Charge Transfer Exciton in Halogen-Bridged Mixed-Valent Pt and Pd Complexes: Analysis Based on the Peierls-Hubbard Model
Charge Transfer Exciton in Halogen-Bridged Mixed-Valent Pt and Pd Complexes: Analysis Based on the Peierls-Hubbard Model
复制标题
卤素桥混合价 Pt 和 Pd 配合物中的电荷转移激子：基于 Peierls-Hubbard 模型的分析
DOI：
10.1143/jpsj.54.3143
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发表时间：
1985
影响因子：
1.7
通讯作者：
T. Koda
中科院分区：
文献类型：
--
作者：
Y. Wada;T. Mitani;M. Yamashita;T. Koda
测量了[MA2][MX2A2](ClO4)4(M=铂、钯、X=氯、溴、碘和A=乙二胺、环己二胺)单晶的偏振反射和发光。详细研究了混合价金属离子间电荷转移激子跃迁在可见光或红外能区产生的强吸收带。CT激发能对物种M和X的依赖关系与Peierls-Hubbard模型的预测是一致的，该模型考虑了金属间电子关联的影响。观察到通过取代较重的卤素离子可以增强CT激子的振子强度。这种增强是由卤素连接的超转移机制解释的。振子强度的异常大可以用三聚体CT模型定性地解释。
Polarized reflection and luminescence have been measured for the single crystals of [MA 2 ][MX 2 A 2 ](ClO 4 ) 4 (M=Pt, Pd, X=Cl, Br, I and A=ethylenediamine, cyclohexanediamine). The strong absorption bands due to the charge-transfer (CT) exciton transitions between the mixed-valent metal ions have been investigated in detail in the visible or infrared energy regions. The dependence of the CT excitation energies on the species M and X is shown to be consistent with the prediction by the Peierls-Hubbard model which incorporates the effect of the electron-electron correlation on inter-metal sites. The oscillator strength of the CT excitons are observed to be enhanced by substituting heavier halogen ions. This enhancement is interpreted by a halogen-linked super-transfer mechanism. The unusually large values of the oscillator strength can be qualitatively explained in terms of the trimer CT model.