The synthesis and properties of ferroceno[1′,2′;1″,2″]bis(1,3-dithiol-2-thione and -2-one) derivatives

The t-butyl and bis(t-butyl) derivatives of hexathia[3.3]ferrocenophane were prepared from the corresponding trithia[3]ferrocenophanes. The former was a mixture of chair–chair and chair–boat isomers, and the latter existed only chair–boat isomer. The hexathia[3.3]ferrocenophanes were led to the tetrathiols with LiAlH4, which allowed to react with 1,1′-thiocarbonyldiimidazol to give the corresponding ferroceno[1′,2′;1″,2″]bis(1,3-dithiol-2-thione) derivatives. Mono t-butyl and unsubstituted analogs were prepared in a similar manner. The X-ray structural determination showed that these derivatives adopted the conformation in which the 1,3-dithiol-2-thione rings were heaped on top of each other. In the crystal of ferroceno[1′,2′;1″,2″]bis(1,3-dithiol-2-thione), the molecules packed so as to put the axis of molecule in order and to overlap one another above and below. The desulfurizative coupling of the ferroceno[1′,2′;1″,2″]bis(1,3-dithiol-2-thione) derivatives was unsuccessful.