Synthesis And Liquid Crystal Properties Of Azobenzene Compounds Containing 1,2,3-Triazole

Liquid crystal compounds are widely used in many fields such as information recording,liquid crystal display,optical transformation and composite materials due to their unique photoelectric effect.Aromatic azo compounds have large ? electron systems,further enlarged conjugated systems,and good optical properties.1,2,3-triazole compounds are a kind of important nitrogen-containing heterocyclic compounds,which have been widely used in drug research,material chemistry and other fields.In this paper,a series of triazole heterocyclic azobenzene compounds with different substituents were constructed and their liquid crystal properties were studied.It is expected that more useful liquid crystal compounds can be found.In this paper,a series of triazole heterocyclic azobenzenes containing different end groups were synthesized starting from p-nitrophenol by diazotization,dehydration and Click reaction.The compounds were characterized by NMR spectroscopy and infrared spectrometry(IR).The electrochemical properties of triazole heterocyclic azobenzene containing ferrocene group were studied by cyclic voltammetry(CV).The spectroscopic properties of the compound were tested by ultraviolet visible spectrum(UV)and fluorescence spectrum,and the synthesized compound can undergo cis-trans isomerism under light control.Differential scanning calorimety(DSC)and orthogonal polarization microscope(POM)were used to test the liquid crystal properties.The results showed that the long chain triazolazobenzene compound series and the long chain triazolazobenzene compound series with ferrocene are all presented as smectic liquid crystals.With the increase of the end group carbon chain,the mesocrystalline range of the long chain triazolazobenzene compound series gradually increases.The melting point of the series of ferrocene long chain triazole azo compounds are lower,and the mesocrystalline interval was larger.The compound 8CSZF11 has the widest mesocrystalline range at 102 ?.