共查询到20条相似文献,搜索用时 125 毫秒
1.
用偶联剂3-(环氧丙氧基)丙基三甲氧基硅烷(GPTMS)将手性螺旋聚3-(9-烷基芴-9-基)-1,2-环氧丙烷键合到硅胶表面上,制备成高效液相色谱手性固定相。将该类手性固定相应用于拆分外消旋体。研究发现,在该类手性固定相中,以聚3-(9-乙基-9-芴基)-1,2-环氧丙烷键合硅胶手性固定相拆分效果为最佳。而且,这类手性固定相应用于高效液相色谱,解决了以往单手性螺旋的聚甲基丙烯酸酯类作为手性固定相一直存在的溶剂问题。 相似文献
2.
3.
使用1,3,5-三甲醛间苯三酚(Tp)、单体3,3′-二硝基联苯胺(DNB)合成了TpBD(NH2)2,并采用后合成修饰策略对该材料进行手性修饰,网包法将其固载到球型硅胶上,得到手性衍生物固定相材料。利用X射线衍射、红外光谱、圆二色谱、热重分析、氮吸附-脱附和扫描电镜对该材料进行表征。实验结果表明材料空间结构和热稳定性良好。使用该材料的手性固定相制备的色谱柱已成功拆分二苯基乙醇酮、华法林、N-(3,5-二硝基苯甲酰)-L-亮氨酸、1-苯乙醇、2-甲基戊酸甲酯、2-乙基己酸、1,2-环氧丁烷、环氧溴丙烷、3-氯-2-丁酮、2-甲基戊醛、3-羟基丁酸乙酯、异丙基缩水甘油醚、乳酸乙酯、1-(1-萘基)乙胺、γ-辛内酯。根据对拆分温度的探究,得到了该色谱柱的最佳拆分温度。选用华法林作为分析对象,评价色谱柱的性能,表明该柱具有良好的重复性,可用作高效液相色谱柱的固定相。 相似文献
4.
5.
自制了3种键合型直链淀粉苯基氨基甲酸酯类(苯基氨基甲酸酯IAT、3-氯苯基氨基甲酸酯IAC、3,5-二甲基苯基氨基甲酸酯IAD)手性固定相,比较了3种固定相对6种手性化合物的手性识别能力,同时也将商品柱Chiralcel OD-H、Chiralcel AD-H对6种手性化合物的拆分结果进行了比较。实验结果表明:所合成的键合型手性固定相对样品托儿格碱、2-羟基-3-(2-萘氧基)丙基-2',3'-二甲基苯基硒醚和戊唑醇表现出更好的手性识别能力,并且直链淀粉衍生物苯环上引入吸电子基团或给电子基团对固定相手性识别能力均有明显的影响。 相似文献
6.
先采用3-氨丙基三乙氧基硅烷、三甲基氯硅烷、N-辛基三甲氧基硅烷等硅烷偶联剂对MCM-41介孔材料进行氨基和不同长度的烷基链后嫁接处理,然后将天然抗氧化剂α-生育酚负载于表面修饰前后的MCM-41,再与低密度聚乙烯(LDPE)熔融共混制备抗氧化活性食品包装膜。对α-生育酚/MCM-41组装体及活性膜的性能进行表征分析,研究表面修饰前后不同表面基团对活性膜微观形貌、结晶性的影响;此外,通过迁移试验研究MCM-41表面修饰对薄膜控释性能的影响,开发具有不同控释行为的抗氧化活性薄膜。结果表明,疏水性基团的嫁接提高了组装体在非极性聚合物基质中分布的均一性;由于MCM-41表面嫁接了有机官能团,聚合物的结晶度得到提高;烷基链长度增加,α-生育酚在活性膜中的释放速率减缓,嫁接氨丙基的MCM-41对α-生育酚的缓释效果最明显,释放速率相较于未嫁接以前降低了约71%。 相似文献
7.
8.
采用十六烷基二甲基叔胺和十八烷基二甲基叔胺分别与盐酸、环氧氯丙烷反应,制备得中间产物N-(3-氯-2-羟基)丙基-N,N-二甲基十六烷基氯化铵和N-(3-氯-2-羟基)丙基-N,N-二甲基十八烷基氯化铵。2种中间产物在碳酸钠催化下先后与乙二胺反应生成一种含长亲水链非对称阳离子双子表面活性剂(16-X-18)。采用IR和~1H NMR对中间体和产物进行表征,采用电导率法研究了所制备的表面活性剂的表面活性。结果表明,所制备的非对称阳离子双子表面活性剂的Krafft点低于0℃,cmc在25℃时为2.935×10~(-5)mol/L,反离子结合度随温度的上升而降低。 相似文献
9.
采用一步键合法合成了β-环糊精基氧化钨毛细管电色谱整体柱,考察了制备整体柱的主要影响因素,获得最佳制柱条件为:功能单体双(6-O-丁烯二酸单酯)-β-环糊精(CPD-β-CD)与EDMA物质的量比为0.12∶0.08,修饰纳米氧化钨的质量0.30 g,水浴温度40℃,聚合时间13 h。同时对整体柱进行了表征和评价,制备的整体柱有较均匀孔径的网状结构,固定相中修饰纳米氧化钨的含量达到16.6%,整体柱有良好的重现性和稳定性,同时具备较好的手性拆分能力。在最佳电色谱条件下,应用整体柱对美托洛尔、阿替洛尔和索他洛尔对映体进行拆分,均达到基线分离。 相似文献
10.
当今社会对单一对映体的需求越来越大,由于手性表面活性剂具有区域选择性、手性催化能力及手性识别能力,因而在手性合成、手性识别及手性拆分中的应用也越来越受封重视。文章综述了近年来手性表面活性剂在不对称催化、乎性识剐及手性拆分中的应用。 相似文献
11.
12.
To investigate the stereo coordination effect on the optical resolution, chiral monomer (+)‐5‐oxobornyl methacrylate (OBMA) was synthesized and then polymerized under various conditions. In this work, optical resolution was carried out in the presence of chiral polymers having (+)‐5‐oxobornyl moieties as chiral stationary phase (CSP) for high‐performance liquid chromatography (HPLC). Chiral polymer was immobilized on the surface of hydrophobic silica gel, and the chiral recognition ability of the chiral polymers was investigated. Effects of operation temperature and eluent flow rate on the chromatographic resolutions were investigated. The results of optical resolution were compared with those observed in our previous paper using chiral polymers (CSP‐1 and CSP‐2) having 2,3‐dihydroxybornyl moieties as chiral stationary phases. It was found that the recognition ability of poly(OBMA) is greater than those of CSP‐1 and CSP‐2. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 677–682, 1999 相似文献
13.
14.
The molecular imprinting method was applied for synthesizing gels with a chiral helical cavity using various bifunctional vinyl monomers, such as α-(benzyloxymethyl)acrylic acid derivatives as a monomer, and one-handed helical (+)-poly(diphenyl-2-pyridylmethyl methacrylate) as a template. The chiral gels were almost quantitatively prepared after removal of the template polymer by hydrolysis of the ester groups. The obtained gels exhibited chiral resolution powers toward various racemates, such as trans-stilbene oxide and Tröger's base, and the substituents on the phenyl group of the monomer significantly affected the recognition ability. The observed separation factors were higher than those of the gels prepared from the mono-functional vinyl monomer, methacrylic acid. 相似文献
15.
冠醚类化合物选择性识别金属阳离子。在大量调研文献的基础上,设计合成了冠醚类化合物,通过对蒽醌化合物进行修饰,合成了冠醚环和吡唑啉,将产物进行了荧光测定,发现该化合物能够很好的识别铜离子和铁离子。对该化合物进行了进一步的干扰离子测定,发现其基本不受影响,得到了较好的识别效果。 相似文献
16.
Qian Miao Hui Huang Xiaobo Huang Ying Xu LiLi Zong Yixiang Cheng 《Polymer International》2010,59(5):712-718
A chiral conjugated polymer can be obtained by the polymerization of (S)‐6,6′‐dibromo‐2,2′‐binaphtho‐20‐crown‐6 and 1,4‐divinyl‐2,5‐dibutoxybenzene via a palladium‐catalyzed Heck cross‐coupling reaction. The chiral conjugated polymer shows strong green‐blue fluorescence. The responsive properties of the chiral polymer to metal ions were investigated using fluorescence and UV‐visible absorption spectra. K+, Pb2+, Cd2+ and Ba2+ enhance the fluorescence of the polymer; in contrast, Hg2+ causes effective quenching of the fluorescence of the polymer. The obvious influences on the fluorescence indicate that the 2,2′‐binaphtho‐20‐crown‐6 moiety plays an important role in fluorescence recognition for Hg2+ due to the effective photo‐induced electron transfer or charge transfer between the conjugated polymer backbone and the receptor ions. The responsive properties of the polymer to metal ions show that the chiral conjugated polymer incorporating 2,2′‐binaphtho‐20‐crown‐6 moieties in the main‐chain backbone as recognition sites can act as an excellent fluorescent probe for the sensitive detection of Hg2+. Copyright © 2010 Society of Chemical Industry 相似文献
17.
18.
We describe a method to fabricate silica gel particles coated with a monolayer of pristine single-walled carbon nanotubes (SWCNTs). SWCNTs dissolved in 1-methyl-2-pyrrolidinone (NMP) are mixed with amino-functionalized silica gels having different diameters. Strong interaction between the amino group and the SWCNT surfaces induces the adsorption of the SWCNTs on the silica, while the stable solvation in NMP hampers further adsorption of the tubes. This approach enables the production of a homogeneous, nondestructive and high-yield coating of the SWCNTs onto the silica surfaces, especially for larger sphere with a diameter over 1 μm. The density and bundling degree of the SWCNTs on the silica gel surfaces are finely controlled by simply changing the ratios of the SWCNTs to the silica gels as well as the SWCNT concentrations. We also describe the coating of the silica gels with metallic SWCNTs. The SWCNT-coated silica gels are useful for a wide range of materials, such as the stationary phase for liquid chromatography and catalyst supporting materials. 相似文献
19.
介绍了冠醚化学的产生发展及应用,详细综述了:①新型冠醚的合成及其对阳离子的选择性识别作用;②新型双冠醚配体及其稀土过渡金属配合物的合成;③新型氮杂冠醚的合成及应用。并对冠醚化学的发展进行了展望。 相似文献
20.
狼毒大戟水提取物中化学成分的分离与鉴定 总被引:8,自引:1,他引:7
为了研究狼毒大戟水提取物的化学成分,依次用乙醚、丙酮等不同溶剂对狼毒大戟水提取物进行了萃取,乙醚萃取物真空浓缩后用硅胶柱色谱分离,不同溶剂洗脱,分离得到了5个化合物,经质谱、红外和核磁测定,证明3个为萜类,2个为苯乙酮类。石油醚洗脱得到β-香树脂醇乙酸酯(-βamyrin acetate);V(石油醚)∶V(乙醚)=9∶1洗脱得到Jolk inolide A;氯仿洗脱得到3,3′-二乙酰基-4,4′-二甲氧基-2,2,′6,6′-四羟基二苯甲烷;V(氯仿)∶V(乙醚)=8∶1洗脱得到2,4-二羟基-6-甲氧基-3-甲基苯乙酮(狼毒乙素)和Jolk inolide B。 相似文献