烃在四种典型活性炭中吸附状态随温度变化的~1H NMR和~2H NMR的研究

本文观察了吸附在四种孔结构活性炭中苯,环已烷和正已烷的~1H NMR和笊代苯的~2H NMR谱线在297～195 κ温度范围内的变化。在室温下被吸附的上述各种化合物的~1H NMR及~2H NMR谱均为一条线宽不同的单峰,且随温度下降而增宽。在~2H NMR谱中发现,当以对数表示的谱线半高宽和绝对温度倒数的直线关系上出现拐点时,同时可观察到固体粉末谱线。除2~#活性炭外,最初出现固体粉末谱的温度大致相同。这暗示粉末谱是毛细管中三维类液体固化的结果。文内就所观察到的现象进行了初步讨论。

~1H AND ~2H NMR STUDIES OF THE ADSORPTION STATE OF HYDROCARBONS ON FOUR TYPICAL CHARCOALS AT VARIOUS TEMPERATURES

1H NMR spectra of benzene, cyclohexane and n -hexane and 2H NMR spectra of benzene -d6 absorbed on four charcoals with different pore structures were measured at various temperatures in the range from 297 to 195 K. At room temperature 1H NMR and 2H NMR spectra of each of the above mentioned compounds were singlets with different line widths which increased with decreasing temperature. The In vs. reciprocal absolute temperature plots showed linear relationship with intersection. For C6D6 systems solid powder patterns were observed at temperatures where intersection occurred. Except for charcoal 2# solid powder patterns appeared at almost identical temperatures for charcoal 3#, 4# and 5#. The appearence of solid powder patterns suggests that the absorbed species in the 3D liquid state turned to 3D solid.