Ultrafast Energy Migration Pathways in Self-Assembled Phospholipids Interacting with Confined Water

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• 作者：Nancy E. Levinger ; Rene Costard ; Erik T. J. Nibbering ; Thomas Elsaesser
• 刊名：Journal of Physical Chemistry A
• 出版年：2011
• 出版时间：November 3, 2011
• 年：2011
• 卷：115
• 期：43
• 页码：11952-11959
• 全文大小：1005K
• 年卷期：v.115,no.43(November 3, 2011)
• ISSN：1520-5215

文摘

Phospholipids self-assembled into reverse micelles in benzene are introduced as a new model system to study elementary processes relevant for energy transport in hydrated biological membranes. Femtosecond vibrational spectroscopy gives insight into the dynamics of the antisymmetric phosphate stretching vibration 谓_AS(PO₂)^{鈭?/sup>, a sensitive probe of local phosphate鈥搘ater interactions and energy transport. The decay of the 谓_AS(PO₂)鈭?/sup> mode with a 300-fs lifetime transfers excess energy to a subgroup of phospholipid low-frequency modes, followed by redistribution among phospholipid vibrations within a few picoseconds. The latter relaxation is accelerated by adding a confined water pool, an efficient heat sink in which the excess energy induces weakening or breaking of water鈥搘ater and water鈥損hospholipid hydrogen bonds. In parallel to vibrational relaxation, resonant energy transfer between 谓_AS(PO₂)鈭?/sup> oscillators delocalizes the initial excitation.}