136018-82-1Relevant academic research and scientific papers
Z-isomers of 3,3'-disubstituted azobenzenes highly compatible with liquid crystals
Ruslim, Christian,Ichimura, Kunihiro
, p. 673 - 681 (1999)
It is known that mesophase changes can be induced by E-Z photoisomerization of azobenzenes doped in liquid crystals. Novel azobenzenes have been designed on the basis of Molecular Mechanics and Molecular Orbital calculation, aimed at exploiting novel photoresponsive guest-host liquid crystalline systems exhibiting no mesophase change despite the drastic structural alteration of the guest molecules. It was found that the introduction of alkanoyloxy groups at both the 3- and 3'-positions of azobenzene leads to phase stability of nematic systems upon the E-Z photoisomerization even at a dopant concentration as high as 20 wt%. However phase separation was brought about when 3,3'-dialkoxyazobenzenes and 4,4'- dialkoxyazobenzenes were employed as guest molecules. The relation between the conformational structures of the guests in their E- and Z-isomers and their compatibility with nematic hosts was examined thermodynamically. Experimental results were compared in some details with the simulations. It was shown that 3,3'-dialkanoyloxyazobenzene prefers a rod-like structure in both E- and Z-isomers.
Fusion of photochromic reaction and synthetic reaction: Photoassisted cyclization to highly strained chiral azobenzenophanes
Takaishi, Kazuto,Kawamoto, Masuki,Muranaka, Atsuya,Uchiyama, Masanobu
, p. 3252 - 3255 (2012)
A method for synthesizing highly strained cyclic structures by combining photochromic and synthetic reactions is described. Tightly linked azobenzene-binaphthyl dyads (R)-4 and (R)-6 could not be obtained by conventional cyclization, but continuous application of photoirradiation, which induced (E)→(Z) isomerization of the azobenzene moiety, allowed the cyclization reaction to proceed, affording the desired chiral azobenzenophanes.
Z-isomers of azobenzenes highly compatible with liquid crystals
Ruslim, Christian,Ichimura, Kunihiro
, p. 789 - 790 (2007/10/03)
Novel guest-host liquid crystal systems containing 3,3-disubstituted azobenzenes as guests were prepared on the basis of molecular design by molecular calculations to achieve the improvement of compatibility of the chromophore with nematic phases. No phase change of nematic liquid crystals was induced by the E-to-Z photoisomerization of the guests even at doped concentrations as high as 20 wt%.
