TY - JOUR

T1 - Electronically exited states in triphenylphosphine complexes of Ruthenium (II): TD DFT study

AU - Krauklis, Irina V.

AU - Reshetova, Kristina I.

AU - Podkopaeva, Oksana Yu.

AU - Chizhov, Yuri V.

PY - 2018

Y1 - 2018

N2 - Singlet and triplet electronically exited states (EES) of the luminescent and photoactive complexes [Ru (bpy)2(PPh3) (L)]+2, where bpy is 2,20 - bipyridyl, L is 4-aminopyridine, pyridine (py), or 4,40 - bipyridyl (bipy) are studied within TDDFT/B3LYP/[6-31G(d) + LanL2DZ(Ru)] method in the energy region of 2.2 eV 4.5 eV. We revealed the nature of more than 70 EES and constructed a series of multi-level schemes of the EE states, taking into account 3 dd levels of Ru (II) and metal-to-ligand charge-transfer states of pyridine ligands (MLCT(L)). These schemes gave us the opportunity to evaluate the activation energy of 3 dd-states of Ru (II) ion and to explain the weak luminescence of triphenylphosphine complexes of Ruthenium (II) (TPRC) at room temperature. Besides, we discovered that the emission energy (Eem) of the principal luminescent transition 3 MLCT!1 GS of the complexes studied depends linearly on the effective charge on the nitrogen atom (Q(N4)) of the coordinated pyridyl ligand. The electronic absorption spectra of TPRC are calculated and interpreted within TD DFT, and the energy of luminescenttransition (ET-S) from the lowest triplet 3 MLCT to the ground state for all TPRC under study is evaluated. It is shown that the variation of pyridine ligands (L) from electron donors to electron acceptors results in the hypsochromic shift of ET-S, which is in good agreement with the experimental data.

AB - Singlet and triplet electronically exited states (EES) of the luminescent and photoactive complexes [Ru (bpy)2(PPh3) (L)]+2, where bpy is 2,20 - bipyridyl, L is 4-aminopyridine, pyridine (py), or 4,40 - bipyridyl (bipy) are studied within TDDFT/B3LYP/[6-31G(d) + LanL2DZ(Ru)] method in the energy region of 2.2 eV 4.5 eV. We revealed the nature of more than 70 EES and constructed a series of multi-level schemes of the EE states, taking into account 3 dd levels of Ru (II) and metal-to-ligand charge-transfer states of pyridine ligands (MLCT(L)). These schemes gave us the opportunity to evaluate the activation energy of 3 dd-states of Ru (II) ion and to explain the weak luminescence of triphenylphosphine complexes of Ruthenium (II) (TPRC) at room temperature. Besides, we discovered that the emission energy (Eem) of the principal luminescent transition 3 MLCT!1 GS of the complexes studied depends linearly on the effective charge on the nitrogen atom (Q(N4)) of the coordinated pyridyl ligand. The electronic absorption spectra of TPRC are calculated and interpreted within TD DFT, and the energy of luminescenttransition (ET-S) from the lowest triplet 3 MLCT to the ground state for all TPRC under study is evaluated. It is shown that the variation of pyridine ligands (L) from electron donors to electron acceptors results in the hypsochromic shift of ET-S, which is in good agreement with the experimental data.

KW - Photoactive triphenylphosphine Ruthenium(II) complexes

KW - Electronically exited states

KW - TDDFT

KW - Photoactive triphenylphosphine Ruthenium (II) complexes Electronically exited states TDDFT

M3 - Article

VL - 354

SP - 112

EP - 118

JO - Journal of Photochemistry and Photobiology A: Chemistry

JF - Journal of Photochemistry and Photobiology A: Chemistry

SN - 1010-6030

ER -