Analysis of electron-molecular vibration interactions in π-electron conjugated radical ion species

(1)利用透射探针结合中红外光纤束，对氘化四氢呋喃中萘的阴离子自由基和氘化二氯甲烷中4,4′-二甲基联苯的阳离子自由基进行了高质量的红外光谱观测。透射探头可在真空条件下插入带o形环的玻璃管电池中。在真空系统中单独制备的有机自由基离子被转移到细胞中进行红外吸收测量。观测到的红外光谱与基于密度泛函理论的计算光谱吻合较好。(2)通过密度泛函理论计算得到了2,5“”-二甲基五硫代噻吩和[2.2]五硫代噻吩的中性物质和自由基阳离子的分子结构、红外吸收光谱和拉曼光谱。计算了[2.2]蒽醌醌的强红外吸收特性。这些强红外吸收的振动模式在两个五倍埃塞俄比亚烯部分是相异的。2,5 ' ' -二甲基五硫代埃塞俄比亚烯自由基阳离子对应的振动模式具有较弱的红外吸收强度。

(1) By using a transmission probe combined with bundles of mid-infrared optical fibers, high-quality infrared spectra have been observed for the radical anion of naphthalene in deuterated tetrahydrofuran and the radical cation of 4,4'-dimethylbiphenyl in deuterated dichloromethane. The transmission probe can be inserted into a glass-tube cell with O-rings under vacuum. Organic radical ions prepared separately in a vacuum system are transferred into the cell for infrared absorption measurements. Observed infrared spectra are in good agreement with calculated spectra based on density functional theory..(2) The molecular structures and infrared absorption and Raman spectra of the neutral species and radical cation of 2,5""-dimethylquinquethiophene and the neutral species and dication of [2.2]quinquethiophenophane were obtained by density functional theory calculations. Strong infrared absorptions characteristic of the dication of [2.2]quinquethiophenophane were calculated. The vibrational modes of these strong infrared absorptions are out-of-phase in the two quinquethiophene parts. The corresponding vibrational modes of the radical cation of 2,5""-dimethyIquinquethiophene have weak infrared absorption intensities.