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多羟基化合物水溶液渗透系数的测定   总被引:1,自引:0,他引:1  
The determination of the osmotic coefficients of the aqueous solution of polyhydroxylated compounds such as glycol, glycerol, sucrose and glucose by Vapour Pressure Osmometry at 313, 323 and 333K was carried out over the concentration range of 0.0-2.1mol﹒kg-1 and 0.0-2.0 mol﹒kg-1 respectively. By using a linear least-square fitting routine, the osmotic coefficients were fitted by a simple polynomial equation, It was found that the relation between the experimental results of molal osmotic coefficients Φ and the mass molal concentration of the solution m are in agreement with that from the polynomial fitting at different temperature. Factors which influence the osmotic coefficient such as the number of hydroxyl of polyhydroxylated compounds or the molecule weight of the solute molecules should be further studied, this work will also contribute to the studies of other thermodynamical properties of the aqueous solution of polyhydroxylated compound.  相似文献   

3.
对烯丙基作为核苷糖环上羟基保护基进行了研究.烯丙基可用于核糖羟基的保护,用PdCl2可脱除核苷糖环上烯丙基,保护及脱保护都很简便.PdCl2还可脱除核苷糖环5'-OH常用的保护基--对甲氧基三苯甲基及二对甲氧基三苯甲基.控制适当的条件,PdCl2既能够选择性地脱除对甲氧基三苯甲基或二对甲氧基三苯甲基,又可同时脱除保护糖环羟基的烯丙基.  相似文献   

4.
硼酸与多羟基化合物的反应及硼选择性树脂   总被引:7,自引:0,他引:7  
本文综述了硼酸与多羟基化合物的反应,并系统介绍了硼选择性树脂的发展,引用文献57篇。  相似文献   

5.
通过三茂基镧系化合物Cp_3Ln(Cp=C_5H_5;Ln=Sm,Dy,Ho)与8-羟基喹啉反应(HL),合成了3种新的镧系金属有机化合物,通式为Cp_2LnL(Ln=Sm,Dy,Ho)。经元素分析、红外光谱、X光电子能谱、质谱及分子量测定,推断化合物具有二聚体结构,分子内存在通过喹啉氮原子和氧原子与金属配位而形成的五元螯合环。对化合物的热稳定性进行了研究和比较,发现化合物Cp_2SmL对热不稳定,在180℃以上分解为Cp_3Sm和SmL_3。  相似文献   

6.
在不同条件下制得三种类型的希土与3-磺基-4-羟基香豆素(H2SHC)化合物,元素分析确定了它们的组成分别为Ln(HSHC)3·9H2(Ln=La,Pr,Nd,Gd,Dy,Er,Yb,Y),Ln2(SHC)3.nH2O(Ln:La,Pr,Nd,Sm,Gd,N:4或6)和Na3Ln(SHC)3·H2O(Ln=Er,Yb).并通过它们的摩尔电导戌重,溶解度,红外光谱和电子吸收光谱对各种化合物进行了结构和性质的研究。  相似文献   

7.
王来新  张礼和 《有机化学》1994,14(3):242-258
近几年来, RNA的化学合成有了较大进展, 本文讨论了RNA化学合成过程中的保护基问题,着重介绍了核糖核苷的2'-和3'-位羟基的选择性保护方法。  相似文献   

8.
硼酸与多羟基化合物配位反应的热化学研究   总被引:3,自引:0,他引:3  
用量热法在298.2 K测定了B(OH)~-_4与多羟基化合物的反应焓。计算了硼酸与多羟基化合物的配位焓和配离子的标准生成焓。根据配位焓确定了B(OH)~-_4与甘露醇、山梨醇、丙三醇、葡萄糖等多羟基化合物配位反应的配位数,B(OH)~-_4与甘露醇、山梨醇的配位数是2;与丙三醇、葡萄糖的配位数是1.  相似文献   

9.
胍基化合物在分子识别中的应用   总被引:1,自引:0,他引:1  
对胍基化合物的结构、物理化学性质进行了简要说明,重点综述了胍基化合物的分子识别功能在主客体化学中的应用和最新研究进展。参考文献49篇。  相似文献   

10.
本文合成了两个新的对空气极敏感的希土烯丙基化合物,由无水希土氯化物与希丙基锂在四氢呋喃—乙醚中反应制得。产物经元素分析、红外光谱等确定其组成为:Li2Ln(C3H5)5·3Dioxane(Ln=Gd,Lu)。  相似文献   

11.
<正> A novel polymer-bound 1,2-diol, 3-polystyrylsulfonyl-1,2-propanediol (6) had been prepared by the reaction of sodium polystyrylsulfinate with allyl bromide, followed by oxidation and. hydrolysis or directly with 3-chloro-1,2-propanediol in the presence of a phase transfer catalyst, n-tetrabutylammonium iodide. The capacity of resin 6 for terephthaidehyde reached 1.43 mmol/g. The aldehydic groups attached to polymer 6 reacted with hydroxylamine hydrochloride or reduced by sodium borohydride giving p-formylbenzaldoxime (yield: 89%)and p-formyl-benzalcohol (yield: 734%), respectively. The high yields of these polymer-supported reactions showed that the polymer 6 possessed the effective isolation of its reactive sites.  相似文献   

12.
Abstract

Reaction of dimethyl benzoylphosphonate with hydrazine hydrate gave exclusively benzhydrazide. Reaction of methyl lithium benzoylphosphonate with hydrazine hydrate gave the corresponding hydrazone (3) as a 65:35 mixture of E and Z isomers. Reaction of hydrazine hydrate with diisopropyl 4phthalimidobutanoylphosphonate gave mainly products resulting from nucleophilic attack of hydrazine on the carbonyl of the acylphosphonate and only a small percentage of phthalhydrazide. From our results it appears that the N-phthaloyl protecting group is not suitable for the transient protection of amino groups during attempts to synthesize aminoacylphosphonates.  相似文献   

13.
Reactions of 2-dichloromethylene-1,3-dioxolane (2) with acetal protected sugar derivatives in neutral media gave 2-dichloromethyl-1,3-dioxolan-2-yl orthoesters. These orthoesters are readily hydrolysed under mild acidic conditions offering a new method for the preparation of readily removable protecting groups. This strategy was realised in the preparation of 6-O-acetyl-3,5-di-O-methyl-1,2-O-isopropylidene-α-d-glucofuranose.  相似文献   

14.
A use of sulfonate ester as a linker in synthesis of w-aminoalkanols was reporte.Diols were tethered onto polystyryl sulfonyl chloride resin,yielding sulfonate resins(2).After cleaved by diethyl amine,diisopropylamine and propylamine respectively,three w-aminoalkanlos were obtained.  相似文献   

15.
1. INTRODUCTIONIn recent years, solid phase organic synthesis (SPOS) has been increasingly used in the synthesis of small organic molecules [1]. The rapid development of SPOS brings with it the need for expanding a variety of linkers in order to accommodate new synthesis methods[2], and especially in the case of combinatorial chemistry, to allow additional diversity elements.Recently, Rueter and coworkers reported the use of a sulfonate ester as a linker in SPOS [3,4] and the compati…  相似文献   

16.
《合成通讯》2013,43(17):2695-2704
ABSTRACT

A sulfonic acid isopropyl ester protecting group methodology was developed that allowed for the efficient seven step synthesis of multigram amounts of an arylsulfonic acid-based follicle stimulating hormone antagonist.  相似文献   

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18.
Abstract—Flavins, flavin nucleotides and selected flavoproteins have been compared in a reaction using blue light. in which plastocyanin is oxidized as the flavin is photoreduced. Per unit of light absorbed. flavin mononucleotide is more effective than flavin adenine dinucleotide, ribotlavin or lumiflavin. Of the flavoproteins tested, diaphorase from Clostridium kluyveri was most effective, but was less active than free flavin mononucleotide. The oxidation of plastocyanin requires aerobic conditions. and appears to be mediated by the production of singlet oxygen when the flavin is irradiated.  相似文献   

19.
评述了多元络合物在生物成分分析中的应用近况,内容包括用吸光光度、荧光光度、化学发光、瑞利光散射和电化学分析方法,对黄酮类化合物、茶多酚、维生素C、氨基酸、蛋白质、核酸和酶等生物成分的测定与研究,引用文献41篇。  相似文献   

20.
Abstract— Exploratory experiments using simulated conditions indicate that the terpene, (+)-limonene can serve to detect O2(1Δg) in polluted atmospheres. 1O2 attack on limonene results in the formation of specific oxidation products in a specific distribution; quantitative identification of these products is a highly specific test for 1O2.  相似文献   

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