首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
β-环糊精-烟酸超分子体系的合成、表征及结构   总被引:6,自引:0,他引:6  
周卫红  王瑾玲  缪方明 《化学学报》2001,59(7):1135-1138
合成了β-环糊精-烟酸超分子体系,用差热分析和核磁共振等方法进行了表征,利用X射线衍射数据确定了其结构。分子式为(C42H70O35)·(C6O2H5N)·7.53(H2O)·0.73(CH3OH),属单斜晶系P21空间群,a=1.51616(4),b=1.02642(4),c=2.09296(3)nm,β=110.209(2)°,V=3.05659(3)nm^3。最小二乘修正结果,R=0.0576。晶体结构测定结果表明,这个超分子体系是属于较少见的“浅包结”方式,客体位于环糊精主体窄口端,伯羟基的O(66),O(67)原子及大多数水分子处于无序状态,大量存在的分子内和分子间氢键,形成了一个密集的氢键网络。氢键是超分子体系形成及稳定存在的主要驱动力。  相似文献   

2.
牛磺酸缩2-吡啶甲醛席夫碱,3,5-二羟基苯甲酸与醋酸铜在50%甲醇中反应合成了铜(Ⅱ)-牛磺酸缩2-吡啶甲醛席夫碱-3,5-二羟基苯甲酸三元配合物{[Cu(C8H9N2O3S)(C7H6O4).(H2O)2].2H2O(1)},其结构经IR,元素分析和X-射线单晶衍射法表征。1属三斜晶系,空间群P-1,晶胞参数a=7.066(2),b=11.891(4),c=12.859(4),α=104.034(14)°,β=96.884(13),°γ=99.053(10)°,V=1020.9(6)3,Z=2,Dc=1.633 g.cm-3,μ=1.233 mm-1,F(000)=518,R1=0.1108,wR2=0.322。1的中心铜离子与席夫碱配体的两个N原子,3,5-二羟基苯甲酸羧酸根上一个O原子以及两个水分子的O原子配位,形成一个五配位的四方锥结构。由结晶水分子,没参与配位的磺酸基氧,配位水分子间形成的氢键以及吡啶环、苯环间的π┈π相互作用,使1分子堆积成三维超分子网状结构,稳定了整个晶体结构。  相似文献   

3.
水合5-(4-羟基苯酚)四氮唑的溶剂热合成及其晶体结构   总被引:2,自引:0,他引:2  
以4-羟基苯氰为原料,用溶剂热法合成了水合5-(4-羟基苯酚)四氮唑晶体[(C7H6N4O)·1.5H2O,1],其结构经1H NMR,IR,元素分析及X-单晶衍射表征.1属单斜晶系,C2/c空间群,晶胞参数:a=1.487 2(3) nm,b=0.992 3(2) nm,c=1.304 8(2) nm,β=113.724(3)°,V=1.762 8(5) nm3,Dc=1.365 g*cm-3,F(000)=760,Z=8,μ(MoKα)=0.104 mm-1,R1=0.050 5,wR2=0.117 6.1中存在强烈的分子间氢键和π-π堆积作用.  相似文献   

4.
TANG Wu  SHI  De-Qing 《结构化学》2010,(5):769-773
The crystal structure of the title compound (C25H28N5O5P,Mr=509.49) has been determined by single-crystal X-ray diffraction.The crystal is of monoclinic,space group P21/c with a=13.0726(4),b=13.4513(4),c=15.103(1),β=93.650(1)°,V=2650.29(14)3,Z=4,Dc= 1.277 g/cm3,F(000)=1072,μ(MoKα)=0.147 mm-1,the final R=0.0748 and wR=0.1956 for 3186 observed reflections (I 2σ(I)).The fused triazolopyrimidine system ring is coplanar,the dihedral angles between the triazolopyrimidine and C(1)-C(3)-C(5) phenyl,the triazolopyrimidine and C(17)-C(19)-C(21) phenyl,and the two phenyl rings are 66.87,58.79 and 80.11o,respectively.Intramolecular N(5)-H(5A)…O(3) and intermolecular C(2)-H(2)…N(4),C(18)-H(18)…O(3),C(19)-H(19)…O(2) and C(24)-H(24C)…N(4) hydrogen bonds together with C-H…π interactions contribute to the stability of the structure and result in a three-dimensional framework.The preliminary bioassay indicates that the title compound exhibits moderate herbicidal activity against dicotyledonous plants (Brassica campestris L) at the concentration of 100 mg/L.  相似文献   

5.
由水杨醛与水合肼反应生成希夫碱N ,N′ 双水杨醛缩连氮 ,并用溶液法生长其单晶。X 射线单晶结构分析表明 ,此晶体属于单斜晶系 ,P2 ( 1) /n空间群 ,晶胞参数为 :a =8.4 97( 4 ) ,b =6 .2 90 ( 3) ,c =11.789( 5 ) ,β=10 7.874 ( 7)° ,V =5 99.6 ( 4 ) 3 ,Z =2 ,Dc =1.331g·cm-3 ,F ( 0 0 0 ) =2 5 2 ,结构偏离因子R =0 .0 4 6 9,wR2 =0 .110 8。晶体中一个分子羟基上的氧原子与另一个分子中 -CH =N -上的氢原子之间形成分子间氢键 (O┄H -C)。  相似文献   

6.
通过水热合成方法合成了一个双钒帽Keggin型多酸超分子化合物(C7H8NO2)2(C3H4N2)4[H7PV12O40(VO)2].8H2O,采用IR、单晶X-射线衍射法、TG/DTG和循环伏安法对标题化合物进行结构和性质研究。结构解析表明,化合物属于三斜晶系,P-1空间群,晶胞参数a=1.15597(3)nm,b=1.22209(3)nm,c=1.32804(2)nm.α=67.225(5)°,β=66.618(5)°,γ=75.374(6)°,V=1.576.91(6)nm3,Dc=2.204 g/cm3,Z=1,F(000)=1027,u=2.213 mm-1,S=1.073,Rint=0.0278,最终偏差因子R=0.0510和wR=0.1306。该化合物通过氢键作用形成3D超分子结构,咪唑分子填充于氢键形成的空隙中。  相似文献   

7.
利用Nd(NO)36H2O和3-(3-吡啶基)丙烯酸在水热反应条件下反应,合成了一种新型一维链状配位聚合物[Nd(C8H7NO2)3(H2O)]n。用元素分析、IR和TGA-DTA进行了表征, 并用X-射线衍射法测定了晶体结构。结果表明,该晶体属三斜晶系,(分子式C24H23N3O7Nd),P空间群,晶胞参数为a = 6.275(2),b = 12.757(4), c = 15.714(5) 牛琣 = 111.966(5), b = 90.338(6),g = 94.960(6),V = 1161.2(7) ?,Z = 2,Dc = 1.735 g/cm3,m = 2.286 mm-1,Mr = 606.67, F(000) = 602,R = 0.0355, wR = 0.0757。通过3-(3-吡啶基)丙烯酸配体羧基氧原子桥联形成一维链状结构,同时链与链通过氢键及-相互作用形成了三维的网络结构。  相似文献   

8.
在水和乙醇溶剂中,通过Cu(Ⅱ),Fe(Ⅲ)和Fe(Ⅱ)与2,2'-联咪唑协同作用,构筑了四种新的超分子配合物[Cu(H2biim)(gly)(H2O)]Cl·H2O(1),[Cu(H2biim)(C3H2O4)(H2O)]·1.5H2O(2),[Fe2(μ-O)(H2biim)4(H2O)2](NO3)4·C2H5OH(3)和[Fe(H2biim)3]SO4(4)(H2biim=2,2'-联咪唑;gly-=甘氨酸根;C3H2O24-=丙二酸根).并通过元素分析,红外光谱和X射线单晶衍射对其组成、结构和谱学性质进行研究.H2biim配体,丙二酸根和甘氨酸根三种配体都采用了双齿螯合方式与金属离子配位.配合物1~4中,通过H2biim配体的N-H键与阴离子、水分子和溶剂分子形成多种氢键,如R12(7),R22(9)和R12(4)等,以及H2biim配体之间的π-π堆积,阳离子不对称单元构筑了多维结构的超分子配合物.  相似文献   

9.
丙酰皮考林酰肼(C_9H_(11)N_3O_2 )的合成和晶体结构   总被引:1,自引:0,他引:1  
吴文士  刘世雄 《结构化学》2001,20(3):226-228
合成了标题化合物(C9H11N3O2,Mr=193.21),晶体属于单斜晶系,空间群为C2/c, a=13.703(1),b = 9.142(1), c = 16.437(2)?, ( = 105.547(3)(,V = 1983.8(4)?,Z = 8, Dc=1.294g/cm3, F(000)= 816,(??o?α)=0.094 mm-1,R=0.0527, wR=0.1517,I(2((I)的可观察衍射点1596个。有机分子间以氢键相联并形成网状结构,N(2)-H...N(1a)(a: -x+1, y, -z+1/2)和N(3)-H…O(2b)(b: -x+1/2, y-1/2, -z+1/2)键键长分别为3.007(2)和2.786(2)?。  相似文献   

10.
用室温固相合成法研究了酯基锡EtO2CCH2CH2SnCl3 1 与Schiff碱2-HOC6H4- CH=NC6H4Br-3 2 合成标题化合物(3-EtO2CCH2CH2SnCl3)?2-HOC6H4CH= N-C6H4Br-3) 3的配位反应。利用元素分析, UV-VIS, IR, 1H NMR等方法对配合物的结构进行了表征, 采用单晶X-射线衍射方法测定了3的晶体结构。3的分子式为C18H19BrCl3NO3Sn, Mr = 602.29。晶体属三斜晶系, P空间群, a = 7.75(2), b = 10.578(2), c = 13.936(3) , = 83.663(3), = 75.909(3), = 76.691(3), V = 1077(4) 3, Z=2, Dc = 1.858 g/cm3, F(000) = 588, = 3.433 mm-1, R = 0.0547, wR = 0.1341。Schiff碱是以酚羟基上的O原子与中心Sn原子配位, Schiff碱分子中的分子内氢键, 形成配合物后得到加强, 提出了3的2种共振式。与中心Sn原子配位的3个Cl原子、2个O原子和1个C原子形成畸变的八面体结构。  相似文献   

11.
膜荚黄芪苷元的结构   总被引:5,自引:0,他引:5  
曹正中  俞家华  甘立宪  周维善 《化学学报》1983,41(12):1137-1145
从膜荚黄芪的根中分得膜荚黄芪皂苷甲,皂苷乙和皂苷丙.膜荚黄芪皂苷甲是主要成分.药理试验有降压和抗炎作用、皂苷甲经Smith氧化降解得到膜荚黄芪苷元1.用IR,~1HNMR,~(13)C NMR,MS和化学降解证明其结构为1.根据镧系位移试剂的~1H NMR,1的C_(20)和C_(24)的构型分别确定为S和R.  相似文献   

12.
膜荚黄芪苷的结构   总被引:6,自引:0,他引:6  
前文报道从中药膜荚黄芪(Astragalus membranaceus Bunge)根部分离得到三个皂苷ASI、AS Ⅱ和 AS Ⅲ.AS Ⅰ和 AS Ⅱ分别称为膜荚黄芪苷(astramembrannin)Ⅰ(1)和Ⅱ(2),AS Ⅲ经鉴定为胡罗卜苷(dancosterin)(3).本文报道1和2的结构测定.1为主要成份,具有降压、抗炎、镇静、镇痛和调节代谢的作用.1和2经 Smith 降解均得苷元4~(**),用酸水解经鉴定1含有木糖和葡萄糖,2仅含木糖.  相似文献   

13.
黄芪葡聚多糖的化学结构   总被引:19,自引:0,他引:19  
方积年  WAGNER  H 《化学学报》1988,46(11):1101-1104
从植物黄芪(Astragalus mongholicus Bunges)根的碱性水提取液中得到一水溶性多糖黄芪葡聚糖. 它由单一葡萄糖残基构成, 分子量为5x10^4. 甲基化、过碘酸盐氧化、Smith降解和部分水解后, 揭示了它是以1,4-葡萄糖残基为主链, 并在6-O有分枝、重复单元为10个葡萄糖残基的葡聚糖(结构如3所示).  相似文献   

14.
黄芪属植物化学研究 II: 梭果萤芪花A和B的结构鉴定   总被引:1,自引:0,他引:1  
本文从梭黄芪的干燥根中分得胡罗卜芪, β-谷甾醇和两个新黄芪皂芪A和B, 经光谱和化学方法确证, 芪A为3-O-[α-L-鼠李吡喃糖基(1→2)-β-D-木吡喃糖基]-25-O-β-D-葡萄吡喃糖基环黄芪醇花B为3-O-[α-L-鼠李吡喃糖基(1→2)-(3'-O-乙酰基)-β-D-木吡喃糖基]-25-O-β-D-葡萄吡喃糖基环黄芪醇。  相似文献   

15.
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   

16.
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   

17.
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   

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.
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   

20.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号