Orbital Analysis of Metal-to-Ligand Charge Transfer and Oxidation in (NH3)5RuL2+Complexes:  Effective t2gOrbital Ordering and the Role of Ligand π and π* Orbitals

1996 ◽  
Vol 100 (4) ◽  
pp. 1104-1110 ◽  
Author(s):  
Yeung-gyo K. Shin ◽  
Bruce S. Brunschwig ◽  
Carol Creutz ◽  
Marshall D. Newton ◽  
Norman Sutin
Keyword(s):  
Charge Transfer ◽  
Ligand Charge Transfer ◽  
Orbital Analysis

Role of Ruthenium Oxidation States in Ligand-to-Ligand Charge Transfer Processes

2012 ◽  
Vol 51 (3) ◽  
pp. 1261-1268 ◽  
Author(s):  
Cristina L. Ramírez ◽  
César N. Pegoraro ◽  
Oscar Filevich ◽  
Andrea Bruttomeso ◽  
Roberto Etchenique ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Oxidation States ◽  
Transfer Processes ◽  
Ligand Charge Transfer ◽  
Ruthenium Oxidation

[Ru(bpy)3]2+* and other remarkable metal-to-ligand charge transfer (MLCT) excited states

2013 ◽  
Vol 85 (7) ◽  
pp. 1257-1305 ◽  
Author(s):  
David W. Thompson ◽  
Akitaka Ito ◽  
Thomas J. Meyer
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Energy Gap ◽  
Hybrid Approach ◽  
Medium Effects ◽  
New Approach ◽  
Dye Sensitized ◽  
Ligand Charge Transfer ◽  
Energy Gap Law

In 1974, the metal-to-ligand charge transfer (MLCT) excited state, [Ru(bpy)3]2+*, was shown to undergo electron transfer quenching by methylviologen dication (MV2+), inspiring a new approach to artificial photosynthesis based on molecules, molecular-level phenomena, and a “modular approach”. In the intervening years, application of synthesis, excited-state measurements, and theory to [Ru(bpy)3]2+* and its relatives has had an outsized impact on photochemistry and photophysics. They have provided a basis for exploring the energy gap law for nonradiative decay and the role of molecular vibrations and solvent and medium effects on excited-state properties. Much has been learned about light absorption, excited-state electronic and molecular structure, and excited-state dynamics on timescales from femtoseconds to milliseconds. Excited-state properties and reactivity have been exploited in the investigation of electron and energy transfer in solution, in molecular assemblies, and in derivatized polymers and oligoprolines. An integrated, hybrid approach to solar fuels, based on dye-sensitized photoelectrosynthesis cells (DSPECs), has emerged and is being actively investigated.

scholarly journals Cytotoxicity of cyclometallated ruthenium complexes: the role of ligand exchange on the activity

2013 ◽  
Vol 371 (1995) ◽  
pp. 20120135 ◽  
Author(s):  
Alycia M. Palmer ◽  
Bruno Peña ◽  
R. Bryan Sears ◽  
Olivia Chen ◽  
Maya El Ojaimi ◽  
...  
Keyword(s):  
Cell Death ◽  
Photodynamic Therapy ◽  
Charge Transfer ◽  
Dna Binding ◽  
Coordination Sphere ◽  
Ligand Exchange ◽  
Ligand Substitution ◽  
Tissue Penetration ◽  
Ligand Charge Transfer

The cyclometallated Ru(II) complexes cis -[Ru(phpy)(phen)(CH 3 CN) 2 ](PF 6 ) ( 1 ; phpy − =deprotonated 2-phenylpyridine, phen=1,10-phenanthroline) and cis -[Ru(phpy)(bpy)(CH 3 CN) 2 ](PF 6 ) ( 2 ; bpy=2,2′-bipyridine) were investigated as potential agents for photodynamic therapy. The presence of phpy − in the coordination sphere results in a red-shift of the Ru→phen and Ru→bpy metal-to-ligand charge transfer of 1 and 2 , respectively, thus improving the tissue penetration of light while maintaining the efficient photo-induced ligand exchange required for DNA binding. The 14-fold enhancement of OVCAR-5 cell death that occurs upon irradiation with 690 nm light can be attributed to photo-aquation. The role of glutathione (GSH) on the toxicity of the complex was also explored. Complexes 1 and 2 undergo ligand substitution in the presence of GSH in the dark, such that the metal may covalently bind to biomolecules. The combination of photo-induced ligand exchange and GSH-facilitated ligand exchange may explain the observed cytotoxicity.

Dynamic adjustment of emission from both singlets and triplets: the role of excited state conformation relaxation and charge transfer in phenothiazine derivates

2021 ◽  
Author(s):  
Weidong Qiu ◽  
Xinyi Cai ◽  
Mengke Li ◽  
Liangying Wang ◽  
Yanmei He ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Dynamic Adjustment ◽  
Twisted Intramolecular Charge Transfer

Dynamic adjustment of emission behaviours by controlling the extent of twisted intramolecular charge transfer character in excited state.

Synthesis and Photochemical Properties of Re(I) Tricarbonyl Complexes Bound to Thione and Thiazole-2-ylidene Ligands

2020 ◽  
Author(s):  
Matthew Stout ◽  
Brian Skelton ◽  
Alexandre N. Sobolev ◽  
Paolo Raiteri ◽  
Massimiliano Massi ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Ligand Exchange ◽  
Ligand Substitution ◽  
Bidentate Ligand ◽  
The Other ◽  
Ligand Exchange Reaction ◽  
Multiple Products ◽  
Ligand Charge Transfer ◽  
Photochemical Properties

<p>Three Re(I) tricarbonyl complexes, with general formulation Re(N^L)(CO)<sub>3</sub>X (where N^L is a bidentate ligand containing a pyridine functionalized in the position 2 with a thione or a thiazol-2-ylidene group and X is either chloro or bromo) were synthesized and their reactivity explored in terms of solvent-dependent ligand substitution, both in the ground and excited states. When dissolved in acetonitrile, the complexes bound to the thione ligand underwent ligand exchange with the solvent resulting in the formation of Re(NCMe)<sub>2</sub>(CO)<sub>3</sub>X. The exchange was found to be reversible, and the starting complex was reformed upon removal of the solvent. On the other hand, the complexes appeared inert in dichloromethane or acetone. Conversely, the complex bound to the thiazole-2-ylidene ligand did not display any ligand exchange reaction in the dark, but underwent photoactivated ligand substitution when excited to its lowest metal-to-ligand charge transfer manifold. Photolysis of this complex in acetonitrile generated multiple products, including Re(I) tricarbonyl and dicarbonyl solvato-complexes as well as free thiazole-2-ylidene ligand.</p>

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