Abstract Systematic variation of the molecular symmetry in a photochromic system based on a 1, 2-bis (2-methylbenzo [b] thiophen-3-yl) hexafluorocyclopentene group, connected by decyl spacers to two cyanobiphenyl groups as mesogens, allows for a systematic investigation of the correlations between molecular shape and symmetry, electronic effects, photochromic conversion and liquid-crystalline properties.