| 摘要 |
<p>Molecules with a group X which attracts electrons and comprises pi -electrons and conjugated therewith a group R which supplies electrons, of the formula R - X in which X represents -COCF3, -COC6H5 or -SOnCF3, n being 0 or 2, and R represents phenyl or (CH3)2N, as electrooptically active liquid inter alia have the advantage that they are achromatic compared with nitrobenzene.</p> |
