[Ir(N^N^N)(C^N)L]<sup>+</sup>: A New Family of Luminophores Combining Tunability and Enhanced Photostability
作者:Danielle N. Chirdon、Wesley J. Transue、Husain N. Kagalwala、Aman Kaur、Andrew B. Maurer、Tomislav Pintauer、Stefan Bernhard
DOI:10.1021/ic402411g
日期:2014.2.3
The relatively unexplored luminophore architecture [Ir(N boolean AND N boolean AND N)(C boolean AND N)L](+) (N boolean AND N boolean AND N = tridentate polypyridyl ligand, C<^>N = 2-phenylpyridine derivative, and L = monodentate anionic ligand) offers the stability of tridentate polypyridyl coordination along with the tunability of three independently variable ligands. Here, a new family of these luminophores has been prepared based on the previously reported compound [Ir(tpy)(ppy)Cl](+) (tpy = 2,2':6',2 ''-terpyridine and ppy = 2-phenylpyridine). Complexes are obtained as single stereoisomers, and ligand geometry is unambiguously assigned via X-ray crystallography. Electrochemical analysis of the materials reveals facile HOMO modulation through ppy functionalization and alteration of the monodentate ligand's field strength. Emission reflects similar modulation shifting from orange to greenish-blue upon replacement of chloride with cyanide. Many of the new compounds exhibit impressive room temperature phosphorescence with lifetimes near 3 mu s and quantum yields reaching 28.6%. Application of the new luminophores as photosensitizers for photocatalytic hydrogen generation reveals that their photostability in coordinating solvent is enhanced as compared to popular [Ir(ppy)(2)(bpy)](+) (bpy = 2,2'-bipyridine) photosensitizers. Yet, the binding of their monodentate ligand emerges as a source of instability during the redox processes of cyclic voltammetry and mass spectrometry. DFT modeling of electronic structure is provided for all compounds to elucidate experimental properties.
A Lanthanide-Complex-Based Ratiometric Luminescent Probe Specific for Peroxynitrite
long luminescence lifetimes of 1.38 and 0.26 ms, respectively. It was found that the luminescence of [Tb3+(DTTA)] could be quenched by ONOO− rapidly and specifically in aqueous buffers, while that of [Eu3+(DTTA)] did not respond to the addition of ONOO−. Thus, by simply mixing [Eu3+(DTTA)] and [Tb3+(DTTA)] in an aqueous buffer, a ratiometricluminescenceprobe specific for time‐gatedluminescence detection
Fine-Tuning Metal and Ligand-Centered Redox Potentials of Homoleptic Bis-Terpyridine Complexes with 4′-Aryl Substituents
作者:John C. Dickenson、MacKenzie E. Haley、Jacob T. Hyde、Zachary M. Reid、Travis J. Tarring、Diana A. Iovan、Daniel P. Harrison
DOI:10.1021/acs.inorgchem.1c01233
日期:2021.7.5
(terpy) and substituted derivatives of the form [M(R-terpy)2]2+ display a wide range of redox potentials that correlate well to the Hammett parameter of the terpy substituents. Less is known about the impact of incorporating a phenyl spacer between the functional group responsible for controlling the electron density of terpy and how that translates to metal complexes of the form [M(4′-aryl-terpy)2]2+, where