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41.
十二烷基季铵盐及其与十二烷基硫酸钠混合体系的表面活性 总被引:13,自引:0,他引:13
通过表面张力测定,研究了十二烷基季铵盐C12H25N(CnH2n+1)3Br(n=1,2,3,4)及其与十二烷基硫酸钠混合体系的表面活性,应用规则溶液理论,计算了混合体系表面吸附层和胶团的组成及分子相互作用参数,对于季铵盐、极性基影响大:cmc随n增加而下降,γcmc则先上升,后下降,自极性基碳链的空间阻碍、疏水、弯曲效应,以及电荷屏蔽效应可对此予以解释,对于混合体系,极性基大小对其表面活性及胶团 相似文献
42.
G. Yu. Ishmuratov M. P. Yakovleva R. Ya. Kharisov G. I. Kunafina E. V. Gorobets A. V. Kuchin G. A. Tolstikov 《Russian Chemical Bulletin》1997,46(8):1465-1467
A convergent synthesis of octadeca-2E, 13Z-dienyl acetate, a pheromone component ofSynanthedon tipuliformis C., has been developed. The synthesis is based on cross-coupling of 8-iodooct-2E-en-I-ol THP ether with dec-5Z-enyl bromide catalyzed by CuBr.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1529–1531, August, 1997. 相似文献
43.
Mohammad Ali Zolfigol Khodabakhsh Niknam Mojtaba Bagherzadeh Arash Ghorbani‐Choghamarani Nadiya Koukabi Maryam Hajjami Eskandar Kolvari 《中国化学会会志》2007,54(5):1115-1118
Tribromoisocyanuric acid (TBCA) and Oxone®‐MX systems were used as effective oxidizing agents for the oxidation of thiols to their corresponding disulfides under mild conditions at room temperature with good to excellent yields. 相似文献
44.
Regioselective oxidative bromination of electron-rich aromatic rings has been studied using potassium bromide as a bromine source in the presence of benzyltriphenylphosphonium peroxymonosulfate as oxidant under nearly neutral reaction conditions. In most cases we obtained monobrominated derivatives regioselectively and in good to high yields without the aid of strong acids. 相似文献
45.
J. -L. Fortier P. -A. Leduc P. Picker J. E. Desnoyers 《Journal of solution chemistry》1973,2(5):467-475
The enthalpies of dilution of NaCl, Me4NBr, andn-Bu4NBr were measured in water at 25°C with a new flow microcalorimeter. The data were analyzed with a polynomial equation, and the derived relative apparent molal enthalpies L are in good agreement with literature values. Provided care is taken that mixing is complete, flow calorimeters are as reliable and much less time-consuming than cell-type instruments for enthalpies of dilution measurements. 相似文献
46.
E. V. Ivanov E. Yu. Lebedeva V. K. Abrosimov N. G. Ivanova 《Russian Chemical Bulletin》2004,53(4):751-757
Densities of Bun
4NBr solutions in MeOH, MeOD, and CD3OH were measured at salt concentrations of up to 1.5 solvomolality units (nearly 2.63·10–2 mole fraction) at 278.15, 288.15, 298.15, 308.15, and 318.15 K. The limiting partial molar volumes of Bun
4NBr dissolved in these alcohols were calculated. The isotope effects in the volume characteristics of the stoichiometric mixture of ions, [Bun
4N+ + Br–], are mainly due to the vibrational changes in the solvent structure upon deuteration of different molecular fragments. Structural transformations in infinitely dilute solution of Bun
4NBr in methanol are governed by non-specific solvation of the symmetrical Bun
4N+ cation. 相似文献
47.
Polymer-supported DABCO–palladium complex was observed as to be efficient and reusable catalytic system for the Suzuki–Miyaura cross-coupling reaction. In the presence of 0.25 mol % of the polymer-supported DABCO–palladium complex, a variety of aryl bromides were coupled with arylboronic acids efficiently in an aqueous ethanol at room temperature under air. Moreover, the reaction was very rapid, and the catalyst could be recovered readily from the reaction by simple filtration and could be reused at least five times. 相似文献
48.
在吡啶溶剂中氯化镍催化的溴代芳烃自身偶联反应 总被引:1,自引:0,他引:1
Pyridine was used as a solvent for homocoupling of aryl bromides catalyzed by nickel chloride/triarylphosphinein the presence of zinc and recycled easily.Triphenylphosphine was the best ligand for nickel in this coupling reac-tion. 相似文献
49.
50.
A new kind of multilayer of didodecyldimethylammonium bromide (DDAB) and 1:12 phosphomolybdic anions (PMo12) was achieved on the surface of a wax-impregnated graphite (WIG) electrode by ion exchange and electrostatic interaction.
The characterization and electrochemical behavior of the multilayer films of DDAB/PMo12 is described in detail. The chemically modified electrode was shown to exhibit an excellent electrocatalytic activity toward
the reduction of BrO3
– anion in 0.5 M H2SO4 and possesses several attractive features, such as simple preparation, fast response, good stability, etc.
Electronic Publication 相似文献