FIGURE 1.

Photophysical properties of ht-PLP_PAN (A) Experimental and simulated UV-vis spectra of ht-PLP_PAN calculated by time-dependent density functional theory (TDDFT). Structure optimization and TDDFT calculations were performed in simulated water environment using a polarizable continuum model, at the ωB97X-D/6-31g-d and cam-b3lyp/6-31g-d levels, respectively (B) A representative model structure for photoactive domains of ht-PLP_PAN with four nitrogen atoms (oI₄), optimized at the ωB97X-D/6-31g-d level (Stephens et al., 1994; Frisch et al., 2016). (C) Energy levels of the lowest unoccupied molecular orbital (LUMO, black bars) and wavelengths of the lowest energy transition (red squares) of model structures (oI₃ to oI₁₀) with different conjugation lengths represented by the number of nitrogen atoms within the backbone (Sun et al., 2020). The dashed line represents the energy of the LUMO (β) of the [Br-Cu^II/TPMA]⁺ complex in water [optimized at the ωB97X-D level with def2TZVP basis set on Cu and 6-31g-d basis set on the other atoms (Miertuš and Tomasi, 1981; Chai and Head-Gordon, 2008)].