DFT Studies of p-N,N-(Dimethylamino) Benzoic Acid with Para or Meta–Electron Withdrawing or Donating Moieties for Dye-Sensitized Solar Cells (DSSCs)

Table 2

The FMOs (eV), energy gaps (∆E/eV), dipole moments (µ/Debye), and absorption spectra maxima (λ_max/nm) of the gas-phase neat 4-DMABA and 4-DMABA-T⁺⁴(OH)₄ complex which was calculated by using different DFT functionals with 6–311++G basis set.

Parameters	B3LYP		CAM-B3LYB		PBEPBE		ωB97XD
	D1	D2	D1	D2	D1	D2	D1	D2
LUMO+2	−0.477	−1.279	0.583	0.094	−0.838	−1.966	1.260	0.715
LUMO+1	−0.543	−1.520	0.131	−0.057	−1.217	−2.222	0.858	0.597
LUMO	−1.165	−1.906	0.104	−0.486	−1.860	−2.592	0.751	0.157
HOMO	−5.759	−5.812	−7.067	−7.087	−5.006	−5.081	−7.580	−7.615
HOMO-1	−7.187	−7.221	−8.672	−8.682	−6.129	−6.418	−9.210	−9.222
HOMO-2	−7.556	−8.027	−9.359	−9.630	−6.366	−6.587	9.811	−10.123
∆E	4.594	3.906	7.171	6.601	3.146	2.489	8.331	7.772
µ	5.164	6.277	4.883	5.829	5.356	6.686	4.822	5.705
λ max	290.1	356.6	267.2	275.2	321.5	470.5	265.2	270.2