2425-77-6Relevant articles and documents
Properties and sodium salicylate induced aggregation behavior of a tail-branched cationic surfactant with a hydroxyl-containing hydrophilic head
Zhang, Yongjie,Li, Yunling,Song, Yongbo,Li, Jun
, p. 105952 - 105960 (2015)
A cationic surfactant with a Guerbet-type branched tail and hydroxyl-decorated head group was synthesized and characterized. Its properties including surface activity, dynamic surface tension, wetting ability, concentration/salt induced aggregation pattern transition and rheological responses of aqueous solutions were measured and analyzed. It was found that this new amphiphile possessed powerful surface activity (γcmc = 25.26 mN m-1) and could enhance the spreading of an aqueous solution on a low energy solid surface (paraffin surface); while dynamic surface tension measurements implied that the diffusion rate of surfactant molecules, influenced by the presence of hydroxyl groups, had an impact on the wetting process. It was determined that the introduction of branching hydrophobes and hydroxyls into the amphiphilic material crucially contributed to the superior performances. Moreover, a visual transition with increasing concentration of its aqueous solution was observed, while the addition of the structure-forming additive sodium salicylate (NaSal) could highly improve the viscosity by inducing the micellar growth in the cationic system which was researched by rheological experiments. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were operated to investigate the transformation of aggregates which are responsible for the concentration/salt induced phase behavior transition or rheological responses.
Methylene-Linked Bis-NHC Half-Sandwich Ruthenium Complexes: Binding of Small Molecules and Catalysis toward Ketone Transfer Hydrogenation
Botubol-Ares, José Manuel,Cordón-Ouahhabi, Safa,Moutaoukil, Zakaria,Collado, Isidro G.,Jiménez-Tenorio, Manuel,Puerta, M. Carmen,Valerga, Pedro
supporting information, p. 792 - 803 (2021/04/06)
The complex [Cp*RuCl(COD)] reacts with LH2Cl2 (L = bis(3-methylimidazol-2-ylidene)) and LiBun in tetrahydrofuran at 65 °C furnishing the bis-carbene derivative [Cp*RuCl(L)] (2). This compound reacts with NaBPh4 in MeOH under dinitrogen to yield the labile dinitrogen-bridged complex [{Cp*Ru(L)}2(μ-N2)][BPh4]2 (4). The dinitrogen ligand in 4 is readily replaced by a series of donor molecules leading to the corresponding cationic complexes [Cp*Ru(X)(L)][BPh4] (X = MeCN 3, H2 6, C2H4 8a, CH2CHCOOMe 8b, CHPh 9). Attempts to recrystallize 4 from MeNO2/EtOH solutions led to the isolation of the nitrosyl derivative [Cp*Ru(NO)(L)][BPh4]2 (5), which was structurally characterized. The allenylidene complex [Cp*Ru═C═C═CPh2(L)][BPh4] (10) was also obtained, and it was prepared by reaction of 2 with HCCC(OH)Ph2 and NaBPh4 in MeOH at 60 °C. Complexes 3, 4, and 6 are efficient catalyst precursors for the transfer hydrogenation of a broad range of ketones. The dihydrogen complex 6 has proven particularly effective, reaching TOF values up to 455 h-1 at catalyst loadings of 0.1% mol, with a high functional group tolerance on the reduction of a broad scope of aryl and aliphatic ketones to yield the corresponding alcohols.
Diastereoselective synthesis of functionally substituted alkene dimers and oligomers, catalysed by chiral zirconocenes
Kovyazin, Pavel V.,Abdullin, Il'giz N.,Parfenova, Lyudmila V.
, p. 144 - 152 (2018/11/21)
The research addresses the reaction of terminal alkenes and propene with AlR3 (R = Me, Et) in the presence of chiral Zr complexes, rac-[Y(η5-C9H10)2]ZrCl2 (Y = C2H4, SiMe2) or (NMI)2ZrCl2 (NMI- η5–neomenthylindenyl), and methylaluminoxane. The effect of reaction conditions, catalyst and trialkylalane structure on the substrate conversion and the reaction chemo- and stereoselectivity has been studied. The reaction predominantly goes via the stage of alkene methyl(ethyl)zirconation with subsequent introduction of substrate molecules into the Zr-C bond. As a result, a diastereoselective one-pot method for the synthesis of functionally substituted linear terminal alkene dimers and propene oligomers was developed.