Synthesis And Photochromism Properties Of Novel Azobenzene Derivates

Substituted azobenzene derivatives are important intermediates in the synthesis of dyes. The interest of azobenzene derivatives originates in a wide rang of potential application. They have been the most widely used class of dyes due to their versatile features in various field, such as dyeing textile fiber, bio-medical studies, information storage, optical memory and processing, waveguide switch, etc. In this thesis, six novel azaobenzene derivates were designed and synthesized.Their structures were determined by FT-IR, NMR and Element Analyze. The results were in according with the respected structure.The UV-Vis absorption spectrum and fluorescent spectrum of these azobenzene derivates were measured. The results showed that there was bathochromic of the maximum absorption wavelength with the increasing of solvent polarity. The fluorescent spectrum approved that there were the hydrogen bonds between the adjacent position groups and the hydrogen bonds would stabilize cis-structure. The photochromism properties of these azobenzene derivates in different solvents were studied. The final results indicated that HDBA in weak polar solvents had quick isomerization rate, good repeatability and low energy loss. The space steric effect of substituent, hydrogen bond between adjacent hydrogen group and nitrogen atom, dipole-dipole effect among atoms and hydrogen bond effect among adjacent position groups would influence the cis-trans isomerism of azobenzene derivates in solvents.The adjacent hydrogen azaobenzene derivates had quick isomerization rate in weak polar solvents. The hydrogen bond effect between adjacent groups would stabilize the cis-structures. It indicated that the photochromism behave of azobenzene derivates would be controlled by adjusting the solvents and intramolecular hydrogen bond. The unique properties of orth-azobenzene derivatives expand their application field in photo chromic polymer.