We describe the synthesis and crystal structures of four iridium compounds containing the 2-(4,6-difluorophenyl)pyridyl ligand. Cleavage of dichloro-bridged iridium(III) dimers with phosphorus ligands leads to (46dfppy)2Ir(L)(Cl) where L = PPh3 or P(OPh)3. Treatment of the chloro compounds with cyanide forms the cyano complexes (46dfppy)2Ir(L)(CN). All complexes exhibit a trans effect in their molecular structures due to the phosphorus ligands, with the phosphite having a greater effect than the phosphine. With L = PPh3, blue photoluminescence with CIE coordinates (x = 0.16, y = 0.24), quantum yield of 0.66 ± 0.15 and 4.5 ± 0.5 μs decay time is measured. For L = P(OPh)3, blue photoluminescence with CIE coordinates (x = 0.16, y = 0.21), quantum yield of 0.65 ± 0.15 and 2.9 ± 0.3 μs decay time is measured.
Bibliographical noteFunding Information:
We thank the X-Ray Crystallographic Laboratory, LeClaire-Dow Instrumentation Facility, Department of Chemistry, University of Minnesota for its contribution. The authors would like to acknowledge Ms. Laura Clouston and the CHEM5755 X-Ray Crystallography for the assistance in collecting single crystal diffraction data on sample 1 . The Bruker-AXS D8 Venture diffractometer was purchased through a grant from NSF/MRI (# 1229400 ) and the University of Minnesota . We appreciate the help from Alexander Drobshoff in acquiring the phosphorescence lifetimes, and the use of a CIE calculator, written by Stephen A. Payne. This work was funded by the National Nuclear Security Administration, Defense Nuclear Nonproliferation Research and Development Office of the U.S. Department of Energy under Contract DE-AC03-76SF00098, and was performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Release number is LLNL-JRNL-669760.
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- Blue phosphorescence
- Iridium complexes
- Metallorganic light emitters