Synthesis and photophysical properties of iridium(III) complexes with n-heterocyclic carbene ligands for light emitting diode application

This research aimed to synthesise iridium(III) complexes with N-heterocyclic carbene (NHC) ligands and investigate their photophysical properties. Complexes ofchlorobis(2,4-difluorophenylpyridine)(pyridyltriazole)iridium(III) (C1), bis(2,4-difluorophenylpyridine)(4-methylbenzylpyridyltr...

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Main Author: Nurul Husna As Saedah Bain
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Published: 2020
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Nurul Husna As Saedah Bain
Synthesis and photophysical properties of iridium(III) complexes with n-heterocyclic carbene ligands for light emitting diode application
description This research aimed to synthesise iridium(III) complexes with N-heterocyclic carbene (NHC) ligands and investigate their photophysical properties. Complexes ofchlorobis(2,4-difluorophenylpyridine)(pyridyltriazole)iridium(III) (C1), bis(2,4-difluorophenylpyridine)(4-methylbenzylpyridyltriazole)iridium(III) ion (C2),bis(2,4-difluorophenylpyridine)(hexylpyridyltriazole)iridium(III) ion (C3) andbis(2,4-difluorophenylpyridine)(2,6-difluorobenzylpyridyltriazole)iridium(III) ion (C4) were synthesised by reaction between dichloro-bridged iridium(III) dimer,[Ir(2,4-F2ppy)2(-Cl)]2 and corresponding triazolium salts. Iridium(III) complexes werecharacterised by Carbon, Hydrogen, Nitrogen and Sulphur (CHNS) elemental analyser andspectroscopic techniques: H and C Nuclear Magnetic Resonance (NMR), FourierTransform-Infrared (FTIR) and Liquid Chromatography-Mass Spectrometry (LCMS). The molecularstructure of C1 was determined by single crystal X-Ray Diffraction (XRD) technique. The photophysical study was performed using spectroscopic techniques: Ultraviolet-Visible(UV-Vis) and fluorescence. The results of the IR spectra showed strong frequency bands in the at15951400 cm? were due to(C=N) and (C=C). The H NMR spectra displayed the proton signals of phenylpyridine and pyridinetriazole in the aromatic region between 5.00 and10.00 ppm. The C NMR spectra showed aromatic carbon signals in the range 80150 ppmand 050 ppm for aliphatic carbon that matches with the corresponding number ofcarbon atoms in C1C4. Complexes of C1, C2, C3 and C4 exhibited ESI spectra at m/z 754.22,823.17, 803.11 and 847.15, respectively. X-Ray crystallographic study confirmed iridium(III)ion in C1 was coordinated to one pyridine-triazole, one chloro and two difluorophenylpyridineligands in a distorted octahedral geometry. Steady- state emission spectroscopy demonstratedC1, C2, C3 and C4 emitted blue-green light in dichloromethane solution with an emission maximum at472 nm, 452 nm, 471 nm and 470 nm, respectively. In conclusion, electronic properties ofiridium(III) complexes with NHC ligands have tuned the lowest-unoccupied molecular orbital (LUMO)energy to the blue region. The implication of this study is these iridium(III) complexes can bestudied as an alternative material to enhance luminescence efficiency of organic light-emitting diode (OLED).
format thesis
qualification_name
qualification_level Master's degree
author Nurul Husna As Saedah Bain
author_facet Nurul Husna As Saedah Bain
author_sort Nurul Husna As Saedah Bain
title Synthesis and photophysical properties of iridium(III) complexes with n-heterocyclic carbene ligands for light emitting diode application
title_short Synthesis and photophysical properties of iridium(III) complexes with n-heterocyclic carbene ligands for light emitting diode application
title_full Synthesis and photophysical properties of iridium(III) complexes with n-heterocyclic carbene ligands for light emitting diode application
title_fullStr Synthesis and photophysical properties of iridium(III) complexes with n-heterocyclic carbene ligands for light emitting diode application
title_full_unstemmed Synthesis and photophysical properties of iridium(III) complexes with n-heterocyclic carbene ligands for light emitting diode application
title_sort synthesis and photophysical properties of iridium(iii) complexes with n-heterocyclic carbene ligands for light emitting diode application
granting_institution Universiti Pendidikan Sultan Idris
granting_department Fakulti Sains dan Matematik
publishDate 2020
url https://ir.upsi.edu.my/detailsg.php?det=6802
_version_ 1747833312824524800
spelling oai:ir.upsi.edu.my:68022022-02-22 Synthesis and photophysical properties of iridium(III) complexes with n-heterocyclic carbene ligands for light emitting diode application 2020 Nurul Husna As Saedah Bain This research aimed to synthesise iridium(III) complexes with N-heterocyclic carbene (NHC) ligands and investigate their photophysical properties. Complexes ofchlorobis(2,4-difluorophenylpyridine)(pyridyltriazole)iridium(III) (C1), bis(2,4-difluorophenylpyridine)(4-methylbenzylpyridyltriazole)iridium(III) ion (C2),bis(2,4-difluorophenylpyridine)(hexylpyridyltriazole)iridium(III) ion (C3) andbis(2,4-difluorophenylpyridine)(2,6-difluorobenzylpyridyltriazole)iridium(III) ion (C4) were synthesised by reaction between dichloro-bridged iridium(III) dimer,[Ir(2,4-F2ppy)2(-Cl)]2 and corresponding triazolium salts. Iridium(III) complexes werecharacterised by Carbon, Hydrogen, Nitrogen and Sulphur (CHNS) elemental analyser andspectroscopic techniques: H and C Nuclear Magnetic Resonance (NMR), FourierTransform-Infrared (FTIR) and Liquid Chromatography-Mass Spectrometry (LCMS). The molecularstructure of C1 was determined by single crystal X-Ray Diffraction (XRD) technique. The photophysical study was performed using spectroscopic techniques: Ultraviolet-Visible(UV-Vis) and fluorescence. The results of the IR spectra showed strong frequency bands in the at15951400 cm? were due to(C=N) and (C=C). The H NMR spectra displayed the proton signals of phenylpyridine and pyridinetriazole in the aromatic region between 5.00 and10.00 ppm. The C NMR spectra showed aromatic carbon signals in the range 80150 ppmand 050 ppm for aliphatic carbon that matches with the corresponding number ofcarbon atoms in C1C4. Complexes of C1, C2, C3 and C4 exhibited ESI spectra at m/z 754.22,823.17, 803.11 and 847.15, respectively. X-Ray crystallographic study confirmed iridium(III)ion in C1 was coordinated to one pyridine-triazole, one chloro and two difluorophenylpyridineligands in a distorted octahedral geometry. Steady- state emission spectroscopy demonstratedC1, C2, C3 and C4 emitted blue-green light in dichloromethane solution with an emission maximum at472 nm, 452 nm, 471 nm and 470 nm, respectively. In conclusion, electronic properties ofiridium(III) complexes with NHC ligands have tuned the lowest-unoccupied molecular orbital (LUMO)energy to the blue region. The implication of this study is these iridium(III) complexes can bestudied as an alternative material to enhance luminescence efficiency of organic light-emitting diode (OLED). 2020 thesis https://ir.upsi.edu.my/detailsg.php?det=6802 https://ir.upsi.edu.my/detailsg.php?det=6802 text eng closedAccess Masters Universiti Pendidikan Sultan Idris Fakulti Sains dan Matematik Adachi, C., Baldo, M. A., Forrest, S. R., Lamansky, S., Thompson, M. E., & Kwong, R.High-Efficiency Red Electrophosphorescence Devices. Applied Physics Letters, 78(11), 16221624.https://doi.org/10.1063/1.1355007Ahn, S. Y., Lee, H. S., & Ha, Y. (2011). New Blue Phosphorescent Iridium Complexes ContainingPhenylpyridine And Triazole Ligands: Synthesis And Luminescence Studies. Journal of Nanoscience and Nanotechnology, 11(5), 44144418. https://doi.org/10.1166/jnn.2011.3656Ali, N. M., Macleod, V. L., Jennison, P., Sazanovich, I. V., Hunter, C., Weinstein, J. A., & Ward,M. D. (2012). 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