PHOTODISSOCIATION SPECTROSCOPY OF THE NEGATIVE-ION DIMER OF TOLUQUINONE
PHOTODISSOCIATION SPECTROSCOPY OF THE NEGATIVE-ION DIMER OF TOLUQUINONE
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DOI：
10.1021/ja00259a001
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发表时间：
1987-12-09
影响因子：
15
通讯作者：
BRAUMAN, JI
中科院分区：
文献类型：
--
作者：
COMITA, PB;BRAUMAN, JI
用离子回旋共振谱仪测定了负离子二聚体甲苯醌的光解离谱。已确定在1.9 eV的电荷共振跃迁，其中显示在高分辨率的个人电子振动跃迁。由数据确定了二聚体的键离解能和电子亲合能。电荷共振跃迁被拟合到单振子理论模型，并提取了电子结构的细节。对数据的拟合表明，自由基离子二聚体中的奇电子是强定域的。由于对这些物种的热力学和光谱信息相对较少，分子离子簇组分之间的键合性质尚未得到很好的定义。分子离子二聚体是最简单的团簇，可以作为研究分子离子与其相应的中性分子之间成键的出发点。我们首次获得了醌负离子二聚体的气相光解离光谱数据。这些数据包含的能量信息，hasbeen理论分析，并可能有助于阐明一个物种的电子结构，它可以被描述为一个自由基离子络合到一个中性分子在本地化的限制或一个物种之间的强电子耦合的亚基在基态的离域限制。
The photodissociation spectrum of the negative ion dimer of toluquinone has been determined in an ion cyclotron resonance spectrometer. A charge resonance transition at 1.9 eV, which displays individual vibronic transitions at high resolution, has been identified. The bond dissociation energyand electron affinity of the dimer were determined from the data. The charge resonance transition was fit to a single-oscillator theoretical model and details of the electronic structure were extracted. The fit to thedata indicates that the odd electron in the radical ion dimer is strongly localized.The nature of the bonding between the constituents of molecular ionic clusters has not yet been well-defined, dueto therelatively little thermodynamic and spectroscopic information available on these species. Molecular ion dimers, the simplest of the clusters, can be taken as a starting point for investigations into the bonding between molecular ions and their corresponding neutrals. We have obtained spectroscopic data for the first time on a negative ion dimer of a quinone via gas-phase photodissociation spectroscopy. The data contain energetic information that hasbeen theoretically analyzed and may help to elucidate the electronic structure of a species which can either be described as a radical ion complexed to a neutral molecule in the localized limit or a species with strong electronic coupling between the subunits in the ground state in the delocalized limit.