Experimental and PCM/TD-DFT investigation on the absorption and emission spectra of a light emitting material in various solvents

The ground (S0) and lowest singlet excited state (S1) as well as the absorption and emission properties of a donor-π-acceptor structure molecule, 3-(dicyanomethylene)-5,5-dimethyl-1(4-[(2-hydroxy-ethyl)-methyl-amino]-styryl)cyclohexene (DCDHC), are investigated. The experimental emission spectra in four solvents of different polarity are obtained. The optimization of the geometries for S0 and S1 states are computed by density functional theory (DFT) and time-dependent (TD) DFT. The absorption and emission spectra in solvents are calculated at the TDDFT methods in combination with the polarized continuum model. The performance of ten exchange–correlation functionals is discussed and it turns out that, within the selected TDDFT framework, M06 and PBE0 emerge as the most efficient hybrids for DCDHC molecule.