Various symmetrically and asymmetrically substituted N-heterocyclic carbene (NHC) ligands bearing aliphatic nitrogen-containing side groups have been synthesised. In our attempts to isolate the corresponding second-generation Grubbscatalysts, we were unsuccessful when using the symmetrical aliphatic NHC ligands. For the asymmetrical ligands bearing an aliphatic moiety on one side and an aromatic mesityl
NewDelhiMetallo-β-lactamase-1 (NDM-1), a Zn (II)-dependent enzyme, can catalyze the hydrolysis of almost all β-lactam antibiotics including carbapenems, resulting in bacterial antibiotic resistance, which threatens public health globally. Based on our finding that H2dedpa is as an efficient NDM-1inhibitor, a series of H2dedpa derivatives was systematically prepared. These compounds exhibited significant
8 10, 12), were synthesized and characterized by 1H NMR, 13C NMR, ESI-MS, and elemental analysis. The surface activity and micellization behavior at acidic, neutral, and basic conditions were characterized by equilibrium surface tension and fluorescence techniques. It was found that the surface activity of Di-CnP depends on the pH of aqueous solutions due to the protonation state of surfactant molecules
具有2-吡咯烷酮头基,N,N'-二烷基-N,N'-二(乙基-2-吡咯烷酮)乙二胺(Di-C n P,其中n = 6,8合成并通过1 H NMR,13 C NMR,ESI-MS和元素分析对其进行表征。通过平衡表面张力和荧光技术表征了在酸性,中性和碱性条件下的表面活性和胶束化行为。发现当pH变化时,由于表面活性剂分子的质子化状态,Di-C n P的表面活性取决于水溶液的pH。新化合物的cmc和γcmc较低与m -2- m型常规阳离子Gemini表面活性剂和葡糖酰胺型非离子Gemini表面活性剂相比。荧光数据证实当浓度高于cmc时会形成胶束。由于胶束化在表面活性剂应用(例如增溶,微乳液和相关技术)中至关重要,因此采用这种新型Gemini表面活性剂在不同pH值下cmc的显着差异来溶解环己烷。初步结果确实表明,Di-C n P的增溶能力可以通过pH来调节。
Synthesis and Surface Properties of a pH-Regulated and pH-Reversible Anionic Gemini Surfactant
作者:Jing Lv、Weihong Qiao、Chongqiao Xiong
DOI:10.1021/la5016669
日期:2014.7.22
synthesized in two steps. Their surfaceproperties and aggregation behavior were studied in aqueous solution using pH titration, surface tension, zeta potential, dynamic light scattering (DLS), transmission electron microscopy (TEM), and fluorescence measurements. On the basis of the pKa values obtained, surface tension was measured, as well as key surfaceproperty parameters. Combined with the zeta
分两步合成了一系列新的N,N'-二烷基-N,N'-二乙酸乙二胺,但碳尾部的长度不同(分别为8、10和12)。在水溶液中使用pH滴定,表面张力,ζ电位,动态光散射(DLS),透射电子显微镜(TEM)和荧光测量研究了它们的表面性质和聚集行为。根据p K a获得的值,测量表面张力以及关键的表面性能参数。结合Zeta电位和DLS结果,实验产生了囊泡,并通过随后的TEM和荧光测量反映了其pH可控性。发现pH可转换性通过透光率是可逆的。十二烷在水中在不同pH值下的乳液稳定性表明,乳液类型在O / W乳液类型的“开”和“ W / O”的“关”之间反转。
Novel synthesized anionic gemini and monomeric surfactants bearing sulphonate group as petro-dispersing/collecting agents: Design, characterization and surface-active properties
作者:Mohamed A. Abo-Riya、Sharbat A. Baker
DOI:10.1016/j.molstruc.2022.134502
日期:2023.2
Conventional and gemini anionic sulphonate surfactants of variable alkyl chain length (8, 10, and 12 carbon atoms), were synthesized by three steps reactions using ethylenediamine, alkyl halides and sodium 3-chloro-2-hydroxypropane-1-sulfonate. Various spectroscopic tools (i.e., 1H and 13C NMR and IR spectra) were used to clarify the structures of synthesized surfactants. The solution surface properties of synthesized
使用乙二胺、烷基卤化物和 3-chloro-2-hydroxypropane-1-sulfonate 通过三步反应合成了具有可变烷基链长度(8、10 和 12 个碳原子)的常规和双子阴离子磺酸盐表面活性剂。各种光谱工具(即1 H 和13 C NMR 和红外光谱)用于阐明合成表面活性剂的结构。通过临界胶束浓度(CMC)研究了合成表面活性剂的溶液表面性质。测量每个表面活性剂分子的最大表面积和最小表面积。此外,通过自由吸附能参数估算合成表面活性剂的吸附和胶束化性能(△G一个d秒0) 和胶束化 (△G米一世C0) 进行了测量。此外,合成的表面活性剂作为石油收集剂或分散剂的行为已经在不同盐度的水中以固体和稀释形式进行了研究。结果表明,合成的表面活性剂在不同盐度的水溶液中具有优异的石油分散性能。而通过提高这些化合物的疏水性可以提高分散效果。此外,所有合成的常规和双子阴离子表面活性剂都具有比在溶液中胶束化更高的表面吸附能力。