基于芳叉丙二腈的高活性迈克尔系统的吸湿反应及荧光性质

Moisture Absorption Reaction and Fluorescence Property of Highly Active Michael System Based on Arylidenemalononitrile

建立了一个基于芳叉丙二腈的高活性迈克尔系统2,2′-[(5-叔丁基-2-羟基-1,3-苯撑)二甲川]双丙二腈(1),能迅速吸收空气中的水,生成稳定的氧杂迈克尔加成产物2-[5-叔丁基-3-(2,2-二腈基-1-羟乙基)-2-羟基苄叉]丙二腈(2).在二甲亚砜(DMSO)中,各种碱性催化剂都能使化合物2脱水生成化合物1,同时发射红色强荧光.在PBS缓冲溶液(pH=10)中,化合物2立即脱水生成化合物1,随后又缓慢加水转变为化合物2.加热吸附在硅胶上的化合物2的荧光由蓝色变为红色,温度降低后荧光又恢复为蓝色.因此,吸附了化合物2的硅胶可能发展成为一种热敏荧光材料.此外,吸附了化合物1的硅胶还对某些有机蒸汽具有荧光响应.

The phenols and alcohols as nucleophiles are common in oxa-Michael reaction,while H;O normally cannot react with Michael system 2,2′-{[5-(tert-butyl)-2-hydroxy-1,3-phenylene]bis(methaneylylidene)}dimalononitrile(1)was reported,which could rapidly absorb water in the air to afford a stable 2-[5-(tert-butyl)-3-(2,2-dicyano-1-hydroxyethyl)-2-hydroxybenzyli-dene]malononitrile(2)via oxa-Michael addition.The high activity of compound 1 resulted from the synergistic effect among the two dicyanovinyl groups and the one hydroxyl group.In dimethyl sulfoxide(DMSO),compound 2 could quickly dehydrate to give compound 1 in the presence of various alkaline catalysts.In PBS buffer(pH=10),compound 2 immediately converted to compound 1,and then converted back to compound 2 slowly.When heat the silica gel plate loading compound 2,the fluorescence conversion from blue to red were observed.Hence,compound 2 adsorbed on silica gel might be developed into a thermosensitive fluorescent material.In addition,compound 2 adsorbed on silica gel showed fluorescence responses to some organic vapors.