Mono- and di-t-butyl substituted 2,2'-bis(1,3-dithia[3]ferrocenophane-2-ylidene) derivatives were prepared. These derivatives showed the E-1/2(1) in lower potential region than that of differrocenyl-ethene and -ethyne. Also, the Delta E-1/2 value declined according to the increase of a t-butyl group. (C) 2007 Elsevier B.V. All rights reserved.