Synthesis of donor-acceptor type 2D porphyrin based cyclic imides as an efficient photo catalysts in DSSC solar cell

Porphyrinated dimides-based materials differing in the nature of dianhydries namely TPP-2(FDI)-TPP and TPP-2(PMDI)-TPP has been synthesized and thoroughly characterized through various techniques including elemental analysis, FT-IR, UV–vis, ¹H NMR spectra, fluorescence studies, and cyclic voltammetry. Furthermore, computational studies were also performed to investigate the electron transfer phenomena in TPP-2(FDI)-TPP and TPP-2(PM DI)-TPP. The 79.1% fluorescence intensity was reduced for TPP-2(FDI)-TPP and 95.8% was reduced for TPP-2(PMDI)-TPP as compared to cis-DATPP indicating the covalent interaction between the porphyrin moiety and dianhydrides, also indicating the transfer of an electron from cis-DATPP to dianhydrides. The HOMO, and LUMO level values for TPP-2(FDI)-TPP and TPP-2(PMDI)-TPP obtained from cyclic voltammetric analysis are −6.665 eV, −6.765 eV and −4.805 eV, −4.915 eV respectively. The HOMO and LUMO level values calculated through computational analysis are −4.939, −5.038, and −2.591, −3.366 respectively for TPP-2(FDI)-TPP and TPP-2(PMDI)-TPP. These results are found to be comparable with the UV–vis absorption studies indicating the synchronization of the calculated and experimental results. From the MEP analysis, we have found that the porphyrin acts as the nucleophilic center, whereas the polyimide moiety acts as the electrophilic center, indicating the easiest/possible transfer of electrons from porphyrin to 6FDA and PMDA. The intensity effect produced for TPP-2(FDI)-TPP and TPP-2(PMDI)-TPP showed a sublinear behavior and class 2 state. For TPP-2(FDI)-TPP the calculated J_sc was 4.09 mAcm⁻² and V_oc was 1.39V and for TPP-2(PMDI)-TPP, the value of J_sc and V_oc were found 4.5 mAcm⁻² and 1.77V respectively. The observed enhanced efficiency of 0.22% was calculated for TPP-2(FDI)-TPP which was due to the larger band gap and high LUMO level value.