Luminescent metal complexes featuring photophysically innocent boron cluster ligands† †Electronic supplementary information (ESI) available: See ESI for full experimental details. CCDC 1446940–1446945. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c6sc01146b

• Published in: Chemical science (Cambridge) 2016-04, Vol.7 (8), p.5132-5138
• Main Authors: Kirlikovali, Kent O., Axtell, Jonathan C., Gonzalez, Alejandra, Phung, Alice C., Khan, Saeed I., Spokoyny, Alexander M.
• Format: Article
• Language: English
• Subjects: Chemistry
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/c6sc01146b

We report the synthesis and characterization of a series of d 8 metal complexes featuring robust and photophysically innocent strong-field chelating 1,1′-bis( o -carborane) ( bc ) ligand frameworks. We report the synthesis and characterization of a series of d 8 metal 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 dianionic bc ligand does not contribute to any visible metal-to-ligand charge transfer (MLCT) transitions, yet it provides a strong ligand field in these complexes. Furthermore, a bc -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 the bc ligand 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.