Communication: The highest frequency hydrogen bond vibration and an experimental value for the dissociation energy of formic acid dimer
Communication: The highest frequency hydrogen bond vibration and an experimental value for the dissociation energy of formic acid dimer
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DOI：
10.1063/1.4704827
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发表时间：
2012-04-21
影响因子：
4.4
通讯作者：
Suhm, M. A.
中科院分区：
文献类型：
--
作者：
Kollipost, F.;Larsen, R. Wugt;Suhm, M. A.
甲酸二聚体的最高频率氢键基频v（24）（B-u）位于264 cm（-1）处。本文给出了（HCOOH）（2）的这种面内弯曲模及其对称D同位素体（同位素异构体）在超声狭缝射流膨胀中的谱带中心的FTIR光谱。与早期在室温下的研究相比，热激发对能带最大值的影响很大。再加上三个B-U组合状态，涉及氢键的基本原理和拉曼活性模式的最新进展，这带来了达到一个准确的统计热力学处理的二聚过程，直到室温。我们获得D-0 = 59.5（5）kJ/mol作为0 K下二聚体解离能的最佳实验估计值。进一步的改进必须等待更一致的室温平衡常数的测定。(C)2012年美国物理学会。[http：//dx.doi.org/10.1063/1.4704827]
The highest frequency hydrogen bond fundamental of formic acid dimer, v(24) (B-u), is experimentally located at 264 cm(-1). FTIR spectra of this in-plane bending mode of (HCOOH)(2) and band centers of its symmetric D isotopologues (isotopomers) recorded in a supersonic slit jet expansion are presented. Comparison to earlier studies at room temperature reveals the large influence of thermal excitation on the band maximum. Together with three B-u combination states involving hydrogen bond fundamentals and with recent progress for the Raman-active modes, this brings into reach an accurate statistical thermodynamics treatment of the dimerization process up to room temperature. We obtain D-0 = 59.5(5) kJ/mol as the best experimental estimate for the dimer dissociation energy at 0 K. Further improvements have to wait for a more consistent determination of the room temperature equilibrium constant. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4704827]