In this work, the structural fluctuations and vibrational energy transfer dynamics in a supramolecular homodimer model, which is composed of 2-(9-anthracene)ureido-6-(1-undecyl)-4[1H]-pyrimidinone (UPAn) with quadruple intermolecular and single intramolecular hydrogen bonds (HBs), have been examined using ultrafast two-dimensional infrared (2D IR) and steady-state IR spectroscopies. A less structurally fluctuating intermolecular HB is found between the pyrimidinone C═O and ureido N-H groups. However, a larger structurally fluctuating intramolecular HB is suggested by the equilibrium and dynamical line-shape measurements of the ureido C═O stretch. Further, dynamical time-dependent 2D IR diagonal and off-diagonal signals show that intra- and intermolecular vibrational energy transfer processes occur on the picosecond timescale, where the latter is more efficient due to intermolecular hydrogen bonding interaction and through-space interaction.

中文翻译：

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通过二维红外光谱通过超分子二聚体中的共价键以及分子内和分子间氢键实现超快振动能量转移。

在这项工作中，由2-（9-蒽）ureido-6-（1-十一烷基）-4 [1H]-嘧啶酮（UPAn）四倍组成的超分子同二聚体模型中的结构涨落和振动能量传递动力学。分子间和单个分子内氢键（HBs）已使用超快二维红外光谱（2D IR）和稳态红外光谱学进行了研究。在嘧啶酮C ＝ O和脲基NH基团之间发现了结构上波动较小的分子间HB。然而，通过尿素C ＝ O拉伸的平衡和动态线形测量表明，结构上波动较大的分子内HB。此外，与时间相关的动态2D IR对角线和非对角线信号表明，在皮秒级的时间范围内会发生分子内和分子间的振动能量转移过程，