Entrapped Energy in Chiral Solutions: Quantification and Information Capacity

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• 作者：Meir Shinitzky ; Ayelet Shvalb ; Avshalom C. Elitzur ; Yitzhak Mastai
• 刊名：Journal of Physical Chemistry B
• 出版年：2007
• 出版时间：September 20, 2007
• 年：2007
• 卷：111
• 期：37
• 页码：11004 - 11008
• 全文大小：92K
• 年卷期：v.111,no.37(September 20, 2007)
• ISSN：1520-5207

文摘

A homogeneous solution of a chiral substance stores a residual chemical potential, related to its overallanisotropy. Therefore, by mixing solutions of opposite enantiomers, heat release may take place, correspondingto the mutual anisotropy annulment. In the following study we present proofs for this fundamental, yetunexplored, prediction by measuring the heat released upon mixing of aqueous solutions of D-proline withL-proline, as well as D-alanine with L-alanine, using isothermal titration calorimetry. Heat release in the rangeof 0.6-6 cal/mol was detected in these intermolecular racemizations at 30 C. Its magnitude varied linearlywith the apparent optical rotation, which complied with the possibility that the hydration envelope coatingthe chiral molecule is of a long-range condensed and asymmetrical configuration that can expand by integrationwith adjacent hydration envelopes. The ordered water in such hydration layers constitutes regions of "negativeentropy", a basic medium for information storage. On the basis of our findings, a fundamental expressionwhich combines entropy, information capacity, and thermal energy is proposed.