Figure 6 Comparative Simulation Absorption Spectra of Heterocyclic Modification and Aminoethylamino Introduction Obtained by ωB97XD/6-311G(d,p) Calculation in Dichloromethane
In Figure 6 we depicted the simulated absorption spectra of heterocyclic modification and amino-ethyl-amino inclusion to explore the influence of amino-ethyl-amino introduction on the absorption spectra of dye molecules. It can be seen in Figure 6 that the maximum absorption peak of MTPA-APyc molecule is significantly blue-shifted compared with MTPA-Pyc. However, since the second absorption peak and the maximum absorption peak are fused together to form a shoulder peak at the maximum absorption peak, the width of the absorption band is increased. The maximum absorption peak position of the MTPABT-APyc molecule is the same as that of the MTPA-APyc molecule, the absorption peak width is increased but the intensity is decreased compared with MTPABT-Pyc. The positions of the maximum absorption peaks of MTPAQL-APyc, MTPABD-APyc, and MTPAPA-APyc molecules are significantly red-shifted after the introduction of aminoethylamino group, and the maximum absorption peaks of MTPADP-APyc and MTPABD-APyc molecules are red-shifted to around 500 nm. However, the intensity of the absorption peak is reduced, which is not conducive to the absorption of sunlight by the dye. Moreover, a second absorption peak with a large absorption intensity appears in the absorption spectra of MTPADP-APyc, MTPAQL-APyc, MTPABD-APyc and MTPAPA-APyc dye molecules.
Table 3 Calculated maximum absorption wavelength (λmax=nm), excitation energy (E),oscillator strengths (f) , light harvesting efficiency (LHE(λmax)) and electronic transition contributions of designed dyes in dichloromethane