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 15 毫秒
1.
<正> The title compound, C24H20As2(Mr=458.24), crystallizes in mono-clinic with space group P21/n and a=6.268(2), b=7.494(2), c=21.340(7)A, β= 91.027(3)°, V=1002.6 A3, Z=2, D.x=1.518gcm-3. The final value of R is 0.059 for 1619 observed reflections. The four phenyls arrange in a staggered trans-conformation around the As-As' bond.  相似文献   

2.
<正> INTRODUCTION. Four compounds of diterpenoids that have in vitro cytotoxity against cultured Hala cells have been obtained by means of extraction from Rabdosia serra(Maxim) Hara, a chinese medical herb. They are Rabdoserrin A (Rab A), Rabdoserrin B (Rab B), Excisanin A and Kamebakaurin (Kam). Among them, Rab A and Rab B are new compounds. Crystal structures of Rab A and Kam have been solved. The chemical structure of Rab B has been  相似文献   

3.
钩吻素子(Koumine)是钧吻生物碱(Kou-Wen Alkaloids)中的单体之一,其分子式为C_(20)H_(22)N_2O。它的晶体属单斜晶系,空间群为P2_1,晶胞参数为:α=8.422(0),b=13.209(1),c=7.881(1)A,β=108.201(9)°,V=834.995A~3;Z=2;D_c=1.29g/cm~3。 本文报道的钩吻素子是1981年Khuong-Huu F等人报导的钩吻素子的一个立体异构体,它们是钩吻素子的两个非对映体旋光异构体。  相似文献   

4.
<正> Introduction. Rabdoserrin-D C_(20)H_(30)O_5 is extracted from Rabdosia serra (Maxim) Hara, a Chinese medical herb with antitumourous activities. Tests show that this compound has a high inhibitory effect on the Hela cell cultured outside the body and thus it is worth further studying, The investigation on the  相似文献   

5.
<正> The structure of humosine A, C20H19NO5, which represents a new kind of phthalide isoquinoline alkaloid,has been determined by X-ray diffraction analysis. The compound crystallized in the space group P212121 with a=7.654(2), b=12.926(2), c= 17.018(8) A, Z=4, V=1681.7A3, Dx=1.459g.cm-3, μ(Moke(?))=1.014 cm-1, F(000)=776. The structure was solved by direct methods, and refined by full-matrix least-squares with final R = 0.032 for 1517 observed reflections (I≥3σ).  相似文献   

6.
7.
8.
鹤草酚晶体属三斜晶系,空间群为PI,晶胞参数为a=9.901(3),b=11.195(4),c=11.752(4)Å,α=80.74(3),α=75.66(3),γ=76.46(3)°,晶胞内分子数Z=2.用SyntexP3/R3型四圆衍射仪收集到2891个独立衍射强度.以直接法SHELXTL解出晶体结构.结构参数的修正采用了块对角矩阵最小二乘法,最后得偏离因子R=5.7%.晶胞中含有d-,l-两种对映体分子,它们彼此以I连系组成外消旋体.每分子中的两个六环分别同相邻的氧共面,其双面角为14.2°.两个六环通过碳(sp3)桥相连,并由于形成分子内氢键O-H…O(分别为2.705Å和2.745Å)而限制了自由转动.  相似文献   

9.
<正> C14H10N2,Mr =206.24, space group P21/n, a =5.861(3), b =10.230 (5), c =17.440(11) A,β=92.07(5)°,V= 1045(1) A3,Z=4, Dx=1.31 g.cm-3, MoKa radiation,u=0.73 cm-1,F(000)=432,R=0.063 for 1054 observed reflections. 2-Phenylquinoxaline molecule is approximately planar. The dihedral angle between the quinoxaline ring and the substituted phenyl ring is 7.0°. The C-C bond distance connecting these two rings is 1.495(4) A. The whole molecule is a conjugation system.  相似文献   

10.
<正> Triptonide, C20H22O6, was extracted from tripterygium wilfordii Hook F. of Fujian province and its structure was determined by X-ray crystallo-graphic analysis, Mr = 358. 39, monoclinic, P21,a = 11. 144(5), 6 = 6. 467(2), c= 12. 681(6)(?), β=103.54(4)°, V= 888. 4(?)3. Z = 2, F(000) = 380, Dc= 1. 34g/ cm3. The structure was solved by direct methods and refined by full matrix least-squares method to a final R value of 0. 042 for 1934 reflections with I> 3σ(I). Crystals of triptonide are isostructural with those of triptolide.  相似文献   

11.
继苯甲酰羟胺—钨酰螯合物WO_2(C_7H_6O_2N)_2的晶体结构测定后,本文报导了整合物MoO_2(C_7H_6O_2N)_2·C_6H_(13)OH的结构和特性,并初步提出了酰羟胺类试剂用于钨钼分离的可能性。苯甲酰羟胺—钼酰螯合物的分子及晶体结构已由四园衍射仪测定,晶体属空间群C_(2h)~5—P2_1/c,晶胞参数a=9.142(1),b=21.591(3),c=11.662(3)A,β=90.31(1)°,Z=4,最终吻合因子R=0.079.虽然结构中结合的已醇分子无法定位,但它与螯合物分子间强烈的氢键键合作用,则是十分明显的,这很可能是影响苯甲酰羟胺对钨钼分离效果的重要因素之一。  相似文献   

12.
Abstract

The crystal and molecular structure of p-NO2C6H5CH2CONHCH2COOH or C10 H11 N2O5 has been determined by single crystal x-ray diffraction techniques. The compound crystallizes in the space-group P21. /c with four molecules in a unit cell of dimensions: a = 11.8748(5)Å, b = 11.2732(4)Å, c = 8.8073(5)Å and β = 112.966(4)°. The structure was solved by direct methods and refined to a final value of R = 0.042. The molecule assumes a conformation similar to that found for the analogous side-chain in the penicillin G molecule and hence should be a convenient model system in studying copper catalyzed degradations of penicillin. The hydrogen bonding between the amide oxygen of one molecule to the carboxylic acid proton, 2.67(1)Å, and the amide nitrogen, 2.91(1)A, of another molecule creates a three-dimensional network identical to that found for hippuric acid.  相似文献   

13.
<正> Toxocarol C6H12O4 is a separated product from the plant of Toxocarpus (himalensis Falc. ex Hook. f.). It crystallizes in orthorhombic, the space group D2h-Pnca with a= 10.129(2), b= 11.297(3), c= 11.814(3)A, V=1351.9 A3, Z=8, Dc= 1.46 g.cm-3; m.p= 150.5°-151.5℃,μ(Mo)=1.3 cm-1. The result of structure analysis shows that the compound is a chair cyclohexan-tetrol .There is a complex net of hydrogen bonds in the crystal.  相似文献   

14.
秃毛冬青甲素为一种新木脂类化合物,在氯仿中重结晶得无色透明的六边形晶体,它的分子式为C14H16O6,分子量280.09,计算密度1.443g/cm3,m.p.195~197℃.  相似文献   

15.
16.
<正> Crystal and molecujar structure of the title compound, C29H19NO3, was determined by single crystal X-ray diffraction analysis. .Mt=429. 48, monoclin-ic, space group P21/n, a = 10. 365 (3), b= 14. 614(4), c= 14. 857 (4) A ,β= 103.55(2)°,V=2186. 1(10) A3, Z=4, Dc= 1. 30g/cm3,μ(MoKa) = 0. 81cm-1, F (000) = 919. 87. Final residual R value was 0. 0704 and Rw = 0. 0704. The indo-hzine ring is conjugated only with the 1-benzonyl group.  相似文献   

17.
<正> To elucidate structural relations between benzo-13-crown-4 and its similar crown compound. We determined the crystal structure of the title compound, which is a pure crown. The results of our investigation show that the dihedral angle between the planes of benzo-ring and of the O-atoms in the crown ring is 43.5°. The related distances between O atoms in benzo-13-crown-4 are 2.651 to 4.906, respectively.  相似文献   

18.
<正> 3-Benzoylcoumarine C16H10O3, Mr = 250. 26, monpclinic, space group P21/n, a =11. 744(1), 6 = 16.837(2), c=12. 525(2)A , β= 100. 00(1)°, Z = 8, Dc =1. 363g/cm3, Do = 1. 382g/cm3, F( 000) = 1040, μ(MoKa) = 0. 880cm-1. R and Rw were 0. 048 and 0. 049, respectively, for 2490 observed reflections. X-ray structural analysis reveals that the title compound contains 3 planes intersecting each other with different dihedral angles and thus the whole molecule displays non-planar configuration. This result is consistant with the previous conclusion from photochemical study.  相似文献   

19.
<正> Diethylaminoacetonitrile (1) reacts with phthalimide (2) or succirnide (3) to produce N-cyanomethyl phthalimide (4) C10H6O2N2 (Mr = 186. 168) or N-cyanomethyl succirnide (5) C6H6O2N2(Mr= 138. 128),respectively. Their molecular and crystal structures were determined by IR, 1H NMR, MS and X-ray diffraction analysis, compound (4) crystallizes in monoclinic space group P21/a(P21/c) ,with cell dimensions 0=8. 225(4) ,6= 10. 956(4),c= 10. 041(5) A .β=102. 43(4)°,V=883. 1A3, μ= 0. 90cm-1, F (000) = 384, Z = 4; compound (5) crystallizes in monoclinic space group P1,with a=8. 404(2),b = 9. 710(2),c= 10. 093(2) A ,α= 104. 73(2)°,β = 108. 55(2)°, γ= 112. 03(2)°,V= 655. 2 A3,μ= 1.0cm-1 ,F(000) = 288,Z= 4. The average inner angles of the five-membered ring of (4) and (5) are about 108°. The imide and the carbon atom of the methylene radical of N-cyanomethyl and phenyl ring are all in one plane . so the bonds are delocalized and the α-hydrogen atoms of N-cyanomethyl are activated. The syntheses and crysta  相似文献   

20.
<正> C9HsN2O3S, Mr=222.218,monoclinic space group P21/n,B=12,584 (4).b =10.788(3), c= 15.124(4)A,β=106.83(2)°,V=1965.3A3,Dc= 0,75 g/cm3,Z=8,μ(MoKα)=1.5cm-1, F(OOO)=456(e),λ=0.7107A,R=0.067, Rw=0.059. Two Bolecules are in an asymmetric unit in the crystal. Structural analysis showed that all atoms of the two rings of benzoic sulfinide are in the sane plane which is normal to plane S(1)O(1)O(2). The C=N group is above the plane of the two rings.  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