Research Information System
Journal of Molecular Structure, vol.1333, 2025 (SCI-Expanded, Scopus)
Two novel D-π-A-π-A types of metal-free organic dyes, QX-DMA and QX-TPA, were synthesized in good yields (88 % and 97 %, respectively). The skeletons of the dyes included 2,3-diphenylquinoxaline as an auxiliary acceptor incorporated in between two π-spacers of thiophene units. One thiophene ring is linked with cyanoacrylic acid as an anchoring electron acceptor, while the other one is connected to an electron donor of substituted aniline; N,N-dimethyaniline (DMA) and triphenylamine (TPA), respectively. An effective synthetic approach for the dyes' synthesis was studied. The chemical structures of the compounds were confirmed and characterized by different spectral data (FTIR, HRMS, and NMR). The QX-DMA and QX-TPA dyes showed ICT band in the visible region with a high molar extinction coefficient (λmax = 532 and 522 nm), (ε = 17,412 and 38,938 M−1 cm−1), respectively in THF solution. A hyperchromic shift in the absorption was revealed by QX-TPA dye due to the influence of the conjugation and the non-planar shape of TPA moiety. The cyclic voltammetry data indicated that the HOMO and LUMO energy levels for QX-DMA and QX-TPA dyes were found to be (-4.90, -2.74 eV) and (-5.18, -3.09 eV), respectively. Thus, the dyes accomplished the intended results, qualifying them for utilization in photovoltaic applications such as sensitizers in dye-sensitized solar cells (DSSCs). The DSSC efficiencies of 5.66, and 6.80 % have been achieved with the electrolyte containing I₂ (0.05 M), LiI (0.1 M), 1‑butyl‑3-methylimidazolium iodide (BMII, 0.6 M), 4‑tert-butylpyridine (TBP, 0.5 M), and acetonitrile for the QX-DMA and QX-TPA dyes, respectively.