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1.
Dmitriy S. Yambulatov Stanislav A. Nikolaevskii Mikhail A. Kiskin Kirill V. Kholin Mikhail N. Khrizanforov Yulia G. Budnikova Konstantin A. Babeshkin Nikolay N. Efimov Alexander S. Goloveshkin Vladimir K. Imshennik Yurii V. Maksimov Evgeny M. Kadilenko Nina P. Gritsan Igor L. Eremenko 《Molecules (Basel, Switzerland)》2021,26(10)
The reaction of the redox active 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-BIAN) and iron(II) iodide in acetonitrile led to a new complex [(dpp-BIAN)FeIII2] (1). Molecular structure of 1 was determined by the single crystal X-ray diffraction analysis. The spin state of the iron cation in complex 1 at room temperature and the magnetic behavior of 1 in the temperature range of 2–300 K were studied using Mossbauer spectroscopy and magnetic susceptibility measurements, respectively. The neutral character of dpp-BIAN in 1 was confirmed by IR and UV spectroscopy. The electrochemistry of 1 was studied in solution and solid state using cyclic voltammetry. The generation of the radical anion form of the dpp-BIAN ligand upon reduction of 1 in a CH2Cl2 solution was monitored by EPR spectroscopy. 相似文献
2.
Direct Synthesis of Functionalized High‐Molecular‐Weight Polyethylene by Copolymerization of Ethylene with Polar Monomers
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Shengyu Dai Prof. Changle Chen 《Angewandte Chemie (International ed. in English)》2016,55(42):13281-13285
The introduction of even a small amount of polar functional groups into polyolefins could excise great control over important material properties. As the most direct and economic strategy, the transition‐metal‐catalyzed copolymerization of olefins with polar, functionalized monomers represents one of the biggest challenges in this field. The presence of polar monomers usually dramatically reduces the catalytic activity and copolymer molecular weight (to the level of thousands or even hundreds Da), rendering the copolymerization process and the copolymer materials far from ideal for industrial applications. In this contribution, we demonstrate that these obstacles can be addressed through rational catalyst design. Copolymers with highly linear microstructures, high melting temperatures, and very high molecular weights (close to or above 1 000 000 Da) were generated. The direct synthesis of polar functionalized high‐molecular‐weight polyethylene was thus achieved. 相似文献
3.
A series of unsymmetrical complexes of 2,3-bis(2-phenylphenyl)-butanediimine nickel(II) dibromide (complex 1), 1,4-bis(2-isopropyl-6-methylphenyl)-acenaphthenediimine nickel(II) dibromide (complex 2) and meso- and rac-1,4-bis (2,4-di-tert-butyl-6-methylphenyl)-acenaphthenediimine nickel(II) dibromide (meso-3 and rac-3) were synthesized and activated by methylaluminoxane (MAO) for ethylene polymerization. By 13C NMR characterization, meso- and rac-stereo-isomers were detected in the condensation products resulting from the reaction of unsym-substituted anilines with diketones. It was notable that meso- and rac-isomers in ligand 1 or ligand 2 could not be separated owing to their interconversion, however, meso- and rac-isomers in ligand 3 could be isolated and identified by X-ray diffraction and NMR analysis. At low polymerization temperatures, complex 1/MAO afforded polyethylene with bimodal molecular weight distribution, while complex 2/MAO prepared polyethylene with single-modal distribution. Moreover, by raising polymerization temperature or extending time of catalyst aging, bimodal molecular weight distribution polyethylene was also produced by complex 2/MAO. The hypothesis of bimodal molecular weight distribution polyethylene synthesized by unsymmetrical α-diimine nickel(II) complexes was supported that the molecular weight of polyethylene produced by rac-3/MAO was significantly higher than that produced by meso-3/MAO under identical polymerization conditions. A unique methodology to prepare polyethylene with bimodal molecular weight distribution was demonstrated. 相似文献
4.
Wenyong Dong Yoshiaki Yoshida Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2021,59(6):502-509
A series of amines are applied as catalysts in the aminolysis reactions of five-membered cyclic carbonate (5CC). Kinetic results display that TBD, which has a guanidine structure, exhibits the best catalytic efficacy and the reaction rate constant is about 100 times higher than the blank system without catalyst. The reaction medium, NMP is found to be as both solvent and promoter in the aminolysis of 5CC. Finally, with TBD and NMP as catalyst and solvent, respectively, the polymerization of bis-functional 5CC (B5CC) and 1, 6-diaminohexane can proceed almost 100% at room temperature in less than 4 h to obtain poly(hydroxyurethane)s (PHUs) with moderate molecular weight. 相似文献
5.
Dr. Anna Kamecka Prof. Andrzej Kapturkiewicz M.Sc. Patryk Wójcik Prof. Kinga Suwińska Dr. Joanna Masternak 《欧洲无机化学杂志》2023,26(33):e202300438
The paper deals with the synthesis of a series of cationic [Pt(ppz)2(N^N)]2+ complexes containing deprotonated 1-phenyl-1H-pyrazole as cyclometallating (C^N) ligands and α-diimines (N^N) in the form of water-soluble salts with OTf− (trifluoromethanesulfonate) counter ions. These complexes were obtained from cis-[Pt(ppz)2Cl2] through chloride ligands substitution with α-diimines. The complexes were identified by means of NMR spectroscopy and their molecular structures were confirmed by X-ray crystallography. The photophysical properties of these complexes were studied in detail. These complexes showed strong luminescence in MeOH/EtOH 1 : 1 glasses at 77 K but were almost non-emitting in MeCN solutions at room temperature. Their emission properties were compared to analogues IrIII complexes. 相似文献
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7.
Treatment of the unsymmetrical β-iminoamine ligands [PhCN(Ar)CHCNH(Ar)Me] with the zerovalent complex Pd(dba)2 in the presence of the methallyloxyphosphonium salt, gives high yields of the cationic β-diimine complexes [PhCN(Ar)CH2CN(Ar)(Me)Pd(η3-C4H7)]+[PF6]− (Ar = 2-Me-C6H4 (7); 2-MeO-C6H4 (8); 2,6-Me2-C6H3 (9); 2,6-iPr2-C6H3 (10)). All the new complexes have been characterised by NMR and IR spectroscopy. The structure of the cationic methallyl palladium complex (10) has been solved by X-ray crystallography. 相似文献
8.
《Mendeleev Communications》2022,32(5):582-584
Reactivity of ytterbium and magnesium complexes of gallylenes against carbon dioxide and diphenylketene has been assessed. Ytterbium complex of redox-active gallylene [{(dpp-bian)Ga}2Yb(DME)2] (dpp-bian = 1,2-bis[(2,6-diiso-propylphenyl)imino]acenaphthene) on treatment with CO2 gives complex [(dpp-bian)Ga(DME)Me], while the treatment of magnesium-stabilized gallylene[{(dpp-bian)Ga}2Mg(DME)2] with Ph2CCO affords cycloadduct [(dpp-bian)(Ph2CCO)GaMe]. 相似文献
9.
Dr. Vladimir A. Dodonov Weixing Chen Prof. Dr. Yanxia Zhao Prof. Dr. Alexandra A. Skatova Prof. Dr. Peter W. Roesky Prof. Dr. Biao Wu Prof. Dr. Xiao-Juan Yang Prof. Dr. Igor L. Fedushkin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(35):8259-8267
Digallane [L1Ga−GaL1] ( 1 , L1=dpp-bian=1,2-[(2,6-iPr2C6H3)NC]2C12H6) reacts with RN=C=O (R=Ph or Tos) by [2+4] cycloaddition of the isocyanate C=N bonds across both of its C=C−N−Ga fragments to afford [L1(O=C−NR)Ga−Ga(RN−C=O)L1] (R=Ph, 3 ; R=Tos, 4 ). The reactions with both isocyanates result in new C−C and N−Ga single bonds. In the case of allyl isocyanate, the [2+4] cycloaddition across one C=C−N−Ga fragment of 1 is accompanied by insertion of a second allyl isocyanate molecule into the Ga−N bond of the same fragment to afford compound [L1Ga−Ga(AllN− C=O)2L1] ( 5 ) (All=allyl). In the presence of Na metal, the related digallane [L2Ga−GaL2] ( 2 ; L2=dpp-dad=[(2,6-iPr2C6H3)NC(CH3)]2) is converted into the gallium(I) carbene analogue [L2Ga:]− ( 2 A ), which undergoes a variety of reactions with isocyanate substrates. These include the cycloaddition of ethyl isocyanate to 2 A affording [Na2(THF)5]{L2Ga[EtN−C(O)]2GaL2} ( 6 ), cleavage of the N=C bond with release of 1 equiv. of CO to give [Na(THF)2]2[L2Ga(p-MeC6H4)(N−C(O))2−N(p-MeC6H4)]2 ( 7 ), cleavage of the C=O bond to yield the di-O-bridged digallium compound [Na(THF)3]2[L2Ga-(μ-O)2-GaL2] ( 8 ), and generation of the further addition product [Na2(THF)5][L2Ga(CyNCO2)]2 ( 9 ). Complexes 3 – 9 have been characterized by NMR (1H, 13C), IR spectroscopy, elemental analysis, and X-ray diffraction analysis. Their electronic structures have been examined by DFT calculations. 相似文献
10.
A Csp3-Csp3 coupling production of the original ligand molecule [(CMeN(2,6-iPr2C6H3))2]2 (1) and an antimony ionic compound with α-diimine ligand [LH3]+[SbCl4]-(2, L = [(2,6-iPrC6H3)NC(Me)]2) were synthesized and characterized by 1H NMR, elemental analysis and single-crystal X-ray structural analysis. The crystal of compound 1 belongs to the orthorhombic system, space group Pbca with a = 21.173(4), b = 10.1639(17), c = 22.954(4) , V = 4939.8(14) 3, C56H78N4, Mr = 807.22, Z = 4, Dc = 1.085 g/cm3, μ(MoKα) = 0.062 mm-1, F(000) = 1768, S = 0.998, the final R = 0.0593 and wR = 0.1616 for 6481 observed reflections (Ⅰ > 2σ(Ⅰ)) and R = 0.0819 and wR = 0.1805 for all 28753 data. The crystal of compound 2 belongs to the triclinic system, space group P with a = 10.930(2), b = 12.553(2), c = 12.561(3) , α = 89.780(7), β = 82.861(6), γ = 68.598(4)o, V = 1590.5(5) 3, C28H43Cl4N2Sb, Mr = 671.19, Z = 2, Dc = 1.401 g/cm3, μ(MoKα) = 1.222mm-1, F(000) = 688, S = 0.989, the final R = 0.0294 and wR = 0.0616 for 7578 observed reflections (Ⅰ > 2σ(Ⅰ)) and R = 0.0366 and wR = 0.0639 for all 16515 data. Complex 1 can be rationalized as a result of Csp3-Csp3 coupling of two ligand molecules. The reaction of corres- ponding potassium salts with Sb(Ⅲ) chloride resulted in the antimony complex 2, in which the cationic moiety [LH3]+ is balanced by the presence of [SbCl4]- anion. 相似文献