Electrochemistry and spectroscopy of ortho-metalated complexes of Ir(III) and Rh(III)

Journal Article · Thu Feb 26 04:00:00 EST 1987 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100289a009· OSTI ID:7042280

Ohsawa, Y; Sprouse, S; King, K A; DeArmond, M K; Hanck, K W; Watts, R J

The electrochemical and UV-visible spectroscopic properties of Rh(III) and Ir(III) complexes of the ortho-metalating (NC) ligands, 2-phenylpyridine (ppy) and benzo(h)quinone (bzq), have been studied. Cyclic voltammetric studies of several of the dimeric species, (M(NC)/sub 2/Cl)/sub 2/, indicate metal-centered oxidation occurs at moderate potentials. Cationic monomers of the type M(NC)/sub 2/(NN)/sup +/ where (NN) = 2,2'-bipyridine or 1,10-phenanthroline have been prepared by reaction of the chelating ligands with the parent dimers. Cyclic voltammetric studies of these monomers indicate that several reversible ligand-centered reductions are generally observed and that the chelating ligand is more easily reduced than is the ortho-metalating ligand. Spectroscopic studies of the mixed ligand monomers indicate that dual emissions from MLCT states associated with the ortho-metalating and chelating ligands occur in the Ir(III) complexes whereas a single emission from a ligand-localized excited state is observed in the Rh(III) complexes. These results are discussed in terms of electronic and nuclear coupling factors analogous to those encountered in descriptions of bimolecular energy and electron-transfer processes.

• Research Organization: North Carolina State Univ., Raleigh
• OSTI ID: 7042280
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 91:5; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400400* -- Electrochemistry
AROMATICS
AZINES
BENZOQUINONES
CHEMICAL REACTIONS
CHEMISTRY
COMPLEXES
DATA
DIMERS
ELECTROCHEMISTRY
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
INFORMATION
IRIDIUM COMPLEXES
LIGANDS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PYRIDINES
QUINONES
REDUCTION
RHODIUM COMPLEXES
SPECTRA
TRANSITION ELEMENT COMPLEXES
ULTRAVIOLET SPECTRA
VISIBLE SPECTRA
VOLTAMETRY