α, α′-Bis (substituted-benzylidene) cycloalkanones were synthesized via a solvent-free cross-aldol condensation of aromatic aldehydes with cycloalkanones in the presence of a catalytic amount 1-methyl-3 (2-(sulfooxy) ethyl)-1 H-imidazol-3-ium chloride at room temperature with excellent yields. The screening for optical properties indicated that the size of cycloalkanone has an influence on the fluorescence emission of products. Products ...