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Photochromism and Thermochromism of Zeolite Spramolecules

沸石分子筛的光致变色和热致变色

基本信息

批准号：
15550029
负责人：
KOJIMA Masanobu
金额：
$ 2.43万
依托单位：
Shinshu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

项目摘要

(1)Published in J.Phys.Org.Chem.18, 994-1000 (2005) : The half-life (τ_<1/2>) for thermal isomerization of cis-4-hydroxyazobenzene (c-HOAB) to its trans isomer is highly dependent on the solvent used. For non-aromatic solvents, the cis isomer is extremely unstable at 293 K (τ_<1/2> < 1 min in methanol and acetonitrile ; 6 min in cyclohexane), while the cis isomer is surprisingly stable in benzene (τ_<1/2> = 125 min). However, addition of hydrogen chloride and triethylamine in benzene causes a remarkable decrease in τ_<1/2>. On the basis of ab initio molecular orbital calculations of the binding energies and the optimum structures of c-HOAB-solvent complexes, a mechanism for the thermal cis-to-trans isomerization reaction involving hydrogen-bonded dimers and complexes is suggested.(2)Published in Chem.Phys.Lett., 408, 197-204 (2005) : To elucidate the stable structures and electronic properties of hydrogen-bonded 4-hydroxyazobenzene (HOAB) dimers, we performed ab initio molecular orbita … More l calculations based on the density functional theory. The obtained stable structures and total energies for the fifteen types of dimers indicate that the trans-trans HOAB dimers are at least 10 kcal/mol more stable than the other cis-cis, cis-trans and trans-cis dimers. In addition, it was found that the dimer of tautomerized trans-HOAB has similar stability to the trans-trans HOAB dimers, suggesting that the tautomerized trans-HOAB dimer contributes to the unique photochemical and spectroscopic behavior of HOAB.(3)Published in Res.Chem.Intermed., 30, 181-190 (2004) : In the photostationary state, the cis/traps isomer ratio of azobenzene and 3,3'-dimethylazobenzene adsorbed in zeolite NaY increases significantly to ca. 90/10 in contrast to the reaction in cyclohexane. However, for azobenzene-4,4'-dicarboxylic acid diethyl ester the formation of the cis isomer is remarkably suppressed to ca. 30%. On the basis of ab initio MO calculations, it is suggested that electrostatic interaction between these azobenzenes and the metal ions in zeolite nanocavities regulates the cis-trans photoisomerization process. In addition, it is found that the photoisomerization behavior of azobenzenes adsorbed on silica gel is similar to that in NaY.(4)Research related to this study was reviewed in Handbook of Photochemistry and Photobiology (2003) and also Encyclopedia of Nanoscience and Nanotechnology (2004). Less

（1）发表于J.Phys.Org.Chem.18，994 - 1000（2005）：顺式-4-羟基偶氮苯（c-HOAB）热异构化成其反式异构体的半衰期（τ_<1/2>）高度依赖于所用溶剂。对于非芳香族溶剂，顺式异构体在293 K时极不稳定（在甲醇和乙腈中τ <1/2><1 min;在环己烷中τ <6 min），而在苯中则非常稳定（τ <1/2>= 125 min）。而在苯中加入氯化氢和三乙胺则使τ <1/2>显著降低。基于从头计算的结合能和c-HOAB-溶剂配合物的最佳结构的基础上，热顺反异构化反应涉及氢键二聚体和配合物的机制建议。（2）发表于Chem.Phys.Lett.，408，197 - 204（2005）：为了阐明氢键键合的4-羟基偶氮苯（HOAB）二聚体的稳定结构和电子性质，我们进行了从头算分子轨道计算， ...更多信息 l基于密度泛函理论的计算。15种二聚体的稳定结构和总能量表明，反-反HOAB二聚体比其它顺-顺、顺-反和反-顺三种二聚体稳定至少10 kcal/mol.此外，发现互变异构的trans-HOAB二聚体具有与trans-transHOAB二聚体相似的稳定性，这表明互变异构的trans-HOAB二聚体有助于HOAB独特的光化学和光谱行为。（3）发表于Res.Chem.Intermed.，30，181 - 190（2004）：在光稳定状态下，吸附在沸石NaY中的偶氮苯和3，3'-二甲基偶氮苯的顺式/陷阱异构体比率显著增加至约100。90/10，与在环己烷中的反应相反。然而，对于偶氮苯-4，4'-二羧酸二乙酯，顺式异构体的形成被显著抑制至约100%。百分之三十从头算分子轨道计算的基础上，这些偶氮苯和沸石纳米腔中的金属离子之间的静电相互作用调节顺-反光异构化过程。此外，发现偶氮苯在硅胶上的光异构化行为与在NaY中的相似。（4）与本研究相关的研究在Handbook of Photochemistry and Photobiology（2003）和Encyclopedia of Nanoscience and Nanotechnology（2004）中进行了综述。少