title: Luminescent Metal Complexes Featuring Photophysically Innocent Boron Cluster Ligands.
abstract: We report the synthesis and characterization of a series of d8metal complexes featuring robust and photophysically innocent strong-field chelating 1,1'-bis(o-carborane) (bc) ligand frameworks. A combination of UV-Vis spectroscopy, single crystal X-ray structural analysis, and DFT calculations of these species suggest that the dianionicbcligand does not contribute to any visible metal-to-ligand charge transfer (MLCT) transitions, yet it provides a strong ligand field in these complexes. Furthermore, abc-based Pt(II) complex containing a 4,4'-di-tert-butyl-2,2'-bipyridine ligand (dtb-bpy) has been prepared and was found to display blue phosphorescent emission dominated by MLCT from the Pt(II) center to the dtb-bpy ligand. Importantly, the bulky three-dimensional nature of thebcligand precludes intermolecular Pt(II)⋯Pt(II) interactions in the solid state where the resulting compounds retain their emission properties. This study opens a potentially new avenue for designing organic light-emitting diode (OLED) materials with tunable properties featuring photophysically innocent boron-rich cluster ligands.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90025-1569, USA.
authors.forename: Kent O
authors.initials: KO
authors.lastname: Kirlikovali
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90025-1569, USA.
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Axtell
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90025-1569, USA.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Gonzalez
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90025-1569, USA.
authors.forename: Alice C
authors.initials: AC
authors.lastname: Phung
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90025-1569, USA.
authors.forename: Saeed I
authors.initials: SI
authors.lastname: Khan
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90025-1569, USA.
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Spokoyny