**3. Application for chiroptical polymer film**

*Current Topics in Chirality - From Chemistry to Biology*

On the basis of this finding, we applied a binary method wherein an existing non-chiral fluorescent dye was incorporated into a molecular gel as a chiral template for CPL generation. This method is advantageous because it is not necessary to introduce chirality into the fluorescent dye, because of which, the degree of freedom in synthetic chemistry is greatly increased. In addition, the light emitting region of the CPL can be easily tuned by proper selection of the dye. As a result, the highest value in CPL (|**g**lum| > 0.1) was obtained using a molecular gel from

*Example of induced CPL by a binary system constructed of non-chiral fluorescent dye with chiral molecular gel template. (a) CPL spectra of anthracene, phenylanthracene, and diphenylanthracene in the presence of G-Py<sup>+</sup> in aqueous solutions at 2 °C. Excitation wavelength was 340 nm. [Anthracene derivertives] = 12.5 µM. [G-Py<sup>+</sup>*

 *with fluorophores. The concentrations of G-Py<sup>+</sup>*

*= 0.5 mM. [81] - reproduced by permission of the Chemical Society of Japan (CSJ). (b) Tunability of CPL emission bands. Blue, green, and red CPL spectra were obtained with (i) pyrenesulfonic acid, (ii) Yellow dye, and (iii) NK*‐*2012, respectively. All the CPL spectra were measured in aqueous systems at 20°C in the presence* 

*0.5 mM and 12.5 μm, respectively. The excitation wavelengths were 330, 420, and 500 nm in pyrenesulfonic acid, Yellow dye, and NK-2012. All the CPL spectra were normalized at the highest peak of the fluorescence emissions corresponding to the CPL signals. [24] - reproduced by permission of John Wiley and Sons.*

*]* 

 *and the fluorophores were* 

 as a chiral template with a hydrophobic fluorescent dye such as anthracene (**Figure 14a**) [81] and an anionic cyanine-based fluorescent dye (**Figure 14b**) [24] combined. **Figure 14b** also shows that the emission wavelength can be easily tuned by selecting pyrene sulfonic acid or yellow dye as the fluorescent dye and that the positive and negative can be reversed by the enantiomers of the template [24]. The other example of CPL generation is presented by **Figure 15** [111]. In this case, the *G-***COOH**-based molecular gel having a carboxyl group is used as a chiral template, considering solubility in a non-aqueous solvent. It was confirmed that the induced CD and the induced CPL were expressed in the binary system combined with the cationic dye. However, in this case, it was also confirmed that the coexistence of a base such as triethylamine in the solution significantly improved

*Induction of CD and CPL in non-aqueous molecular gel system. [111] - reproduced by permission of the Royal* 

**120**

**Figure 15.**

*Society of Chemistry.*

*G-***Py<sup>+</sup>**

**Figure 14.**

*of L*‐ *and D-enantiomers of G-Py<sup>+</sup>*
