The photophysical properties of DCzPy were investigated in tetrahydrofuran (THF) solution and aggregated state. As shown in UV-vis spectra, DCzPy showed a main absorption band at 363 nm due to the ICT transition in THF (1.0 10 -5 M) (Fig. ). The PL spectra of DCzPy centered at 480 nm in THF (Fig. ). Then, the PL spectra were performed in different solvents (n-hexane, toluene, dichloromethane, THF, dichloroethane, acetonitrile, ethanol, N, N-dimethyl formamide, dimethylsulfoxide) to study their solvation effect. Due to twisted intramolecular charge transfer (TICT) transition, the absorption band of DCzPy showed obvious bathochromicshift accompanied by emission color changed from blue to green to yellow with increasing the solvent polarity (Fig. ). When keeping the concentration of DCzPy at 4.0 10 -5 M, the PL intensity gradually decreased with enhancement of water (poor solvent) fraction from 0 to 70% in THF solution, meanwhile, the wavelength was bathochromic-shifted to about 540 nm (Fig. ). This phenomenon was also attributed to the TICT effect . During this process, the energy gap between excited state and ground state is decreased to afford red-shifted emission. Meanwhile, the dark state of TICT relaxed to the ground state mainly through non-radiative transition, resulting in decreased emission efficiency. Further increasing the water fraction to 95%, the fluorescence intensity was increased accompanied by a hypsochromic-shift from 540 to 492 nm thanks to formation of uniform and well-ordered aggregates. In addition, frontier molecular orbitals were calculated at the B3LYP/6-311G* level by using density functional theory (DFT). As shown in Fig. , the highest occupied molecular orbital (HOMO) of DCzPy mainly located on the Cz units. In contrast, the lowest unoccupied molecular orbital (LUMO) centered on the dicyanopyridine core. Upon excitation, electrons were transferred from Cz units to the dicyanopyridine group in DCzPy. The energy gap of the LUMO and HOMO was 1.87 eV. The spatial separation of the HOMO and LUMO is beneficial for intramolecular charge transition.