Toward multi-addressable molecular systems: Efficient synthesis and photochromic performance of unsymmetrical bisthienylethenes

Various synthetic routes have been compared to access to unsymmetrical 1,2-bisthienylperfluorocyclopentenes having one electro-withdrawing formyl group. The strategy based on key monosusbtituted cyclopentenes appears to be the most reliable and versatile synthetic approach. Applying this controlled sequential synthesis to appropriate thiophenic building blocks leads to the preparation of π-conjugated extended push–pull system where photochromic performance were characterised.