Metal-to-ligand charge-transfer (MLCT) photochemistry: experimental evidence for the participation of a higher lying MLCT state in polypyridyl complexes of ruthenium(II) and osmium(II)

1990 ◽  
Vol 94 (1) ◽  
pp. 239-243 ◽  
Author(s):  
Richard S. Lumpkin ◽  
Edward M. Kober ◽  
Laura A. Worl ◽  
Zakir. Murtaza ◽  
Thomas J. Meyer
Inorganics ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 16 ◽  
Author(s):  
Jianfang Wu ◽  
Marc Alías ◽  
Coen de Graaf

A computational study is presented in which two strategies of ligand modifications have been explored to invert the relative energy of the metal-to-ligand charge transfer (MLCT) and metal-centered (MC) state in Fe(II)-polypyridyl complexes. Replacing the bipyridines by stronger σ donors increases the ligand-field strength and pushes the MC state to higher energy, while the use of ligands with a larger π conjugation leads to lower MLCT energies.


2017 ◽  
Vol 41 (2) ◽  
pp. 452-456 ◽  
Author(s):  
Nirmal K. Shee ◽  
Michael G. B. Drew ◽  
Dipankar Datta

Using 5,6-dihydro-5,6-epoxy-1,10-phenanthroline as the ligand L, the X-ray crystal structure of [FeL3](ClO4)2·2H2O is determined.


2005 ◽  
Vol 70 (11) ◽  
pp. 1891-1908 ◽  
Author(s):  
František Hartl ◽  
Sandrine Vernier ◽  
Peter Belser

Redox-controlled luminescence quenching is presented for a new Ru(II)-bipyridine complex [Ru(bpy)2(1)]2+ where ligand 1 is an anthra[1,10]phenanthrolinequinone. The complex emits from a short-lived metal-to-ligand charge transfer, 3MLCT state (τ = 5.5 ns in deaerated acetonitrile) with a low luminescence quantum yield (5 × 10-4). The emission intensity becomes significantly enhanced when the switchable anthraquinone unit is reduced to corresponding hydroquinone. On the contrary, chemical one-electron reduction of the anthraquinone moiety to semiquinone in aprotic tetrahydrofuran results in total quenching of the emission.


2016 ◽  
Vol 40 (6) ◽  
pp. 5002-5009 ◽  
Author(s):  
Nirmal K. Shee ◽  
Michael G. B. Drew ◽  
Dipankar Datta

A small difference in the conformation of an ancillary ligand L determines the lowest excited state in [Ru(bpy)2L]2+ and [Ru(phen)2L]2+.


2010 ◽  
Vol 49 (20) ◽  
pp. 9095-9097 ◽  
Author(s):  
Onduru S. Odongo ◽  
Marco M. Allard ◽  
H. Bernhard Schlegel ◽  
John F. Endicott

2020 ◽  
Author(s):  
Matthew Stout ◽  
Brian Skelton ◽  
Alexandre N. Sobolev ◽  
Paolo Raiteri ◽  
Massimiliano Massi ◽  
...  

<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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