Photochromism and Thermochromism of Zeolite Spramolecules

(1)发表在J.Phys.Org.Chem.18994-1000中(2005年)：顺-4-羟基偶氮苯(c-HOAB)热异构化为其反式异构体的半衰期(τ_&lt；1/2&gt；)高度依赖于所使用的溶剂。对于非芳香族溶剂，顺式异构体在293K时极不稳定(τ_&lt；1/2&gt；1/2&lt；1min；在环己烷中为6min)，而顺式异构体在苯中非常稳定(τ_&lt；1/2&gt；=125min)。而在苯中加入氯化氢和三乙胺后，τ_1/2&gt；显著降低。在从头算分子轨道计算c-HOAB-溶剂络合物的结合能和最佳结构的基础上，提出了氢键二聚体和络合物的热顺反异构化反应机理。(2)发表在《化学物理》，408,197-204(2005)：为了阐明氢键对羟基偶氮苯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…更多的是基于密度泛函理论的L计算。15种二聚体的稳定结构和总能量表明，反式HOAB二聚体比其他顺式、顺式和反式顺式二聚体的稳定性至少高10千卡/摩尔。此外，还发现互变异构化的反式HOAB二聚体与反式HOAB二聚体具有相似的稳定性，这表明互变异构化的反式HOAB二聚体有助于HOAB独特的光化学和光谱行为。(3)发表在Res.Chem.Intermed，30,181-190(2004)上：在光固定状态下，偶氮苯和3，3‘-二甲基偶氮苯在NaY沸石上吸附的顺式/陷阱异构体比显著增加到约90/10，与在环己烷中的反应相反。而对于偶氮苯-4，4‘-二羧酸二乙酯，顺式异构体的生成被显著地抑制到30%左右。在从头计算的基础上，我们认为这些偶氮苯与分子筛纳米腔中的金属离子之间的静电相互作用对顺反光异构化过程起调节作用。此外，还发现偶氮苯在硅胶上的光异构化行为与NaY相似。(4)在《光化学与光生物学手册》(2003)和《纳米科学与技术百科全书》(2004)中综述了与本研究相关的研究。较少

(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