On the other hand, Y6-C5, which has alkyl chains branched in the fifth position, showed a relatively higher face-on orientation than Y6-C4. ). In dimethyl sulfoxide (DMSO) solutions, CSEt and CSPr showed identical patterns of UV-vis absorption at 325 nm. Meanwhile, the fluorescence spectra expressed the same peaks at 400 nm with a low fluorescence quantum yield of 0.3% and 0.5% for CSEt and CSPr, respectively. Those results indicated that the alkyl groups did not affect the electronic structure of the cyanostilbene core.