Theoretical Studies of the Electronic Structure and Spectroscopic Properties of [Ru(Htcterpy)(NCS)₃]^3–

Abstract

The ground-and excited-state structures of [Ru(Htcterpy)-(NCS) 3 ] 3-(1H) (tcterpy = 4,4Ј,4ЈЈ-tricarboxy-2,2Ј:6Ј,2ЈЈ-terpyridine) are optimized by the DFT and CIS methods, respectively. Absorption and emission spectra in the gas phase and in solution (ethanol and water) are predicted at the TD-DFT/ B3LYP level. Experimental spectra are roughly reproduced by our calculated results. In ethanol solution, the HOMOs of the absorption spectra are dominated by d orbitals of the ruthenium atom and thiocyanate ligands, and the LUMOs possess π*(tcterpy) character with considerable carboxyl contribution. In the theoretically simulated absorption spectra, the first four bands are attributed to Ru/NCSǞπ*(tcterpy) charge-transfer (MLCT/LLCT) transitions, whereas the fifth

Tuning the luminescence lifetimes of ruthenium(ii) polypyridine complexes and its application in luminescent oxygen sensing

“…20 Recently it was proposed that several transitions may be involved in the 1 MLCT absorption bands of Ru(II) complexes, such as dp(Ru) / p*(bpy) and dp(Ru) / p*(bpy(C^C-Ph)). 40,41 Our DFT/TDDFT calculations support this assignment (vide infra).…”

“…This assumption is consistent with a recent theoretical investigation on Ru(II) polypyridine complexes. 40,41,59 Complex 3 shows a long lifetime of 58.4 ms, indicating that the emissive state is not the typical 3 MLCT state. The transient absorption demonstrated that the long-lived excited state is pyrene-based, we propose that the excited triplet state is 3 IL/ 3 LLCT state (Scheme 3 and Table 3).…”

“…Theoretical calculations: assignment of the lowest-lying excited state of the complexes Theoretical calculations have been successfully used to reveal the photophysics of luminophores, [49][50][51][52][53][54] including Ru(II) polypyridine complexes. 35,40,41,49,52,[55][56][57][58] Herein we carried out preliminary theoretical calculations on the Ru complexes to study the photophysical properties, especially the lowest-lying singlet excited states and the triplet excited states. These excited states are closely related to the absorption and the emission properties of the Ru complexes.…”

High Molar Extinction Coefficient Ru(II)-Mixed Ligand Polypyridyl Complexes for Dye Sensitized Solar Cell Application

“…This could be probably due to more charge transfer to the LUMO orbitals for these dyes as compared to black dye. In the LUMO orbitals of these complexes, the electron density distributions mainly located on H 3 tctpy ligand, while for black dye it is only ascribed to the centre pyridine of H 3 tctpy [31]. As compared to the black dye-sensitized solar cell, the mLBD dyes showed higher current densities, which could be probably because of their increased incident photon to-current conversion efficiencies spectra.…”

Enhanced luminescence oxygen sensing property of Ru(II) bispyridine complexes by ligand modification

“…Recently density function theory (DFT) and time dependent DFT (TDDFT) calculations have been successfully used in the study of luminescent organic materials and transitional metal complexes [28][29][30][31]. The understanding of the photophysical properties can be improved with these calculations, especially the information of the low-lying excited states.…”