121st General Meeting of the KCS

Type Poster Presentation
Area Inorganic Chemistry
Room No. Event Hall
Time 4월 19일 (목요일) 11:00~12:30
Code INOR.P-22
Subject Solvatochromic and Dual Emissive Properties of Phosphorescent Iridium(III) Cyclometalates Bearing Tethered ortho-Carborane
Authors Young Hoon Lee, Heechai Lee1, Juhee Kim1, Min Hyung Lee1,*
Department of Chemistry and EHSRC, University of Ulsan, Korea
1Department of Chemistry, University of Ulsan, Korea
Abstract Two alkylene-tethered [R-(CBdfppy)2IrX] complexes (R = 1,6-hexanediyl, CB = o-carboran-1-yl; dfppy = 2-(2,4-difluorophenyl)-pyridinato-C2,N; X = picolinate (pic) (1) and acetylacetonate (acac) (2)) with 2-R-substituted o-carboranes at the 5-position in the phenyl ring of the dfppy ligand were prepared and characterized by X-ray diffraction studies and spectroscopic analyses. Resulting from the crystal structure of both complexes, carboranyl C­­­­­­‒C bond distances is comparable to that of the corresponding unlinked complexes and torsion angles between difluorophenyl and carboranyl C‒C bonds reflected the existence of π(dfppy)-σ*(C‒C) interactions. The phosphorescence efficiency of alkylene-linked complexes was higher than those of the unlinked compounds, indicative of restricted carborane rotation by alkylene chain. In addition, the efficiency varied from highly blue emissive (ΦPL= 0.92 (1) and 0.87 (2) in toluene) to poorly red emissive (ΦPL < 0.01 in DMF) depending on the dielectric constant of solvents. Interestingly, the compound 1 exhibited white emission in 1,2-dichloroethane by dual emission in the high and low energy regions, respectively derived from solvatochromism.
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