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Title: Photoinduced energy transfer in transition metal complex oligomers

The work we have done over the past three years has been directed toward the preparation, characterization and photophysical examination of mono- and bimetallic diimine complexes. The work is part of a broader project directed toward the development of stable, efficient, light harvesting arrays of transition metal complex chromophores. One focus has been the synthesis of rigid bis-bidentate and bis-tridentate bridging ligands. We have managed to make the ligand bphb in multigram quantities from inexpensive starting materials. The synthetic approach used has allowed us prepare a variety of other ligands which may have unique applications (vide infra). We have prepared, characterized and examined the photophysical behavior of Ru(II) and Re(I) complexes of the ligands. Energy donor/acceptor complexes of bphb have been prepared which exhibit nearly activationless energy transfer. Complexes of Ru(II) and Re(I) have also been prepared with other polyunsaturated ligands in which two different long lived ( > 50 ns) excited states exist; results of luminescence and transient absorbance measurements suggest the two states are metal-to-ligand charge transfer and ligand localized {pi}{r_arrow}{pi}* triplets. Finally, we have developed methods to prepare polymetallic complexes which are covalently bound to various surfaces. The long term objective of this work is to makemore » light harvesting arrays for the sensitization of large band gap semiconductors. Details of this work are provided in the body of the report.« less
Publication Date:
OSTI Identifier:
464184
Report Number(s):
DOE/ER/14309-T1
ON: DE97005234; TRN: 97:002689
DOE Contract Number:
FG05-92ER14309
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: [1997]
Research Org:
Tulane Univ., New Orleans, LA (United States)
Sponsoring Org:
USDOE Office of Energy Research, Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
40 CHEMISTRY; RUTHENIUM COMPLEXES; ENERGY TRANSFER; LUMINESCENCE; RHENIUM COMPLEXES; LIGANDS; BIPYRIDINES; SPECTROSCOPY; PHOSPHONATES; PHOSPHONIC ACIDS; DISSOCIATION; EXCITED STATES; MOLECULAR STRUCTURE; STRUCTURAL MODELS; PHOTOCHEMICAL REACTIONS