The reaction of 4'-hydroxy-4-methyl azobenzene (1) and 1,6-dibromohexane afforded 6-bromo-1-((4- ((4-met hylphenyl)azo)phenyl)oxy)hexane (2),which further reacted with p-tert-butylcalix[4]arene to give the calix[4]arene derivative (3) whose lower rim had been modified by the azobenzene photochromic group.The structure of 3 was characterized by 1H-nuclear magnetic resonance (NMR) and electrospray ionization-mass spectrometry (ESI-MS).The fluorescence intensity of compound 3 was two to four times higher than that of compounds 1 and 2 as the azobenzene group concentration in the range of 1.6 x 10-5 to 8.0 ×10-4 mol/L,indicating that the fluorescence quantum yield of the azobenzene group had been improved through being attached to the calix[4]arene skeleton.The liquid crystalline behavior of compound 3 was studied by polarized microscopy (POM) and differential scan calorimeter (DSC).Compound 3 exhibited the enchased texture ofa smectic liquid crystal from 209.4℃ to 219.5℃ on heating,while 2 exhibited a liquid crystalline phase from 87.4 to 83.2℃ on cooling.It was found that the calix[4]arene skeleton was a good platform for conformation immobilization ofazobenzene photochromic group and the formation of liquid crystalline.
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