃、以及它们的硝基取代物作为溶质,对上述影响进行了系统地考察。结果发现影响物质对分离的(以分离系数,α,表示)最主要因素是流体的密度。而温度的影响并不明显。柱固定相的性质也有一定程度的影响。在柱固定相相同的情况下,改变操作参数,溶质峰的洗馏顺序可能出现倒置。表明在超临界流体色谱中流动相溶解能力的重要作用。实验结果为了解和优化超临界流体色谱热力学参数提供了依据。     

ELECTRON-TRANSFER REACTIONS OF CROSSLINKED POLY(1-PYRIDINIOMETHYL)STYRENE CHLORIDE 2. REDUCTION OF NITRO-COMPOUNDS

Continuing the study of electron transfer reactions of polypyridiniomethylstyrene chloride (PSPyCl), the reduction of nitro-compounds by the PSPyCl-Zn system was investigated. In general azoxy compounds were obtained as chief intermediate product of reduction. Reduction of nitrobenzo-15-crown-5 and its homologues give a new class of bis-crown ether compounds——azoxy-bisbenzocrown ethers. Azoxybisbenzocrown ethers undergo photoinduced trans-cis isomerization, which is reversible on irradiation with UV and on storage in darkness, similar to the case of azobiscrown ethers. Investigation of solvent extraction of various cations by azobiscrown ether isomers shows that cis-azoxybisbenzo-15-crown-5 exhibit good selectivity toward Nd~(3 ) from other rare earth cations.     

氧化偶氮双苯并-15-冠-5的合成及其性质

合成了一种新的双冠醚,氧化偶氮双苯并15-冠-5。初步探讨了它的光异构现象及其对稀土和碱金属离子的萃取能力。