Synthesis And Properties Of Photochromic Compounds Based On Diarylethene

In the era of globalization,the rapid development of society is inseparable from the existence of information,followed by the increasing demand for massive information storage and high-speed transmission.The photoelectric materials with high efficiency and security information storage and transmission function have attracted more attention of scholars.The design and preparation of organic photochromic materials with high performance play a decisive role in the development of optoelectronic information.Diarylethenes are widely used in various fields of research and design due to their flexible reaction characteristics,low cost,stable structure and other excellent properties.This paper aims to develop a series of monomolecular materials with multiple functions based on diarylethenes,expanding the research in related fields and further exploring their applications in related fields.First,we synthesized a novel Schiff base gated photochromic molecule DTEP with dithiophene ethylene as the core unit and 2-pyridyl hydrazide as the recognition group.The traditional photochromic effect would occur in methanol solution of DTEP with the irradiation of UV light.The photochromic properties of compound DTEP could be inhibited completely by the introduction of Cu²⁺to form a 1:1 complexation,while the weak gated photochromism could be found from the complex in a 1:2 stoichiometry.We analyzed the complexation of imine and carbonyl groups with Cu²⁺and Ni²⁺will change the molecular orbital energy level,and then change the connection characteristics between the two thiophene active carbon atoms,thus losing the photoinduced ring-closed ability of the molecule.This is a kind of classical gated photochromic molecular switch mechanism.Relying on such varying degrees of gated photochromic properties,a new molecular logic circuit was constructed to undertake complicated logical operations.Secondly,we designed a series of novel molecules N1 and N2 based on dithiophene ethylene with nitroso group as recognition.There is no photochromism could be found upon the irradiation of UV light.However,it is found that only N1 with nitroso group on one side has strong recognition ability for Cu²⁺.It is possible that the introduction of nitroso group affects the ring-closed process of thiophene ethylene.The push-pull electron ability of nitroso group makes the compound has strong complexation effect on Cu²⁺.This high selectivity enables N1 to specifically recognize Cu²⁺.It is expected to be applied to ion probes or chemical sensors in the future.Finally,we discussed the development status of this new organic photochromic material based on diarylethene.Based on the analysis of the diaryl ethylene derivatives,the prospect of designing molecules according to the actual needs of production and application in various industries is put forward.And make it form a ring-closed mode from demand to application.It is of great significance for us to develop new smart materials in the field of photochromism.