188185-74-2Relevant academic research and scientific papers
Z-isomers of azobenzenes highly compatible with liquid crystals
Ruslim, Christian,Ichimura, Kunihiro
, p. 789 - 790 (1998)
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%.
Z-isomers of 3,3'-disubstituted azobenzenes highly compatible with liquid crystals
Ruslim, Christian,Ichimura, Kunihiro
, p. 673 - 681 (2007/10/03)
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.
Total syntheses of the slime mold alkaloid arcyriacyanin A
Brenner, Michael,Mayer, Guido,Terpin, Andreas,Steglich, Wolfgang
, p. 70 - 74 (2007/10/03)
Arcyriacyanin A (1) has been synthesized by three different routes. In the first synthesis the bisbromomagnesium salt of 2,4'-biindole (5) was treated with dibromomaleimide (6) to yield arcyriacyanin A (1). The second approach used an intramolecular Hock
