Abstract
A series of α-diimine ligands including alkyl-, bromo-, silyl- or silylethynyl-substituted 2,2′-bipyridines (bpy) for auxiliary neutral ligands on iridium(III) complexes were prepared. Using those ligands, α-diimine-ligated heteroleptic iridium(III) complexes with 2,4-difluorophenylpyridine as the primary cyclometalating ligand were synthesized by a conventional two-step synthesis followed by the anion exchange reaction using NH4PF6. The physical features such as spectroscopic, electrochemical and electrogenerated chemiluminescence (ECL) properties for the newly prepared complexes were characterized and compared to that of well-known tris(2,2′-bipyridine)rutheniun(II), [Ru(bpy)3](PF6)2, and previously reported (2,2′-bipyridine)bis[2-(2,4-difluorophenyl)pyridine]iridium(III), [Ir(dfppy)2(bpy)](PF6) (2), complex as the reference. All the iridium(III) complexes synthesized showed strong green emission and higher ECL intensities compared to the well-known Ru(bpy)32 +. The iridium(III) complexes containing α-diimine ligands with electron donating dimethyl, trimethylsilyl, and triphenylsilyl groups on bpy showed the increased ECL intensities compared to that of the reference (2). Among those iridium(III) complexes, the complex ligated with 5-(trimethylsilyl)-2,2′-bipyridine and 2,4-difluorophenylpyridine showed the most intense ECL responses and exhibited ECL intensities as high as 7.6 times greater than that of the reference (2). However, the iridium(III) complexes containing α-diimine ligands containing more conjugated carbon-carbon triple bond showed the decreased ECL intensities compared to that of the complexes with no triple bond conjugation.
| Original language | English |
|---|---|
| Pages (from-to) | 83-90 |
| Number of pages | 8 |
| Journal | Journal of Electroanalytical Chemistry |
| Volume | 775 |
| DOIs | |
| Publication status | Published - 2016 Aug 15 |
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All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Chemical Engineering(all)
- Electrochemistry
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Electrogenerated chemiluminescence from newly synthesized α-diimine-ligated heteroleptic iridium(III) complexes. / Kang, Tae Kyeong; Kang, Chang Hoon; Lee, Jihoon; Kim, Shin Han; Kim, Byeong Hyo; Lee, Wonyong.
In: Journal of Electroanalytical Chemistry, Vol. 775, 15.08.2016, p. 83-90.Research output: Contribution to journal › Article
TY - JOUR
T1 - Electrogenerated chemiluminescence from newly synthesized α-diimine-ligated heteroleptic iridium(III) complexes
AU - Kang, Tae Kyeong
AU - Kang, Chang Hoon
AU - Lee, Jihoon
AU - Kim, Shin Han
AU - Kim, Byeong Hyo
AU - Lee, Wonyong
PY - 2016/8/15
Y1 - 2016/8/15
N2 - A series of α-diimine ligands including alkyl-, bromo-, silyl- or silylethynyl-substituted 2,2′-bipyridines (bpy) for auxiliary neutral ligands on iridium(III) complexes were prepared. Using those ligands, α-diimine-ligated heteroleptic iridium(III) complexes with 2,4-difluorophenylpyridine as the primary cyclometalating ligand were synthesized by a conventional two-step synthesis followed by the anion exchange reaction using NH4PF6. The physical features such as spectroscopic, electrochemical and electrogenerated chemiluminescence (ECL) properties for the newly prepared complexes were characterized and compared to that of well-known tris(2,2′-bipyridine)rutheniun(II), [Ru(bpy)3](PF6)2, and previously reported (2,2′-bipyridine)bis[2-(2,4-difluorophenyl)pyridine]iridium(III), [Ir(dfppy)2(bpy)](PF6) (2), complex as the reference. All the iridium(III) complexes synthesized showed strong green emission and higher ECL intensities compared to the well-known Ru(bpy)32 +. The iridium(III) complexes containing α-diimine ligands with electron donating dimethyl, trimethylsilyl, and triphenylsilyl groups on bpy showed the increased ECL intensities compared to that of the reference (2). Among those iridium(III) complexes, the complex ligated with 5-(trimethylsilyl)-2,2′-bipyridine and 2,4-difluorophenylpyridine showed the most intense ECL responses and exhibited ECL intensities as high as 7.6 times greater than that of the reference (2). However, the iridium(III) complexes containing α-diimine ligands containing more conjugated carbon-carbon triple bond showed the decreased ECL intensities compared to that of the complexes with no triple bond conjugation.
AB - A series of α-diimine ligands including alkyl-, bromo-, silyl- or silylethynyl-substituted 2,2′-bipyridines (bpy) for auxiliary neutral ligands on iridium(III) complexes were prepared. Using those ligands, α-diimine-ligated heteroleptic iridium(III) complexes with 2,4-difluorophenylpyridine as the primary cyclometalating ligand were synthesized by a conventional two-step synthesis followed by the anion exchange reaction using NH4PF6. The physical features such as spectroscopic, electrochemical and electrogenerated chemiluminescence (ECL) properties for the newly prepared complexes were characterized and compared to that of well-known tris(2,2′-bipyridine)rutheniun(II), [Ru(bpy)3](PF6)2, and previously reported (2,2′-bipyridine)bis[2-(2,4-difluorophenyl)pyridine]iridium(III), [Ir(dfppy)2(bpy)](PF6) (2), complex as the reference. All the iridium(III) complexes synthesized showed strong green emission and higher ECL intensities compared to the well-known Ru(bpy)32 +. The iridium(III) complexes containing α-diimine ligands with electron donating dimethyl, trimethylsilyl, and triphenylsilyl groups on bpy showed the increased ECL intensities compared to that of the reference (2). Among those iridium(III) complexes, the complex ligated with 5-(trimethylsilyl)-2,2′-bipyridine and 2,4-difluorophenylpyridine showed the most intense ECL responses and exhibited ECL intensities as high as 7.6 times greater than that of the reference (2). However, the iridium(III) complexes containing α-diimine ligands containing more conjugated carbon-carbon triple bond showed the decreased ECL intensities compared to that of the complexes with no triple bond conjugation.
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U2 - 10.1016/j.jelechem.2016.05.027
DO - 10.1016/j.jelechem.2016.05.027
M3 - Article
AN - SCOPUS:84971449456
VL - 775
SP - 83
EP - 90
JO - Journal of Electroanalytical Chemistry
JF - Journal of Electroanalytical Chemistry
SN - 0368-1874
ER -