Photoisomerization Characteristics Of Organics Containing Main-chain Azobenzene

The synthesis and properties of small azobenzene molecules are the basis for the synthesis and properties of organic compounds containing azobenzene structural units in the main chain.Azobenzene structure can achieve cis-trans configuration change under the light stimulation of 365 nm and 430 nm when the trans configuration of the azobenzene molecule converted to the cis configuration,the distance between the two carbon atoms in the para position of the benzene ring substituent reduced from 9.0 (?) to5.5 (?).Polymers containing azobenzene structural units in the main chain may amplify this change.Organic substances with this property have great application prospects in light-driven materials such as artificial muscles.The photoisomer of fumaramide structure also has the characteristics of photodeformation.Fumaramide structure can achieve cis-trans configuration change under the light stimulation of 254 nm and 312 nm,and the distance between its two amino groups will also change.Organic substances containing azobenzene structural units or fumaramide structural units in the main chain may amplify this change when photoisomerization occurs.Organic compounds with this property have excellent application prospects.Organic compounds with both azobenzene structural units and fumaramide structural units on the main chain will have more enormous advantages in terms of photodeformation.The main research contents of this article are as follows:1.4,4'-dibromoazobenzene(DBAB)synthesized using 4-bromoaniline as raw material.Using DBAB and 4-n-octylaniline as raw materials to obtain poly(azobenzeneoctylaniline)(PABOA).A new polymerization method is selected and reacted in a common solvent under a closed air atmosphere to obtain PABOA with a molecular weight greater than 10,000.Draw a ball and stick model of PABOA.Using 1H NMR as the detection method,DBAB and PABOA characterized.The effect of reaction time on conversion rate and the particle size of reaction additives on the yield of DBAB synthesis reaction were discussed.The effects of changes in solvent grade and reaction atmosphere on polymerization discussed.UV-Vis absorption spectrum used as a detection method to characterize the photoisomerization of DBAB and PABOA under different light conditions and verify the cis-trans isomerism of DBAB's and PABOA's light response.Characterize the UV absorption changes of DBAB and PABOA in different polar solutions and solutions with different p H values,and make a reasonable explanation.2.Design poly(azobenzene-fumaramide)oligomer(PABFM)molecules with two types of photo-responsive groups to draw the ball and stick models under different isomerism states.Fumaramide derivatives(DHFM)synthesized from fumaric chloride and n-hexylamine,and PABFM with dual light response properties was designed and synthesized using DHFM and DBAB as monomers.Using 1H NMR as the detection method,DHFM and PABFM characterized.UV-Vis absorption spectrum used as a detection method to characterize the photoisomerization of DHFM and PABFM under different light conditions and verify the cis-trans heterogeneous nature of PABFM's dual light response.Compare the ultraviolet absorption changes of DHFM in different light conditions and different polar solutions,and make a reasonable explanation.