查看更多>>摘要：Circularly polarized organic light-emitting diodes (CP-OLEDs) have raised increasing interests owing to their potential application in next-generation displays. In this work, by introducing chiral alkyl chain into tridentate chelating ligand 2,6-bis(N-alkylbenzimidazol-2'-yl)benzene, three chiral Pt(II) complexes are successfully designed and synthesized. All the complexes exhibited bright green emission in dilute acetonitrile solution, while strong yellow-orange emission in highly concentrated solution. However, when these complexes are doped into polymer polymethyl methacrylate, the green emission stemmed from the intrinsic single molecule would be changed into red emission from excimer through adjusting the doping levels. More importantly, the CPL signals could be amplified by an order of magnitude in comparison with solution state. Furthermore, the monochrome devices based on these complexes were successfully fabricated, and achieved good device performances with the maximum luminance of up to 1720 cd m(-2) and electroluminescence dissymmetry values of around 2.6 x 10(-3). These results indicate that such design strategy for Pt(II) complexes with tridentate cyclometalled ligands would be important for the development of high-performance CP-OLEDs. (c) 2022 Published by Elsevier B.V.
Dibdalli, YuvarajaGaete, JoseValdebenito, CristianArroyo, Juan Luis...
6页
查看更多>>摘要：We reported the synthesis of a novel bimetallic compound with the formula [(Cp *Ru)(2)-IF] derived from 6,12-dihydroindeno[1,2-b]fluorene ligand (IFH2). This compound was characterized by H-1 and C-13 NMR, elemental analysis, FT-IR, and UV-vis. The bimetallic compound was tested as a burning rate catalyst on the thermal decomposition of ammonium perchlorate. It was assessed by differential scanning calorimetry technique (DSC) analysis to understand its catalytic behavior further. [(Cp*Ru)(2)-IF] shows a decrease in the decomposition temperature of AP to 381 degrees C, increasing the energy release to 1271 J.g(-1). In addition, this compound leads to the lowest activation energy (20.7 kJ.mol(-1)), suggesting a suitable and competitive alternative to be used as a modifier for composite solid propellants. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：The novel and highly soluble cobalt(II), copper(II) and manganese(III) phthalocyanines ((Pc-Co, Pc-Cu, and Pc-Mn) bearing 3-(5-(3,5-dimethoxyphenyl)-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl)phenol have been synthesized and characterized by FT-IR, NMR, UV-Vis and mass spectroscopic methods. Additionally, electrochemical and spectroelectrochemical properties of these phthalocyanine compounds were investigated. Due to the redox inactivity of the Cu2+ central cation of (Pc-Cu), Pc based reductions and oxidation processes are recorded. [(CoPc2-)-Pc-II]/[(CoPc2-)-Pc-I](1-) and [(CoPc2-)-Pc-II]/[(CoPc2-)-Pc-III](1+) couples for the central metal redox reactions, and [(CoPc2-)-Pc-I](1-)/[(CoPc3-)-Pc-I](2-), [(CoPc3-)-Pc-I](2-)/[(CoPc4-)-Pc-I](3-) and [(CoPc2-)-Pc-III](1+)/[(CoPc1-)-Pc-III](2+) couples for the Pc based reduction and oxidation are observed respectively with (Pc-Co). Like (Pc-Co), (Pc-Mn) also illustrated metal-based reduction processes, [Cl1--(MnPc2-)-Pc-III]/[Cl1--(MnPc2-)-Pc-II](1-) and [Cl1--(MnPc2-)-Pc-II](1-)/[Cl1--(MnPc2-)-Pc-I](2-) in addition to the Pc based [Cl1--(MnPc2-)-Pc-I](2-)/[Cl1--(MnPc3-)-Pc-I](3-), [Cl1--(MnPc3-)-Pc-I](3-) /[Cl1--(MnPc4-)-Pc-I](4-) and [Cl1--(MnPc2-)-Pc-III]/[Cl1--(MnPc1-)-Pc-III](1+) redox couples were also recorded. These redox mechanisms were supported with the characteristic spectral changes observed during the in-situ spectroelectrochemical measurements. Especially metal-based electron transfer changes caused distinct spectral and color changes, which are the desired properties of the complexes for the possible opto-electrochemical applications. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Herein, we describe an efficient copper-catalyzed cross-coupling reaction of terminal alkynes with chlorostibine 1a to synthesize a variety of Sb-alkynyl stibines. Aryl, alkyl and heteroaryl acetylenes are all tolerated. This protocol shows good functional group tolerance and broad substrate scope. These obtained Sb -alkynyl stibines were utilized as effective coupling partners to prepare 1,2,3-triazoles. The catalytic mechanism is also proposed. (C) 2022 Published by Elsevier B.V.
查看更多>>摘要：Addition of fluorine to organic molecules in the late stage of synthesis has been an increased interest in the past decade. Catalytic methods using fluoride salts as reagents could be especially useful, mainly with the use of organometallic catalysis with copper. Recent experimental advances have been reported for copper-mediated fluorination and the development of an efficient catalytic process needs a deep understanding of the reaction mechanism and the free energy profile. In this work, different mechanisms of copper-mediated fluorination of 2-(2-bromophenyl)pyridine using LCuF as reagent (L = N-heterocycle-carbene ligand) were investigated using very high level of theory, DLPNO-CCSD(T) method with up to quadruple-zeta basis set. The Cu(I)/Cu(III) mechanism is the predominant one, taking place via neutral (MS2) or cationic (MS2p) intermediates. Although the oxidative addition step has high barrier, the reductive elimination was found to be the rate-determining step. Three reaction pathways involving the Cu(II) radical mechanism was also investigated. The first one is the single-electron transfer mechanism and the second is the bromine atom transfer in the first step. Both pathways involve high free energy intermediates and are inviable. The third mechanism occurs via singlet-triplet spin crossover with bromine transfer from the oxidative addition intermediate MS2 to the LCuF initial reagent. However, the reductive elimination step from the MS2r doublet Cu(II) complex is much more difficult than the MS2 or MS2p singlets of Cu(III) complexes, leading to a very slow kinetics for this Cu(II) radical mechanism. The kinetics analysis of the theoretical free energy profile results in effective Delta G(double dagger) of 30.6 kcal mol(-1), in good agreement with an estimated experimental value and providing an important support for the Cu(I)/Cu(III) mechanism. (c) 2022 Elsevier B.V. All rights reserved.
Solmaz, UmmuhanInce, SimayYilmaz, Mustafa KemalArslan, Hakan...
10页
查看更多>>摘要：Trans-dichloro bis[N,N-dibutyl-N'-(4-chloro-benzoyl)thioureato-kappa S]palladium(II) complex (Trans-[(PdCl2)-Cl-II(HBTU-kappa S)(2)]) is formed by reaction between PdCl2 and N,N-dibutyl-N'-(4-chlorobenzoyl)thiourea (BTU) in acetonitrile. Cis-bis[N,N-dibutyl-N'-(4-chlorobenzoyl) thioureato-kappa O-2,S]palladium(II) (cis-[Pd-II(BTU-kappa S-2,O)(2)]) is obtained by recrystallization of trans-[(PdCl2)-Cl-II(HBTU-kappa S)(2)] in ethanol:dichloromethane solvent mixture. The prepared ligand coordinates with Pd(II) ion in monodentate coordination mode for trans-[(PdCl2)-Cl-II(HBTU-kappa S)(2)] and in bidentate coordination mode for cis-[Pd-II(BTU-kappa S-2,O)(2)]. Both Pd(II) complexes have been characterized by elemental analysis, FT-IR, H-1 NMR, C-13 NMR, and UV-Vis techniques. The detail structural formulations of trans-[(PdCl2)-Cl-II(HBTU-kappa S)(2)] and cis-[Pd-II(BTU-kappa S-2,O)(2)] have been defined by X-ray single-crystal diffraction. The palladium complexes were also applied as an efficient catalyst for the Suzuki-Miyaura cross-coupling reaction of aryl halides with aryl boronic acids at 110 degrees C using a very high substrate/catalyst ratio. (C) 2022 Elsevier B.V. All rights reserved.
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