Fig. 2. (a) Absorption spectra and (b) PL emission spectra of aqueous NP2C, NP4C, NP6C, PC, NPM and NPMC solutions; (c) PL excitation spectra for dual emission of NP4C, respectively, monitored at 455 and 550 nm. (d) PL emission spectra of NP4C measured at various excitation wavelengths. (e) Calculated frontier molecular orbitals of NP4C and NPM. [NP2C] = [NP4C] = [NP6C] = [NPM] = [PC] = [NPMC] = 25 μM.
