Thermally reversible fluorescent polymorphs of alkoxy-cyano-substituted diphenylbutadienes: role of crystal packing in solid state fluorescence

Correlation of fluorescence and crystal packing in thermally interconvertible polymorphic states of octyloxy-cyano-substituted diphenylbutadiene possessing visually distinguishable fluorescence reveals that solid state fluorescence of this class of derivatives depends on their monomer-J-aggregate ratio, controlled by variations in their molecular packing.