Site‐selective and Stark spectroscopy of the series [Os(2,2’‐bipyridine)3−x(2,2’‐bipyridine‐d8)x]2+ (x=0–3) in single‐crystal [Ru(2,2’‐bipyridine)3](PF6)2. Localization of an intramolecular triplet metal‐to‐ligand charge transfer exciton by partial deuteration

1995 ◽  
Vol 102 (12) ◽  
pp. 4823-4831 ◽  
Author(s):  
Hans Riesen ◽  
Lynne Wallace ◽  
Elmars Krausz
Keyword(s):  
Charge Transfer ◽  
Single Crystal ◽  
Stark Spectroscopy ◽  
Ligand Charge Transfer ◽  
Site Selective

scholarly journals Tuning π-Acceptor/σ-Donor Ratio of the 2-Isocyanoazulene Ligand: Non-Fluorinated Rival of Pentafluorophenyl Isocyanide and Trifluorovinyl Isocyanide Discovered

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 981
Author(s):  
Mason D. Hart ◽  
John J. Meyers ◽  
Zachary A. Wood ◽  
Toshinori Nakakita ◽  
Jason C. Applegate ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Coordination Chemistry ◽  
Single Crystal ◽  
13C Nmr ◽  
Quantitative Assessment ◽  
X Ray ◽  
New Class ◽  
Linear Relationships ◽  
Ligand Charge Transfer ◽  
Donor Characteristics

Isocyanoazulenes (CNAz) constitute a relatively new class of isocyanoarenes that offers rich structural and electronic diversification of the organic isocyanide ligand platform. This article considers a series of 2-isocyano-1,3-X2-azulene ligands (X = H, Me, CO2Et, Br, and CN) and the corresponding zero-valent complexes thereof, [(OC)5Cr(2-isocyano-1,3-X2-azulene)]. Air- and thermally stable, X-ray structurally characterized 2-isocyano-1,3-dimethylazulene may be viewed as a non-benzenoid aromatic congener of 2,6-dimethyphenyl isocyanide (2,6-xylyl isocyanide), a longtime “workhorse” aryl isocyanide ligand in coordination chemistry. Single crystal X-ray crystallographic {Cr–CNAz bond distances}, cyclic voltametric {E1/2(Cr0/1+)}, 13C NMR {δ(13CN), δ(13CO)}, UV-vis {dπ(Cr) → pπ*(CNAz) Metal-to-Ligand Charge Transfer}, and FTIR {νN≡C, νC≡O, kC≡O} analyses of the [(OC)5Cr(2-isocyano-1,3-X2-azulene)] complexes provided a multifaceted, quantitative assessment of the π-acceptor/σ-donor characteristics of the above five 2-isocyanoazulenes. In particular, the following inverse linear relationships were documented: δ(13COtrans) vs. δ(13CN), δ(13COcis) vs. δ(13CN), and δ(13COtrans) vs. kC≡O,trans force constant. Remarkably, the net electron withdrawing capability of the 2-isocyano-1,3-dicyanoazulene ligand rivals those of perfluorinated isocyanides CNC6F5 and CNC2F3.

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>

Synthesis, Characterization and Photophysical Properties of Rhenium(I) Complexes Containing 4,5-Diazafluorene Ligan

2011 ◽  
Vol 239-242 ◽  
pp. 2612-2615
Author(s):  
Jie Xiu Wang ◽  
Feng Zhao
Keyword(s):  
Charge Transfer ◽  
Fluorescence Spectra ◽  
Photophysical Properties ◽  
Absorption And Fluorescence Spectra ◽  
Rhenium Complexes ◽  
H Nmr ◽  
Ligand Charge Transfer

Two related tricarbonyl rhenium complexes with the formula of [Re(CO)3(L)Cl], where L=4,5-diazafluoren-9-one (Dafo-Re) and 9-(phenylamino)-4,5-diazafluoren (PADF-Re) were successfully synthesized with the aim to explore the effect of the geometry of Dafo on Rhenium(I) coordination, and characterized by1H NMR. Photophysical behaviors are investigated by UV–vis absorption and Fluorescence spectra. The two complexes Dafo-Re and PADF-Re show metal-to-ligand charge transfer absorptions at ca.391nm, ca.394 nm and emissions at ca.492nm, ca.470nm, respectively.

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