Metal dithiene derivatives and a process for preparing them.

摘要

A metal dithiene of the formula:
<Chemistry id="chema01" num="0001"><Image id="ia01" he="46" wi="85" file="IMGA0001.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>wherein R<Sup>1</Sup> is C<Sub>3</Sub> to C<Sub>20</Sub> alkyl;
<UnorderedLists id="ula01" listStyle="none"><ListItem>R<Sup>2</Sup> is selected from alkyl, alkylamino, dialkylamino, alkylthio and alkoxy in which each alkyl contains up to 20 carbon atoms;</ListItem><ListItem>R<Sup>3</Sup> is H, halogen or a group represented by R<Sup>2</Sup>; and</ListItem><ListItem>M is a metal selected from Groups Ib, Ilb, Vllb, and Vlllb of the Periodic Table, and a composition of the metal dithiene in a liquid crystal medium. The composition is suitable for use in a light valve for a laser-addressed liquid crystal display.</ListItem></UnorderedLists>