Luminescent Carbonyl Hydrido Ruthenium(II) Diimine Coordination Compounds: Structural, Photophysical, and Electrochemical Properties

Abstract

A series of luminescent carbonyl hydrido ruthenium(II) complexes with various diimine ligands with diverse electronic properties, including Me2bpy (bpy = bipyridine), Me2phen (phen = phenanthroline), PhenCOOH, PhenCN, Me2Ph2phen, Ph2phen, and π‐conjugating dipyrido[3,2‐d:2′,3′‐f]quinoxaline (dpq), dipyrido[3,2‐a:2′,3′‐c](6,7,8,9‐tetrahydro)phenazine (dpqc), and dipyridophenazine (dppz) have been synthesized and characterized. Four of these complexes have been structurally characterized by X‐ray crystallography. The photophysical and electrochemical properties of these complexes have been studied. The effects of the electronic features and π‐conjugation of the diimine ligand on the electronic and photophysical properties of these complexes have also been discussed. Our study revealed that the luminescence performance of these complexes could be significantly enhanced by increasing the rigidity and π‐conjugation of the diimine ligand.

Synthesis and structural characterizations of three carbonyl(α-diimine)hydrido(triphenylphosphine)ruthenium(II) complexes with derivatives of 1,10-phenanthroline

“…A search of the Cambridge Structural Database (CSD, Version 5.45, updates of June 2024; Groom et al, 2016) for complexes with an Ru II metal coordinated by two triphenylphosphine ligands and one co-ligand coordinated via the N atoms of 1,10-phenanthroline and its derivatives revealed 20 structures with this system, including five with a central RuH + cation and one CO group [CSD refcodes IWELON, IWELUT, IWEMAA and OTUSIH (Yu et al, 2016), QUJCUU (Małecki et al, 2009) and OPANOL (Abbad et al, 2021)]. Additionally, four of these structures (IWELON, IWELUT, IWEMAA and OTUSIH) contain the PF 6 À counter-ion and molecules of various solvents.…”

The Tunable Luminescence of Ruthenium(II) Complexes Containing Different Tetrazolate Ligands

“…Herein, we intend to study the chemistry of ruthenium(II) complexes containing the ligands 2‐(1 H ‐tetrazol‐5‐yl)pyridine ( L 1 ), 4‐phenyl‐2‐(1 H ‐tetrazol‐5‐yl)pyridine ( L 2 ), and 2,4‐bis(1 H ‐tetrazol‐5‐yl)pyridine ( L 3 ), as a continuation of our recent reports on the luminescent Ru II complexes . Three luminescent Ru II compounds, [Ru II (bpy) 2 ( L 1 )](BF 4 ) ( 1 ), [Ru II (bpy) 2 ( L 2 )](BF 4 ) ( 2 ) and neutral compound [Ru II (bpy) 2 ( L 3 )] ( 3 ), were obtained by ligand‐substitution with these tz ligands (Figure ).…”

“…One of most attractive features for this family of Ru II compounds is that their redox properties as well as the ground‐state/excited state properties could be readily tunable, since their properties are very sensitive to the subtle alteration of the coordination environment around the central ruthenium atom. For examples, we have recently prepared a series of luminescent carbonyl hydrido Ru II diimine complexes with general formula [Ru II (N^N)(CO)(H)(PPh 3 ) 2 ](PF 6 ) (N^N = different types of diimine ligands) and it is found that the luminescence of these complexes could be gradually enhanced by increasing the rigidity and π‐conjugation of the diimine ligand . We have also designed two luminescent bis(bipyridyl)ruthenium(II) complexes bearing an ortho ‐hydroxy‐substituted bipyridine (bpyOH) or phenanthroline (phenOH) ligand, which could serve as phosphorescent pH probes due to the protonation/ deprotonation of a ‐OH groups in the ancillary bpyOH/PhenOH ligands …”

“…For examples, we have recently prepared a series of luminescent carbonyl hydrido Ru II diimine complexes with general formula [Ru II (N ∧ N)(CO)(H)(PPh 3 ) 2 ](PF 6 ) (N ∧ N = different types of diimine ligands) and it is found that the luminescence of these complexes could be gradually enhanced by increasing the rigidity and π-conjugation of the diimine ligand. [7] We have also designed two luminescent bis(bipyridyl)ruthenium(II) complexes bearing an ortho-hydroxy-substituted bipyridine (bpyOH) or phenanthroline (phenOH) ligand, which could serve as phosphorescent pH probes due to the protonation/ deprotonation of a-OH groups in the ancillary bpyOH/ PhenOH ligands. [8] phy and it clearly shows that the Ru II ion is octahedrally coordinated by two bpy ligands and a deprotonated L 3 ligand.…”

Effect of Coordination Modes on the Tunable Luminescence of 1,10‐Phenanthroline‐Based Complexes

“…Moreover, its quantum yield (19.4%) is also obviously higher than that of [Ru( phen )(PPh 3 )(CN) 3 ] − . We reported recently a variety of luminescent carbonylhydrido Ru(II) complexes [Ru(N^N)(CO)(H)(PPh 3 ) 2 ] + , whose luminescent properties are remarkably enhanced by extending the π‐system on the diimine ligands …”