Matrix and Temperature Effects on the Electronic Properties of Conjugated Molecules: An Electroabsorption Study of all-trans-Retinal
Matrix and Temperature Effects on the Electronic Properties of Conjugated Molecules: An Electroabsorption Study of all-trans-Retinal
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基质和温度对共轭分子电子特性的影响：全反式视网膜的电吸收研究
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发表时间：
2000
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通讯作者：
L. Peteanu
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作者：
S. Locknar;A. A. Chowdhury;L. Peteanu
使用斯塔克效应（电吸收）光谱学研究各种聚合物基质和有机玻璃中的全反式视网膜（ATR），我们发现我们测量的激发时极化率的平均变化（）高度依赖于所用基质的刚性。在刚性聚合物和有机玻璃基质中，测量值在20 - 50 A3范围内，使用半经验方法计算的值在60 - 85 A3范围内。相比之下，当ATR夹带在非刚性聚合物基质中时，例如高于其玻璃化转变温度的那些，或含有截留溶剂的那些，测量到高达一个数量级的。我们已经假设，大的值可能是场致取向的ATR内的聚合物基质是不完全刚性的结果。的|Δμ| ATR的范围从大约3到11 D，取决于环境的极性和刚性。此外，在电吸收光谱中还观察到明显的振动结构。
Using Stark effect (electroabsorption) spectroscopy to study all-trans-retinal (ATR) in a variety of polymer matrices and organic glasses, we have found that the average change in polarizability upon excitation ( ) that we measure is highly dependent on the rigidity of the matrix used. In rigid polymer and organic glass matrices, the measured values of are in the range of 20−50 A3 and those calculated using semiempirical methods are in the range of 60−85 A3. In contrast, 's that are up to an order of magnitude higher are measured when the ATR is entrained in nonrigid polymer matrices such as those that are above their glass-transition temperature, or those containing trapped solvent. We have postulated that large values of may be the result of field-induced orientation of ATR within polymer matrices that are not fully rigid. The |Δμ| of ATR ranges from roughly 3 to 11 D, depending on the polarity and the rigidity of the environment. In addition, vibrational structure is apparent in the electroabsorption s...