高效液相色谱法同时测定化妆品中的3种苯扎氯铵同系物

建立了采用高效液相色谱-二极管阵列检测器(HPLC-DAD)同时检测化妆品中3种苯扎氯铵同系物(n-C12H25-C9H13NCl、n-C14H29-C9H13NCl、n-C16H33-C9H13NCl)的方法。采用含0.5%甲酸的甲醇超声提取样品,以CAPCELL PAK SCX色谱柱(250 mm×4.6 mm, 5 μm)分离,流动相为40 mmol/L乙酸铵水溶液(含0.1%三乙胺,pH 4.0)和乙腈,梯度洗脱,流速1.0 mL/min,检测波长260 nm,柱温25 ℃,进样量20 μL。该方法的检出限50.0 mg/kg,定量限200.0 mg/kg,线性范围5.0～3000.0 mg/L,加标回收率92.5%～102.1%,相对标准偏差为3.81%～6.66%。结果表明,该方法快速、准确,能够同时测定化妆品中3种苯扎氯铵同系物。     

反相高效液相色谱法测定复方化学消毒剂中苯扎氯铵含量的不确定度评定

对反相高效液相色谱法测定复方化学消毒剂有效成分苯扎氯铵中正十二烷基二甲基苄基氯化氨(n-C12H25-C9H13NC l)含量的不确定度进行了评定。分析了测量不确定度的来源,如样品取样体积、样品稀释体积、标准溶液制备、标准曲线绘制和测量重复性,对各不确定度分量进行了评定。n-C12H25-C9H13NC l含量测量的扩展不确定度为5.4%。     

长链烷基二苯基膦—铑配合物催化烯烃氢甲酰化反应研究

研究了烷基二苯基膦-铑配合物RhCl(CO0(n-C8H17PPh2)2(1)和RhCl(Co)(n-C12H25PPh2)2（2）对1-辛烯氢甲酰化反应的催化性能。结果表明,配合物1比2具有更高的催化活性,而配合物2对生成正构醛的选择性更好;当催化剂浓度或膦/铑比增加时,配合物2催化成正构醛的选择性呈下降趋势,显示出与以PPh3为配体时的不同的性能。     

不同阴/阳离子表面活性剂复配体系的缔合结构研究

测定了十二烷基磺酸钠(AS)/十六烷基三甲基溴化铵(CTAB)/正丁醇(n-C4H9OH)/正庚烷(n-C7H16)/水(H2O),十二烷基硫酸钠(SDS)/十六烷基三甲基溴化铵(CTAB)/正丁醇(n-C4H9OH)/正庚烷(n-C7H16)/水(H2O)体系的微乳液正四面体相图,并用电导法划分了AS/CTAB/n-C4H9OH/n-C7H16/H2O体系微乳液的结构(W/O,B.C.和O/W);同时研究AS/CTAB/n-C4H9OH/n-C7H16/H2O/盐类(NaCl,CaCl2或AlCl3)体系和SDS/CTAB/n-C4H9OH/n-C7H16/H2O/盐类(NaCl,CaCl2或AlCl3)体系形成中相微乳的盐宽,从中得出上述两体系中相微乳的盐宽随盐类阳离子价态的增大而的规律。     

辅酶B_(12)模型化合物的研究(V)RCo(Salen)L配合物Co—C键断裂的动力学

运用光度法研究了RCo(Salen)L配合物在甲醇中热分解反应动力学;测定了Co—C键断裂的速率常数及活化能,得到表观速率常数顺序为i-C3H7>i-C4H9>n-C4H9>n-C3H7>C2H5,活化能顺序为i-C3H7相似文献   

液体的饱和蒸气压与内压

本文用统计热力学的方法, 建立了液体饱和蒸气压, 与内压间的关系式。对C6H6、CCl4、cy-C6H12、C(CH3)4、n-C6H14和(CH3)2CO等六种液体的检验结果表明, 上述关系式能适用于广阔的温度范围。     

三苯基 合二钼四正丁基铵盐的合成和鉴定

在有机溶剂中使多种单芳基 酸与钼酸钠进行反应, 合成了中间体ArSbO(OH)2、Ar2SbCl3和Ar3SbI2, 发现只有后者可与[(n-C4H9)4N]2MoO4反应, 从而制得一种无色透明晶体[(n-C4H9)4N]2[(C6H5)3Sb(MoO4)2]·3H2O。     

三苯基 合二钼四正丁基铵盐的合成和鉴定

在有机溶剂中使多种单芳基 酸与钼酸钠进行反应, 合成了中间体ArSbO(OH)2、Ar2SbCl3和Ar3SbI2, 发现只有后者可与[(n-C4H9)4N]2MoO4反应, 从而制得一种无色透明晶体[(n-C4H9)4N]2[(C6H5)3Sb(MoO4)2]·3H2O。     

Degradation Method for Preparing Organo-Arsenic and-Antimony Polytungstates and Comparative Study of Corresponding Polymolybdates

In repeating and extending the syntheses of organo-arsenic polytungstates,we found that the "Degradation Method",taking sodium metatungstate as the starting material,was much more profita-ble.The known compound (CN3H6)5[(C6H5As)2W6O25H]2H2O(1) was read-ily reproduced with a high yield.A new compound (CN3H6)6[(p-OH,m-NO2C6H3As)2W6O25](2) was likewise synthesized.This "Degradation Method" using the reaction of sodium metatungstate with organo-anti-monate led to the isolation of four compounds with definite composition although amorphous in appearance.The preparations of organo-arsenic polymolybdates and organo-antimony polymolybdates were also studied and six new organo-arsenic polymolybdates were isolated: (CN3H6)5[(C6H5As)2MoO25H]H2O(3),(CN3H6)4[(n-C3H7As)2Mo5O21]2H O (4),(CNH)4[(n-C3H7As)2Mo6O24](5),Cs2[(CH3)2AsMo4O15H](6),相似文献   

两种烷基碘化物分子理论研究及其发射谱测量

利用密度泛函理论(DFT)的B3LYP方法, 对烷基碘化物分子C2H2F3I和n-C3H4F3I的C—I解离势能曲线进行了理论计算, 并采用B3LYP方法和MPn(n=2, 3, 4)方法精确计算了C—I键解离能. 解离能计算进行了零点振动能(ZPVE)校正, 并运用完全均衡校正法对基函数重叠误差(BSSE)进行校正. 利用微波放电激励方法, 对C2H2F3I和n-C3H4F3I的发射谱进行观测. 实验结果表明, 通过微波放电激励这两种分子, 均可产生1315 nm发射谱, 说明利用微波放电可使C2H2F3I和n-C3H4F3I分子的C—I键解离, 从而产生碘原子.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.