Studies on elucidation of isomerization reaction of Schiff bases crystals and construction of novel proton flux. supramolecular systems

实验发现了N-水杨酰亚胺晶体的顺式酮光产物。利用N-水杨酰亚苯胺次羟基衍生物的光致变色物种的热褪色反应，观察到固态中的氘同位素动力学效应：实验表明，光色席夫碱晶体中存在顺式-酮式化合物，同时6-甲基取代对光产物的稳定性有影响。本文制备了2，6-二烷基取代苯胺席夫碱crystals.N-(3，5-Dihalosalicylidene)-2，6-dialkylaniline衍生物，并研究了它们的结构和光致变色性能。X-射线单晶分析表明，甲亚胺氢原子与苯胺环2，6-位烷基之间的空间斥力导致了非平面的分子结构，这对晶体的光致变色是有效的。讨论了N-(3，5-dichlorosalicylidene)-2，6-dialkylanilines系列的光致变色性与晶体堆积的关系。提出了用2，6-二烷基苯胺法合成水杨醛环上不同取代基光致变色希夫碱的方法，合成了多晶型4，4‘-methylenebis(N-salicylidene-2，6-diisopropylaniline)crystals.4，4’-Methylenebis(N-salicylidene-2，6-dialkylaniline)衍生物的光致变色性，并用1H核磁共振、红外光谱、差示扫描量热法和X-射线单晶分析对其结构进行了表征。2，6-二异丙基苯胺衍生物得到了一定的多晶型晶体，其空间群分别为C2/c和P21/n。结果表明，两种晶型具有相似的光致变色性，但由于晶体中分子形状和空穴的不同，光致变色剂的热稳定性不同。

Experimantal finding of a cis-keto photoproduct derived from N-salicylideneaniline crystal.Deuterium isotope kinetic effect in the solid state was observed by using thermal fading reaction of photo-coloured species derived from N-salicylideneaniline deuterohydroxyl derivative : thus, the existence of a cis-keto form in the photocoloured Schiff base crystals was suggested experimentally along with 6-methyl-substitution effect on the stability of the photoproduct.Advantage of 2,6-dialkyl substituents of aniline for preparation of photochromic Schiff base crystals.N-(3,5-Dihalosalicylidene)-2,6-dialkylaniline derivatives were prepared and their structure and photochromic properties were investigated. From the X-ray crystallography, it was revealed that steric repulsion between the azomethine hydrogen atom and the alkyl groups at the 2,6-positions of the aniline ring lead to a non-planar molecular structure, which was effective for the crystals to exhibit photochromism. The relationship between photochromicity and crystal packing of N-(3,5-dichlorosalicylidene)-2,6-dialkylanilines series was also discussed. The 2,6-dialkylaniline method was suggested to be applicable to the preparation of photochromic Schiff bases with various substituents in the salicylidene rings.Photochromism of polymorphic 4,4'-methylenebis(N-salicylidene-2,6-diisopropylaniline) crystals.4,4'-Methylenebis(N-salicylidene-2,6-dialkylaniline) derivatives were prepared and their structures were determined by ^1H NMR,IR,DSC and X-ray crystallographic analyses. The 2,6-diisopropylaniline derivative yielded definite polymorphic crystals : the space groups of the crystals were C2/c and P2_1/n, respectively. It was found that both polymorphs were similarly photochromic but the thermal stability of the photochrome was different due to the variance of the shape of molecule and cavity in each crystal.