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1.
用INDO系列方法研究了C60的哌嗪衍生物C60N2(C2H4)2的结构。结果表明[6,6],异构体具有C2v对称性[6,5],异构体具有Cs对称性,前者能量较低。以优化构型为基础,计算两种加成产物的UV谱,结果表明,[6,6]异构体的特征吸收与实验值相符,同时对[6,5]异构体的UV谱进行理论预测,对电子跃迁进行了理论指认,并分析了光谱红移的原因。  相似文献   

2.
水杨醛苯腙与铜荧光反应的研究及其应用   总被引:6,自引:0,他引:6  
水杨醛苯腙与铜荧光反应的研究及其应用江崇球,唐波,傅红燕,曹红,张晓刚(山东师范大学化学系,济南,250014)关键词铜,水杨醛苯腙,荧光分析胺类试剂是一类理想的荧光分析试剂[1],用其测定Al3+[2]、Ga3+[3]、Zn2+[4]已显示出其灵敏...  相似文献   

3.
纳米SnO2的制备   总被引:18,自引:0,他引:18  
SnO2在陶瓷、气敏半导体材料及催化剂等方面被广泛应用[1].纳米级的SnO2因具有明显的表面效应而受到关注,其制备方法也受到重视[2].纳米SnO2的制备方法较多,有沉淀法[2]、水热法[3,4]、溶胶-凝胶法[5]、火焰合成法[6]等.然而要制备...  相似文献   

4.
由于开放骨架结构的金属酸盐具有潜在的应用前景,因此合成具有开放骨架结构的金属磷酸盐一直是研究的热点[1~3]. 自从第一个具有微孔结构的磷酸铝[4]被报道以来,许多其它具有开放骨架结构的金属磷酸盐被合成出来[5~14]. 然而有关磷酸镍研究的报道很少,仅有几个具有开放骨架结构的磷酸镍[15,16]和一些碱金属的磷酸镍[17~19](大部分是通过固相法合成的). 本文通过水热法合成了一个新的具有层状结构的磷酸镍[Ni3(PO4)2·8H2O],并通过X射线单晶衍射测定了其结构,其结构中包含共角的多面体连接成的四元环和八元环.  相似文献   

5.
本文合成了四种新的单取代氨基酸四苯基卟啉锌配合物Zn[Val-TPP]、Zn[Glu-TPP]、Zn[Tyr-TPP]和Zn[Trp-TPP]。通过化学分析和元素分析确定了配合物的组成,研究了它们的紫外、红外、荧光和激光拉曼光谱。  相似文献   

6.
1990年Kratschmer[1,2]等人实现了C60和C70的宏观量制备后,有关fullerene的化学研究迅速展开[3-5].业已发现C60具有极为丰富的化学性质.在对C60化学性质的认识过程中,气相离子化学一直起着重要的作用[6].Roth等人[7]在ICR质谱仪中,制得了C60外部键合金属的衍生物C60M+;Caldwell及合作者[8]在质谱仪上,利用高动能的C60与轻气体(He,Ne,H2,D2)碰撞,得到了笼内包含轻气体原子的C60;Bohme[9,10]等人在流动后辉光质谱仪上,系统地研究了C60的单、双、三电荷离子与多种有机物的反应,获得了相应的C60加合…  相似文献   

7.
活性亚甲基化合物的电解氧化偶联反应   总被引:6,自引:0,他引:6  
在有机合成上,活性氢化合物的偶联是形成碳-碳键的重要方法之一[1,2]。其偶联一般用化学方法在强碱的作用下得到碳负离子,继而用弱氧化剂I2[3]、CuBr2[4]、AgNO3[5]等将碳负离子变成游离基偶联而成。1964年,Toshihiko报道了在...  相似文献   

8.
热敏性高分子包裹的磁性微球的合成   总被引:14,自引:3,他引:14  
磁性高分子微球由于其在外加磁场作用下简单、快速易行的磁分离特性,其在细胞分离、固定化酶、靶向药物等领域的应用研究日益活跃,并显示出较好的应用前景[1].有关文献报道了制备磁性微球的不同方法[2].N 异丙基丙烯酰胺(N isopropylacryla...  相似文献   

9.
极谱法研究大黄酸-环糊精包结物   总被引:7,自引:0,他引:7  
李向军 《电化学》1999,5(3):348-351
大黄酸是中药大黄中的有效成份,具有抗菌、止咳和抗肿瘤作用.近年来对大黄酸的研究日渐深入,其应用日趋广泛.由于其水溶性低,且对胃肠有刺激作用,导致生物利用度低,应用受到了限制.环糊精是由葡萄糖基以1,4糖甘键连成的中空筒状化合物,具有疏水的内腔和亲水的外表面,可有效地包结各种客体分子,从而能改变客体分子的状态、稳定性、溶解度等理化特性[1],文献曾经报道β_环糊精与药物形成包结物,可提高溶解度[2]及降低对胃的刺激性[3].近来用电化学方法研究环糊精的报道日渐增多[4,5].本文用极谱法研究了β_…  相似文献   

10.
含高氯酸锂的IPN固体电解质研究   总被引:1,自引:0,他引:1  
高分子固体电解质(polymericsolidelec-trolyte)由于其潜在的应用价值,人们对它进行了广泛的研究[1]。目前,主要围绕如何提高室温电导率和机械强度进行研究[2]。在所有这些研究中,利用环氧树脂(ER)与低分子量聚乙二醇(PEG)...  相似文献   

11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.  相似文献   

12.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.  相似文献   

16.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

17.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

18.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

19.
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%).  相似文献   

20.
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.  相似文献   

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