- Bis-Heteroleptic Cationic Iridium(III) Complexes Featuring Cyclometalating 2-Phenylbenzimidazole Ligands: A Combined Experimental and Theoretical Study
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In this report, we investigate a new family of cationic iridium(III) complexes featuring the cyclometalating ligand 2-phenylbenzimidazole and ancillary ligand 4,4′-dimethyl-2,2′-bipyridine. Our benchmark complex IrL12 (L1 = 2-phenylbenzimidazole) displays emission properties similar to those of the archetypical complex 2,2′-dipyridylbis(2′,4′-phenylpyridine)iridium(III) in deaerated CH3CN (Φ = 0.20, λem = 584 nm and Φ = 0.14, λem = 585 nm, respectively) but exhibits a higher photoluminescence quantum yield in deaerated CH2Cl2 (Φ = 0.32, λem = 566 nm and Φ = 0.20, λem = 595 nm, respectively) and especially a lower nonradiative constant (knr = 6.6 × 105 s-1 vs knr = 1.4 × 106 s-1, respectively). As a primary investigation, we explored the influence of the introduction of electron-donating and electron-withdrawing groups on the benzimidazole moiety and the synergetic effect of the substitution of the cyclometalating phenyl moiety at the para position with the same substituents. The emission energy displays very good correlation with the Hammett constants of the introduced substituents as well as with ΔEredox values, which allow us to ascribe the phosphorescence of these series to emanate mainly from a mixed metal/ligand to ligand charge transfer triplet excited state (3M/LLCT*). Two complexes (IrL52 and IrL82) display a switch of the lowest triplet excited state from 3M/LLCT* to ligand centered (3LC*), from the less polar CH2Cl2 to the more polar CH3CN. The observed results are supported by (TD)-DFT computations considering the vibrational contributions to the electronic transitions. Chromaticity diagrams based on the maximum emission wavelength of the recorded and simulated phosphorescence spectra demonstrate the strong promise of our complexes as emitting materials, together with the very good agreement between experimental and theoretical results.
- Ciambrone, Charles,Lafargue-Dit-Hauret, William,Lano?, Pierre-Henri,Latouche, Camille,Loiseau, Frédérique,Martìnez-Vollbert, Emiliano
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p. 3033 - 3049
(2022/02/23)
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- Nucleophilic aromatic substitution reactions under aqueous, mild conditions using polymeric additive HPMC
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The use of the inexpensive, benign, and sustainable polymer, hydroxypropyl methylcellulose (HPMC), in water enables nucleophilic aromatic subsitution (SNAr) reactions between various nucleophiles and electrophiles. The mild reaction conditions facilitate a broad functional group tolerance that can be utilized for subsequent derivatization for the synthesis of pharmaceutically relevant building blocks. The use of only equimolar amounts of all reagents and water as reaction solvent reveals the greenness and sustainability of the methodology presented herein.
- Ansari, Tharique N.,Borlinghaus, Niginia,Braje, Leon H.,Braje, Wilfried M.,Handa, Sachin,Ogulu, Deborah,Wittmann, Valentin
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supporting information
p. 3955 - 3962
(2021/06/17)
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- FUSED HETEROCYCLIC COMPOUND AND USE THEREOF
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A fused heterocyclic compound of formula (1): wherein, A1 and A2 represent a nitrogen atom or the like, R1, R2, R3 and R4 represent a halogen atom or the like, R2 and R3 represent a halogen atom or the like, R5 represents a C1-C6 chain hydrocarbon group optionally substituted with one or more halogen atoms, or the like, R6 and R7 represent a C1-C4 chain hydrocarbon group substituted with one or more halogen atoms, or the like, and n represents 0 or 1, has an excellent noxious arthropod controlling effect.
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Page/Page column 250-251
(2010/11/17)
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- Imidazopyridinone derivatives and their use as phosphodiesterase inhibitors
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A compound (Ia): wherein the variables are defined in the specification, its prodrug or a pharmaceutically acceptable salt thereof useful in the treatment of angina, hypertension etc.
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