検索対象:     
報告書番号:
※ 半角英数字
 年 ~ 
 年

Temperature and density effects on the absorption maximum of solvated electrons in sub- and super-critical methanol

亜臨界・超臨界メタノール中での溶媒和電子の光吸収ピークの温度及び密度依存性

Yan, Y.*; Lin, M.; 勝村 庸介*; 室屋 裕佐*; 山下 真一; 端 邦樹 ; Meesungnoen, J.*; Jay-Gerin, J.-P.*

Yan, Y.*; Lin, M.; Katsumura, Yosuke*; Muroya, Yusa*; Yamashita, Shinichi; Hata, Kuniki; Meesungnoen, J.*; Jay-Gerin, J.-P.*

パルスラジオリシス法及びレーザーフォトリシス法を用いて、亜臨界及び超臨界状態(220-270$$^{circ}$$C)におけるメタノール中溶媒和電子の光吸収スペクトル変化を計測した。溶媒和電子の吸収ピーク($$E$$$$_{rm Amax}$$)は溶媒の密度に依存し、0.45-0.59g/cm$$^{3}$$の範囲で増加させると高エネルギー側へシフトした。水に関する過去の実験結果と同じく、$$E$$$$_{rm Amax}$$は圧力一定下においては臨界温度を超えてもなお単調減少するが、逆に密度一定下においては、臨界温度に極小点を持つことがわかった。このようなスペクトルの振る舞いを、メタノールの温度・圧力変化に伴う物性値や分子構造の変化により議論した。

The optical absorption spectra of the solvated electron (e$$_{rm sol}^-$$) in sub- and super-critical methanol are measured by both electron pulse radiolysis and laser photolysis techniques, at temperatures in the range 220-270 $$^{circ}$$C. Over the density range studied ($$sim$$0.45-0.59 g/cm$$^{3}$$), the position of the absorption maximum ($$E$$$$_{rm Amax}$$) of e$$_{rm sol}^-$$ is found to shift only slightly to the red with decreasing density. In agreement with our previous work in water, at a fixed pressure, $$E$$$$_{rm Amax}$$ decreases monotonically with increasing temperature in passing through the phase transition at $$T$$$$_{rm c}$$ (239.5 $$^{circ}$$C). By contrast, at a fixed density, $$E$$$$_{rm Amax}$$ exhibits a minimum as the solvent passes above the critical point into the supercritical state. These behaviors are discussed in terms of microscopic arguments based on the changes that occur in the methanol properties and methanol structure in the sub- and supercritical regimes.

Access

:

- Accesses

InCites™

:

パーセンタイル:7.14

分野:Chemistry, Multidisciplinary

Altmetrics

:

[CLARIVATE ANALYTICS], [WEB OF SCIENCE], [HIGHLY CITED PAPER & CUP LOGO] and [HOT PAPER & FIRE LOGO] are trademarks of Clarivate Analytics, and/or its affiliated company or companies, and used herein by permission and/or license.