FILLING OF SOLVENT SHELLS ABOUT IONS .1. THERMOCHEMICAL CRITERIA AND THE EFFECTS OF ISOMERIC CLUSTERS
FILLING OF SOLVENT SHELLS ABOUT IONS .1. THERMOCHEMICAL CRITERIA AND THE EFFECTS OF ISOMERIC CLUSTERS
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DOI：
10.1021/j100283a006
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发表时间：
1986-12-04
影响因子：
--
通讯作者：
SPELLER, CV
中科院分区：
文献类型：
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作者：
MEOTNER, M;SPELLER, CV
结论固体载体对颜料分子光谱性质的影响主要通过三种相互作用来确定：电子-声子耦合、特异性溶剂化和非特异性溶剂化。我们用窄带记录的激发光谱中的相对线背景强度来表征第一个。在非晶态、玻璃体基质中获得了最好的锐线光谱。白雪，晶体样品产生较差的振动分辨率，至少在Chi系列的情况下。颜料与基质分子的分子复合物的性质取决于溶剂的特定性质、亲核性和亲电性。PChl和Chi a中心Mg原子的外配位数（1或2）可以通过高分辨激发光谱确定。非特异性相互作用对德拜-沃勒因子和溶剂化物类型的影响可以忽略不计。然而，非均匀位点分布函数的宽度和最大值（以及吸收和非选择性激发的荧光最大值）（通过色散相互作用和斯塔克位移）与色素分子最近环境中的局部极化率和电荷密度有关。
ConclusionsThe influence of the solid host on the spectroscopic properties of the pigment molecule is determined, generally, by three types of interactions: the electron-phonon coupling, the specific sol-vation, and the nonspecific solvation. We have characterized the first one by relative line-to-background intensity in the narrow-band recorded excitation spectra. The best sharp-line spectra could be obtained in amorphous, vitreous matrices. Snowy, crystalline samples yield poorer vibronic resolution, at least in the case of the Chi a series.The nature of the molecular complexes of the pigment with matrix molecules depends on the specific properties of the solvent, its nucleophilicity, and its electrophilicity. The extracoordination number (1 or 2) of the PChl and Chi a central Mg atom could be ascertained by using well-resolved excitation spectra. The nonspecific interaction affects negligibly the Debye-Waller factor and the type of Chi a solvates. However, the width and maximum of the inhomogeneous site-distribution function (as well as absorption and nonselectively excited fluorescence maxima) are related (via dispersion interaction and Stark shift) to the local polarizability and charge density in the closest environment of pigment molecules.