基于分子内质子转移的敏感变色双水杨醛缩芳胺类化合物

Thermochromic and photochromic salicylidenedimine based on intermolecular proton transfer

通过芳胺芳醛缩合反应制备 6种敏感变色双水杨醛缩芳胺类化合物 ,用红外光谱、紫外光谱、熔点、元素分析等对产物进行表征 ,研究表明这些化合物在固态均具有热致变色性质 ,热致变色晶体中分子为平面 ,面对面堆积排列 ,分子之间距离较小 ,而光致变色晶体中分子的水杨醛亚胺平面与芳胺环平面之间有一个夹角 .

Six salicylidenedimine derivatives with different substitutients were obtained from direct condensation of the appropriate salicylaldehyde with the appropriate diamine in ethanol, followed by repeated recrystallization. IR, UV, melting points and elemental analysis were utilized to establish the purity of the compounds. Salicylidenedimine derivatives were investigated for their thermochromic and photochromic properties in the solid state. All compounds were found to be thermochromic. On the basis of structural studies it is concluded that in thermochromic crystals the molecules are essentially planar and packed face to face with short intermolecular distances but in the photochromic form, the aniline ring is twisted about the exocyclic N C bond. The coloration processes of salicylidenedimine derivatives involve a quick transfer of intermolecular proton.