Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States.
J Phys Chem A. 2023 Jul 13;127(27):5704-5712. doi: 10.1021/acs.jpca.3c02734. Epub 2023 Jun 27.
Platinum cation complexes with multiple acetylene molecules are studied with mass spectrometry and infrared laser spectroscopy. Complexes of the form Pt(CH) are produced in a molecular beam by laser vaporization, analyzed with a time-of-flight mass spectrometer, and selected by mass for studies of their vibrational spectroscopy. Photodissociation action spectra in the C-H stretching region are compared to the spectra predicted for different structural isomers using density functional theory. The comparison between experiment and theory demonstrates that platinum forms cation-π complexes with up to three acetylene molecules, producing an unanticipated asymmetric structure for the three-ligand complex. Additional acetylenes form solvation structures around this three-ligand core. Reacted structures that couple acetylene molecules (e.g., to form benzene) are found by theory to be energetically favorable, but their formation is inhibited under the conditions of these experiments by large activation barriers.
铂阳离子与多个乙炔分子的配合物通过质谱和红外激光光谱进行研究。Pt(CH) 形式的配合物通过激光蒸发在分子束中产生，用飞行时间质谱仪进行分析，并通过质量选择进行振动光谱研究。在 C-H 伸缩区域的光解离作用光谱与使用密度泛函理论预测的不同结构异构体的光谱进行比较。实验与理论的比较表明，铂与多达三个乙炔分子形成阳离子-π 配合物，为三配体配合物产生了意想不到的不对称结构。额外的乙炔分子在这个三配体核心周围形成溶剂化结构。理论发现，将乙炔分子偶联（例如，形成苯）的反应结构在能量上是有利的，但在这些实验条件下，由于较大的活化能垒，其形成受到抑制。
