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有机试剂结构与性质的研究 Ⅰ.3,4-二羟基偶氮苯的衍生物的酸碱平衡及存在形式的研究 总被引:2,自引:3,他引:2
应用分光光度法及量子化学方法研究了3,4-二羟基偶氮苯的衍生物的酸碱平衡及其存在的形式(在表面活性剂不存在和存在下)。初步探讨了表面活性剂存在下,吸收光谱变化的可能机理。 相似文献
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本文研究了在阴离子表面活性剂十二烷基硫酸钠(简称SLS)存在下,铜(Ⅰ)与5[(3,5-二溴-2-吡啶)偶氮]-2,4-二氨基甲苯(简称3,5-二溴-PADAT)的显色反应和光度特性,试验了用该体系测定微量铜的条件和方法。 相似文献
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胶束增敏 2,3,7-三羟基-9-[3,5-二溴-4-(2,5-二羟基)苯偶氮]苯基荧光酮与锆(Ⅳ)显色反应的研究 总被引:4,自引:0,他引:4
系统研究了在混合表面活性剂 CTMAB-Tween-80 存在下,新显色剂 2,3,7-三羟基-9-[3,5-二溴-4-(2,5-二羟基)苯偶氮]苯基荧光酮(DBAPPF) 与 Zr(Ⅳ)的显色反应及其光度性质并讨论了混合表面活性剂对显色反应的增敏机理.在浓度为 0.4mol/L 的 HCl 介质中,新试剂与 Zr(Ⅳ)和表面活性剂形成胶束络合物,混合表面活性剂有较强的增敏作用,络合物最大吸收波长为 539 nm,表观摩尔吸光系数为 1.55×105 L·mol-1·cm-1.锆(Ⅳ)的质量浓度在 0~0.32 mg/L 范围内服从比尔定律.方法已用于铝合金中微量锆的测定. 相似文献
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非离子表面活性剂胶束增溶显色反应机理的研究(Ⅱ)——非离子表面活性剂对Me2+-PAN的作用及其增溶萃取公式 总被引:1,自引:0,他引:1
本文以分光光度法研究了在TritonX-100胶束存在下,若干二价金属离子(Me2+)与1-(2-吡啶偶氮)-2-茶酚(PAN)的络合反应。导出了用聚氧乙烯型非离子表面活性剂增溶萃取Me2+-PAN螯合物的通式,并指出了利用此公式发生偏差的原因。 相似文献
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1-(5-萘酚-7-磺酸)-3-[4-(苯基偶氮)苯基]-三氮烯-溴化十六烷基三甲胺-阴离子表面活性剂的显色反应 总被引:1,自引:0,他引:1
1-(5-萘酚-7-磺酸)-3-[4-(苯基偶氮)苯基]-三氮烯(NSPAPT),在三乙醇铵介质和溴化十六烷基三甲胺(CTMAB)存在下,与阴离子表面活性剂(AS),十二烷基苯磺酸钠(DBOSO3Na)、十二烷基磺酸钠(DOSO3Na)、十二烷基硫酸钠(DSO4Na)分别形成1∶2紫红色配合物,配合物最大吸收峰位于598 nm,此方法应用于水样中微量阴离子表面活性剂的分析,所得结果的RSD均小于2%,且与亚甲基蓝光度法的测定结果相符。 相似文献
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1-(5-萘酚-7-磺酸)-3-[4-(苯基偶氮)苯基]-三氮烯-溴化十六烷基吡啶-阴离子表面活性剂显色反应研究 总被引:6,自引:0,他引:6
合成了新试剂1 (5 萘酚 7 磺酸) 3 [4 (苯基偶氮)苯基] 三氮烯(NASA PAPT)。研究了在三乙醇铵介质中,阳离子表面活性剂溴化十六烷基吡啶(CPB)存在下,NASAPAPT与阴离子表面活性剂(AS)的显色反应。NASAPAPT与AS形成1∶3的紫红色络合物,络合物最大吸收位于588nm,表观摩尔吸光系数为1.06×104~1.14×104L·mol-1·cm-1。研究检测AS的新方法应用于废水分析,测定结果与经典分析结果吻合。 相似文献
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钴与2-[2-(5-溴苯并噻唑)偶氮]-5-二甲氨基苯甲酸显色反应的分光光度法研究 总被引:1,自引:0,他引:1
本文合成丁新试剂2-[2-(5-溴苯并噻唑)偶氮-5-二甲氨基苯甲酸(5-Br-BTAMB)。研究了在表面活性剂存在下它与钴的显色反应。发现 TritonX-100存在下,钴与5-Br-BTAMB在 pH6.0~8.5范围内形成稳定的蓝色配合物。其最大吸收峰位于660nm。表观摩尔吸光系数为1.22×10~5L·mol·cm~(-1)。配合物中钴与5-Br-BTAMB 的组成比为1:2.钴浓度在0~12μg/25ml 范围内呈良好的线性关系。在硫脲存在下,该方法具有良好的选择性,用于测定含钴分子筛和 V_(B12)中微量钴。结果令人满意。 相似文献
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The dissociation constant of PAOx was determined spectro-photometrically in the presence or absence of surfactants. The state of PAOx in aqueous solutions was studied by using spectro-photometric and quantum chemical methods. The tautometric equilibrium is shifted to the quinone-hydrazone form in the presence of CTMAB. 相似文献
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A. Levent Demirel Pınar Tatar Güner Bart Verbraeken Helmut Schlaad Ulrich S. Schubert Richard Hoogenboom 《Journal of Polymer Science.Polymer Physics》2016,54(7):721-729
Poly(2‐alkyl‐2‐oxazoline)s (PAOx) exhibit different crystallization behavior depending on the length of the alkyl side chain. PAOx having methyl, ethyl, or propyl side chains do not show any bulk crystallization. Crystallization in the heating cycle, that is, cold crystallization, is observed for PAOx with butyl and pentyl side chains. For PAOx with longer alkyl side chains crystallization occurs in the cooling cycle. The different crystallization behavior is attributed to the different polymer chain mobility in line with the glass transition temperature (Tg) dependency on alkyl side chain length. The decrease in chain mobility with decreasing alkyl side chain length hinders the relaxation of the polymer backbone to the thermodynamic equilibrium crystalline structure. Double melting behavior is observed for PButOx and PiPropOx which is explained by the melt‐recrystallization mechanism. Isothermal crystallization experiments of PButOx between 60 and 90 °C and PiPropOx between 90 and 150 °C show that PAOx can crystallize in bulk when enough time is given. The decrease of Tg and the corresponding increase in chain mobility at T > Tg with increasing alkyl side chain length can be attributed to an increasing distance between the polymer backbones and thus decreasing average strength of amide dipole interactions. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 721–729 相似文献
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Joachim F. R. Van Guyse Xiaowen Xu Richard Hoogenboom 《Journal of polymer science. Part A, Polymer chemistry》2019,57(24):2616-2624
The many postpolymerization modification opportunities of biocompatible poly(2‐alkyl/aryl‐2‐oxazoline)s (PAOx), such as thiol–ene/thiol–yne, azide–alkyne cycloadditions, amidation, and transesterification, are one of the most appealing features of this polymer class for its popularity in biomedicine. Inspired by recent reports on guanidine‐catalyzed transesterification and amidation reactions of methyl ester substrates, we explored the use of guanidines as a reactant for the modification of methyl ester functional PAOx, to obtain the respective acyl guanidines. The obtained acyl guanidines functional polymers display reactivity toward α‐haloketones, yielding imidazole functional PAOx. The obtained polymer structures are protonated in a broad pH range, and the acyl guanidine moiety is demonstrated to be a cleavable linker under basic conditions. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2616–2624 相似文献
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Marcel A. Boerman Harry L. Van der Laan Johan C. M. E. Bender Richard Hoogenboom John A. Jansen Sander C. Leeuwenburgh Jan C. M. Van Hest 《Journal of polymer science. Part A, Polymer chemistry》2016,54(11):1573-1582
Polymers that possess lower critical solution temperature behavior such as poly(2‐alkyl‐2‐oxazoline)s (PAOx) are interesting for their application as stimulus‐responsive materials, for example in the biomedical field. In this work, we discuss the scalable and controlled synthesis of a library of pH‐ and temperature‐sensitive 2‐n‐propyl‐2‐oxazoline P(nPropOx) based copolymers containing amine and carboxylic acid functionalized side chains by cationic ring opening polymerization and postpolymerization functionalization strategies. Using turbidimetry, we found that the cloud point temperature (CP) is strongly dependent on both the polymer concentration and the polymer charge (as a function of pH). Furthermore, we observed that the CP decreased with increasing salt concentration, whereas the CP increased linearly with increasing amount of carboxylic acid groups. Finally, turbidimetry studies in PBS‐buffer indicate that CPs of these polymers are close to body temperature at biologically relevant polymer concentrations, which demonstrates the potential of P(nPropOx) as stimulus‐responsive polymeric systems in, for example, drug delivery applications. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1573–1582 相似文献
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异氰酸苯醇和N-[2-(4,6-二甲基)-嘧啶基]-羟胺(5)反应生成1-[2-(4,6-二甲基)-嘧啶基]-1-羟基-3-苯基脲(6)。化合物(6)在三乙胺存在下和氯甲酸乙醇反应生成2-[2-(4,6-二甲基)-嘧啶基]-4-苯基-1,2,4-噁二唑烷-3,5-二酮(1)。 相似文献
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The [Au2(TeSe2)2]2- anion has been prepared from the reaction of [TeSe3]2- with AuCN in DMF in the presence of PEt3 and from the reaction of [TeSe2]2- with AuCN in DMF. Reaction of [TeSe2]2- with AuCN in DMF in the presence of PEt3 leads ultimately to the [Au2(Te2)2]2- anion. 相似文献
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Isomeric 5-, 6-, 7-hydroxyquinolines (11-13) and 5-hydroxyisoquinoline (14) gave N,C-diprotonated dications in CF(3)SO(3)H-SbF(5) superacid medium. Compounds 11, 13, 14, and 8-hydroxyquinoline (5) underwent selective ionic hydrogenation with cyclohexane in the presence of aluminum chloride. Compounds 11 and 14 condense with benzene in the presence of aluminum halides. The detailed mechanism of reactions, which involves superelectrophilic dicationic intermediates, is discussed. 相似文献
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Adel Hamed Mohamed Mandur V. N. Buyanov V. E. Zhigachev L. N. Kurkovskaya N. N. Suvorov 《Chemistry of Heterocyclic Compounds》1990,26(10):1116-1120
The reaction of nitroindoles with chlorosulfonic acid in the presence of sodium sulfate was used to synthesize 4-, 5-, 6-, and 7-nitroindole-3-sulfonyl chlorides. Under the influence of ammonia and several amines these compounds were convened to nitroindole-3-sulfonamides which were reduced with hydrazine hydrate in the presence of Raney nickel to the corresponding amines.See [1] for Communication 135.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1341–1345, October, 1990. 相似文献
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Khudobin Yu. I. Makarskaya V. M. Makarskii V. V. Kharitonov N. P. Voronkov M. G. 《Russian Chemical Bulletin》1976,25(7):1538-1540
Conclusions The conditions were found for the hydrosilylation of CH2=CHSi(OC2H5)3 with triorganylsilanes in the presence of H2PtCl6 · 6H2O in isopropanol, which assured a high yield (>90%) of the 1-(triorganylsilyl)-2-(tri-ethoxysilyl)ethanes. These conditions were used to synthesize 27 new 1-(triorganylsilyl)-2-(triethoxysilyl)-ethanes.The addition of (C2H5O)3SiH to (CH2=CHSi(CH3)3 in the presence of the same catalyst gave 1-(trimethyl-silyl)-2-(triethoxysilyl)ethane in 98.6% yield.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1622–1625, July, 1976. 相似文献