- Bright and Long-Lived Emission from a Starburst-Type Arylborane-Appended Polypyridyl Ruthenium(II) Complex
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The starburst-type arylborane-appended polypyridyl RuII complex [Ru{4,7-bis({dimesityl}boryldurylethynyl)-1,10-phenanthroline}3]2+ (1) was synthesized, and its spectroscopic and photophysical properties were evaluated. In the excited state of the complex, intramolecular charge transfer (CT) between the π orbital of the aryl group and the vacant p orbital of the boron atom [π(aryl)–p(B) CT] interacts synergistically with metal-to-ligand charge transfer (MLCT). The synergistic CT interactions in 1 are more effective than those in previously reported arylborane-appended polypyridyl RuII complexes and lead to bright (molar absorption coefficient of the MLCT band = 7.2 × 104 m–1 cm–1, emission quantum yield = 0.29) and long-lived emission (8.7 μs) of 1 in CH3CN at 298 K. The unique emission characteristics of 1 are discussed in detail together with its electrochemical properties and time-dependent DFT (TD-DFT) calculations.
- Nakagawa, Atsushi,Ito, Akitaka,Sakuda, Eri,Fujii, Sho,Kitamura, Noboru
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- Characteristic spectroscopic and photophysical properties of tricarbonyl rhenium(i) complexes having multiple arylborane charge transfer units
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An introduction of two arylborane charge transfer (CT) units to the periphery of 1,10-phenanthroline (B2phen) or 2,2-bipyridine (B2bpy) in a tricarbonyl rhenium(I) diimine complex ( fac-[Re(CO)3(B2phen)Br] = ReB2phen or fac-[Re(CO)3-(B2bpy)Br] = ReB2bpy) resulted in unique redox, spectroscopic, and photophysical properties of the complex. In particular, the presence of the two arylborane units in the complex can enhance its metal-to-ligand CT absorption intensity in the visible region and the radiative rate constant, compared to those of the complexes without and with the single arylborane unit in the ligand. The single X-ray crystal structure of ReB2phen is also reported.
- Kang, Yuanyuan,Ito, Akitaka,Sakuda, Eri,Kitamura, Noboru
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- Organic electroluminescence material and organic photoelectric device
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The invention provides a compound with a structure as shown in formula I. The invention also provides an application of the compound in an organic photoelectric device and the organic photoelectric device. The compound provided by the invention has a ther
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Paragraph 0129; 0134; 0135
(2017/07/19)
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- A highly efficient red-emitting ruthenium complex with 3,5-difluorophenyl substituents
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Five 3,5-difluorophenyl-substituted ruthenium complexes [Ru(bpy)2(dfpbpy)(ClO4)2] (Ru-Fbpy-bpy; bpy=bipyridine, dfpbpy=5,5′-di(3,5-difluorophenyl)-2,2′-bipyridine), [Ru(dpp)2(dfpbpy)(ClO4)2] (Ru-Fbpy-dpp; dpp=4,7-diphenyl-1,10-phenanthroline), [Ru(dpp)2(dfpphen)(ClO4)2] (Ru-Fphen-dpp; dfpphen=5,5′-di(3,5-difluorophenyl)-1,10-phenanthroline), [Ru(dpp)2(4,7-dfpphen)(ClO4)2] (Ru-Fdpp-dpp; 4,7-dfpphen=4,7-di(3,5-difluorophenyl)-1,10-phenanthroline), and [Ru(4,7-dfpphen)3(AsF6)2] (Ru-Fdpp) were synthesized, and their photophysical, electrochemical, and electroluminescent properties were studied systematically. The introduction of the electron-withdrawing group 3,5-difluorophenyl leads to a redshift of the emission of the ruthenium complexes. In addition, the 3,5-difluorophenyl substituent extends the π conjugation of the ligand, and thus facilitates the metal-to-ligand charge-transfer process of the complexes. All the complexes display orange-red phosphorescent emissions centered at 638, 638, 624, 614, and 605 nm, respectively. Density functional theory calculations show that the lowest unoccupied molecular orbital of Ru-Fbpy-dpp, Ru-Fphen-dpp, and Ru-Fdpp-dpp are all distributed on the 3,5-difluorophenyl-substituted ligand. By using these complexes as emitters, highly luminescent single-layer devices are obtained. The optimized device based on Ru-Fdpp exhibits the highest luminous efficiency and power efficiency of 4.19 cd A-1 and 1.46 lm W-1, respectively. Bright ideas: Five 3,5-difluorophenyl-substituted ruthenium complexes have been synthesized and characterized. The photoluminescent efficiencies of the complexes improved after introduction of an electron-withdrawing substituent (see scheme). The complexes are suitable as dopant light-emitting materials for organic light-emitting diodes.
- Zhu, Yingying,Fei, Teng,Ma, Yuguang
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- The synthesis of aromatic diazatricycles from phenylenediamine-bis(methylene Meldrum's acid) derivatives
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The thermocyclisation of phenylenediamine-bis(methylene Meldrum's acid) derivatives has been investigated. Those of o-phenylenediamines give 1,10-phenanthroline derivatives, while those of m- and p-phenylenediamines lead to the preferential formation of angular diazatricycles. Thus, for example, the di-Meldrum's acid derivative of 2,5-dichloro-1,4-phenylenediamine gives, via ipso-substitution, the unexpected angular product 19.
- Graf, Gabriele Ina,Hastreiter, Daniel,Da Silva, Luiz Everson,Rebelo, Ricardo Andrade,Montalban, Antonio Garrido,McKillop, Alexander
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p. 9095 - 9100
(2007/10/03)
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- Synthesis of 4,7-Disubstituted Phenanthrolines as Key Building Blocks for the First Preparation of Macrocyclic Mono- and Bisphenanthrolines with exo-Coordination Sites
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The preparation of various 4,7-bisalkynylated phenanthrolines and 4,7-bis(4-hydroxyphenoxy)phenanthroline as well as their use in the synthesis of the first macrocyclic phenanthrolines and bisphenanthrolines with exo-coordination sites is described.
- Schmittel, Michael,Ganz, Andrea
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p. 710 - 712
(2007/10/03)
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