Authors: Adewale O. Adeloye | Simplice Koudjina | Vipin Kumar | Kgaugelo C. Tapala | Joachim Gbénou | Prabhakar Chetti
Source: Dyes and Pigments (article, 2025-01-04)
Field: Materials Science — Materials Chemistry

One-pot synthesis, photophysical, electrochemical and molecular property of mixed-ligands ruthenium complex functionalities: Potential materials for dye-sensitized solar cells (DSSCs) In our search for excellent photoactive materials for optolectronic applications such as dye-sensitized solar cells, four highly emissive, new fluorescent ruthenium coordinated dye complexes ( A-D ) having pyridyl-3,5-dicarboxylic acid and triphenylphosphine as the two common monodentate ligands formulated as RuCl 2 (PPh 3 ) 2 (dca) 2 , RuCl 2 (PPh 3 )Bpy(dca), RuCl 2 (PPh 3 )Hbpy(dca) and RuCl 2 (PPh 3 )Phen(dca) were prepared in a one-pot synthetic method, purified and characterized by IR, UV-Vis, PL, 1 H, 13 C, 31 P- NMR spectroscopy, elemental analysis electrochemistry and mass spectrometry. The UV-Vis absorption spectra revealed three to four well-define absorption peaks in the region 265–560 nm which were assigned to the π–π* transitions, two ligand-to-ligand charge-transfer (LLCT) bands and dπ(Ru)–π*(L) transitions respectively. High intensity and broad emissive photoluminescent properties in the mid-infrared region (> 640 nm) were recorded for all complexes. The electron-donating and/or electron-withdrawing ability of the carboxylic acid and chloride groups present in the complexes possibly favoured a one-electron oxidation reaction, stability of Ru 3+ /Ru 2+ redox properties and the potential of their applications in dye-sensitized solar cells and/or optoelectronics. The calculated results suggest that the frontiers Molecular Orbitals (FMOs), open-circuit voltage ( ), light-harvesting efficiency ( ), driving force for electron injection ( ), dye driving force regeneration ( ), molecular electrostatic potential (MESP), and density of states ( ) are affected by substituents groups introduced in the ruthenium complex. The of all the dyes are theoretically calculated at J SC 9, 12, and 15 mA cm -2 to give the higher power conversion efficiency ( ) of the solar cell obtained for dye B at (9.36 %). The comparative investigation shows that extended π-spacer variation in the ligands is essential in the fine-tuning of the overall performance of the DSSCs in the ruthenium complexes. • Four highly emissive mixed-ligand ruthenium dyes ( A-D ) are synthesized and characterized. • The UV-Vis absorbing complex dyes ( A-D ) show high molar extinction coefficient and high emission intensity at the common far visible region wavelength of 650 nm. • The complex dyes exhibited a one-electron redox activity in the cyclic voltammogram. • The complex dye chemical structures and photophysical properties agreed perfectly well with the DFT/TD-DFT, DOS, and MEPs calculations. • Kinetic stability studies showed all complexes to be stable in DMSO solvent. • The η of the dyes theoretically calculated at J SC 9, 12, and 15 mA cm -2 gave the highest power conversion efficiency (η) of the solar cell for dye B at (9.36%). Ruthenium ; Dye-sensitized solar cell ; Electrochemistry ; Chemistry ; Combinatorial chemistry ; Photochemistry ; Materials science ; Organic chemistry ; Catalysis ; Electrode ; Physical chemistry Polyoxometalates: Synthesis and Applications ; Advanced Nanomaterials in Catalysis ; Radioactive element chemistry and processing