Influence of variations in the chromophoric ligand on the properties of metal-to-ligand charge-transfer excited states

Journal Article · Wed Sep 07 00:00:00 EDT 1988 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00291a031· OSTI ID:5762485

Johnson, S R; Westmoreland, T D; Caspar, J V; Barqawi, K R; Meyer, T J

The effects of variations in the chromophoric ligand on the properties of the metal-to-ligand charge-transfer (MLCT) excited states in the series (Os(PP)/sub 3/)/sup 2+/, ((PP)/sub 2/Os(py)/sub 2/)/sup 2+/, and ((PP)/sub 2/Os(LL))/sup 2+/ (PP = 2,2'-bipyridine, 1,10-phenanthroline, or a substituted derivative; py = pyridine; LL = das, dppm, dppb, dppene) have been investigated. From a series of electrochemical and photophysical measurements it has been determined that (1) substituent variations in the chromophoric ligands have a relatively minor effect on the d/pi/(Os) levels as evidenced by variations in E/sub 1/2/ values for the ground-state Os(III/II) couples, (2) linear correlations exist between metal-to-ligand charge-transfer (MLCT) absorption or emission band energies and the difference in metal-based oxidation and ligand-based reduction potentials, E/sub 1/2/(Os/sup III/II/) - E/sub 1/2/(PP/sup 0//minus//), and (3) a linear relationship between 1n k/sub nr/ and the emission energy, E/sub em/, exists, consistent with the energy gap law. It appears that for nonradiative decay both the pattern of acceptor vibrations and the vibrationally induced electronic coupling term remain relatively constant as the chromophoric ligand is varied. 26 references, 4 figures, 2 tables.

• Research Organization: Univ. of North Carolina, Chapel Hill (USA)
• DOE Contract Number: FG05-86ER13633
• OSTI ID: 5762485
• Journal Information: Inorg. Chem.; (United States), Vol. 27:18
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
BIPYRIDINES
EXCITED STATES
ORGANIC PHOSPHORUS COMPOUNDS
OSMIUM COMPLEXES
PHENANTHROLINES
PYRIDINES
EXPERIMENTAL DATA
AROMATICS
AZAARENES
AZINES
COMPLEXES
DATA
ENERGY LEVELS
HETEROCYCLIC COMPOUNDS
INFORMATION
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
TRANSITION ELEMENT COMPLEXES
400201* - Chemical & Physicochemical Properties