冬凌草甲素的晶体结构

冬凌草甲素,C_(20)H_(28)O_6,Mr=364.44,是一种从中药中提取的抗癌药,它的晶体结构分析表明晶体属正交晶系的空间群P2_12_12_1,晶胞参数为α=13.316(9),b=21.302(2),c=13.015(1),V=3697(9)~3。Z=8,D_c=1.31g/cm~3,D_o=1.30g/cm~3,F(000)=1568。该分子是四环二萜类化合物,A环和C环是椅型结构,B环是船型结构;D环是部分共轭五员环,为半椅型结构,环上相邻的两个双重键侧基组成一个六原子的共轭平面。     

鹤草酚的晶体结构和分子结构

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.     

5-苯基-3,5-二乙氧基-2(5H)-呋喃酮的晶体结构

标题化合物C14H16O4的晶体结构用X-射线单晶衍射法测定。晶体属三斜晶系,P空间群,晶胞参数a =8.696(2), b=8.943(2) , c=9.379(2) ?, ( = 69.28(3), ( =76.67(3), ( =80.28(3)o, V=660.8(3) ? 3, Z=2, Mr=248.28, Dx=1.248 g/cm3, F(000)=264, μ(MoK()=0.0851 mm—1。晶体结构用直接法解出,经全矩阵最小二乘法对原子参数进行修正,最终的偏离因子为R=0.061, wR=0.089。标题化合物有2个环：呋喃酮环和苯环。由C(1),C(2),C(3),C(4),O(4)构成的五元呋喃酮环的5个原子较好地处于1个平面上,平均偏差为0.0078?。O(2),O(3) 两个原子与呋喃酮环共平面。呋喃酮环和苯环之间的两面角为79.39o。     

反-1,2-双[2'-(5'-苯基恶唑基)]乙烯的晶体结构

用X射线单晶衍射法测定了反-1,2-双[2'-(5'-苯基恶唑基)]乙烯(POEOP)的晶体结构,POEOP晶体属单斜晶系, 空间群为P2~1/C, a=0.8268(2), b=0.5977(2), c=1.6292(3)nm;β=100.55(2)°; v=0.7915nm~3; Z=2; d~x=1.319g/cm~3。POEOP分子具有中心对称性,它的两个苯环和两个恶唑环是彼此平行的, 但整个分子却稍有些扭曲成螺旋浆式构型。键长数据表明POEOP分子中苯环与恶唑环以及恶唑环与C'=C双键间均有很大程度共轭。     

软珊瑚群柱虫中Clavutriolin衍生物的晶体结构和绝对构型的测定

软珊瑚群柱虫中的一个化学组分Ia,经乙酰化分离得到其衍生物Ib,用x射线晶体结构分析法测定Ib的晶体结构。Ib属正交晶系,空间群P2_12_12_1,a=12.722(2),b=14.726(4),c=12.255(3),z=4。由Ib的晶体结构分析结果推断Ia的分子式为C_(20)H-(33)O_4Cl。它是一个具有五、十一员双环碳骨架的新型含氯二萜。十一员环上带有一个环氧基和一个环外双键,分子中含有两个叔羟基和一个伯羟基。利用C1、O和C对Cukα辐射的反常散射,测定对于对映体敏感的Friedel反射对的Bijvoet差,确定了Ib的绝对构型,进而确定Ia的绝对构型。     

豆荚内酯A的晶体结构和分子结构

本文报道软珊瑚提取物豆荚内酯 A 的晶体结构和分子结构.分子式为 C_(22)H_(30)O_5,M_r=374.5,晶体属正交晶系,空间群为,P2_12_12_1,a=8.753(2),b=8.887(3),c=54.247(14)(?),V=4220(2)(?)~3,Z=8,D_x=1.17Mg·m~(-3),F(000)=1616e.强度数据用 Cu Kα辐射、四圆衍射仪收集,结构用直接法解出.经最小二乘法修正,其偏离因子 R=0.064.分子骨架由无规则的[-+-+-++++-+--]型十三环二烯和“信封式”γ-内酯环组成,两者以顺式稠合.不对称单位两个分子构型基本相同.晶胞中分子堆积较疏松.     

呋喃氟脲嘧啶的晶体结构

呋喃氟脲嘧啶C_8H_9FN_2O_3晶体属三斜晶系,a=6.0044(23),b=9.0221(80),c=16.7021(109),α=99.779(59),β=93.426(43),γ=94.178(55)°。空间群P_1~-,Z=4。用Nicolet R3四圆衍射仪收集强度数据,结构由SHELXTL系统的直接法解出。经最小二乘修正,R=0.078,R_w=0.069。结构测定结果表明,四氢呋喃环具有假旋转角P=218.6°(分子1)和P=177.9°(分子2),两个分子均为S型构造[C(6)endo—C(7)exo]。脲嘧啶基相对于五元环具有正的取向,x=—53.1(分子1)和x=—18.4(分子2)     

钛、锆、铪有机化合物的研究——四(环戊二烯基)二(邻甲苯基)和四(甲基环戊二烯基)二(对甲苯基)-μ-氧合二锆的晶体结构和分子结构

本文报道了四(环戊二烯基)二(邻甲苯基)-μ-氧合二锆[二聚物(Ⅰ)]和四(甲基环戊二烯基)二(对甲苯基)-μ-氧合二锆[二聚物(Ⅱ)]的晶体结构和分子结构。二者均属单斜晶系,具有相同的空间群C_(2h)~5-P (21)/a。二聚物(Ⅰ)晶胞中含有四个分子,晶胞参数为a=19.122,b=16.319,c=9.296,β=92°1′。二聚物(Ⅱ)晶胞中含有两个分子,晶胞参数为a=20.076,b=8.205,c=10.016,β=104°41。两种二聚物分子构型的主要差别在于:二聚物(Ⅰ)不具有对称中心,Zr—O—Zr氧桥稍呈弯曲;二聚物(Ⅱ)以氧原子为对称中心,Zr—O—Zr氧桥呈直线型,据此讨论了空间效应和分子的电子结构。     

混配配合物中配体间芳环堆砌作用研究(Ⅰ)——[Cu(C10H8O4)(C10H8N2)(H2O)]·2H2O配合物合成、晶体结构和红外光谱

合成了Cu(bipy)[BMA]·3H2O混配配合物单晶(BMAH2为苄基丙二酸),测定了其晶体结构.该晶体属于正交晶系,空间群为Pbca,晶胞参数:a=1.659 3(3)nm,b=1.467 3 nm,c=1.674 7(3)nm,Z=8.R和Rw分别为0.037和0.038.晶体结构表明分子间芳环堆砌作用和分子间氢键作用是此晶体形成的主要作用力.晶胞中的分子间芳环堆砌作用不同于已往的文献报道,具有分子识别的特点.     

C_(60)加合物的X-射线晶体结构已确定

美国加州大学伯克利分校的化学家新近测定了C_(60)O_sO_4·(4-Me_3C—C_5H_4N_2),加合物的x-射线晶体结构。这是第一个有关C_(60)化合物的晶体结构,从而首次直接证实了C_(60)(buckminsterfullerence)分子形似足球。晶体结构的测定表明O_sO_4中的两个氧原子加成到了C_(60)分子中两个毗邻碳原子上,碳-碳键没有断裂,这两个碳原子的位置类似于萘环骨架中的     

X-RAY CRYSTALLOGRAPHIC STRUCTURE OF Meta-AND Para-DIMETHYL ESTER OF PYROMELLITIC ACID

The polycrystalline powder of para- and meta-dimethyl ester of pyromellitic acid (PMDE)have been prepared by fractional crystallization, and their crystal structures have been de-termined by Wide-Angle X-ray Diffraction (WAXD). Both p-PMDE and m-PMDE wasfound to be orthorhombic crystal system, and their unit cell parameters a = 0.840nm,b = 0.707 nm, c = 1.136 nm and a = 1.032 nm, b = 0.835 nm, c = 0.714 nm, respectively.Space group all belongs to P_(mmm). p-PMDE has two molecules per unit cell with crystaldensity 1.388g.cm~(-3), while m-PMDE has two molecules per unit cell with crystal density1.522 g.cm~(-3). Indices of crystal diffraction peaks are also detailed in the present work.The difference in crystal structures between p-PMDE and m-PMDE has thus been usedto explain the curing behavior of isomerically pyromellitic dianhydride-based poly(amicester)s.     

基于对羟基苯乙酸及邻菲啰啉的锰配合物的合成、晶体结构、荧光性质及与DNA作用

合成了配合物[Mn(C8H7O3)2(phen)2].H2O(C8H8O3=对羟基苯乙酸,phen=1,10-邻菲啰啉),并通过元素分析、红外光谱和热重分析对产物进行了表征,用单晶X-射线衍射方法测定了配合物的晶体结构。配合物属于单斜晶系,空间群C2/c,晶胞参数:a=2.485 1(3)nm,b=0.920 85(3)nm,c=1.718 3(3)nm,β=117.363(10)°,晶胞体积:V=3.492 2(9)nm3,晶胞内结构基元数Z=4,式量Mr=735.64。晶体结构分析表明,Mn(Ⅱ)离子分别与2个对羟基苯乙酸根的2个氧原子和2个1,10-邻菲啰啉中的4个氮原子配位,构成1个畸变的八面体结构。连续的八面体结构基元组成了一维链状聚合结构。另外,用荧光光谱研究了配合物与DNA之间的相互作用。     

苯四甲酸桥连的镍配合物[Ni(btec)(H2O)4][Ni(imi)2(H2O)4]·2H2O的合成及结构

At room temperature, a coordination polymer [Ni(btec)(H2O)4][Ni(imi)2(H2O)4]·2H2O was synthesized by reaction of NiCl2·6H2O, 1,2,4,5-benzenetetracarboxylic dianhydridc and imidazole in a water/THF solution. The structure was determined by X-ray diffraction crystal structure analysis. It crystallizes in triclinic P1 space group with the crystal cell parameters of a=0.67542 (2) nm, b=1.000 14 (1) nm, c=1.09088 (3) nm, α=74.140(2)°, β= 74.388(1)°, y=73.239(2)°, and V=0.664 09(3) nm3, Z=1. The crystal structure shows that Ni1 atom is coordinated by four water and two imidazole molecules, while Ni2 is coordinated by four water molecules and two carboxyl oxygen atoms. The 1,2,4,5-benzenetetracarboxylate ions bridge Ni2 coordination centers to form one-dimensional chain structure. Moreover, the chains are further linked together by hydrogen bonds to form a two-dimensional network. CCDC: 295873.     

主体分子2,2′-二羟基-1,1′-二萘与客体分子乙酸乙酯晶态包结物的研究

用X射线单晶衍射分析法研究主体分子2，2’-二羟基-1，l’-二萘与客体分子乙酸乙酯（3：1）晶态包结物的晶体结构。其化学式为C64H50O8，Mr=947．08。晶体属三斜晶系，空间群为P1。晶胞参数：个独立衍射点，5823个可观察点（F≥3σF）。2，2’-二羟基-1，1’-二萘与乙酸乙酯形成以氢键联系的包结物3个主体分子中的6个羟基形成21环的氢键体系。     

β-氰乙基-α-二茂铁邻氟代苄基醚的晶体和分子结构

This paper reports the crystal and molecular structure of β-cyanoethyl-α-ferro cenylfluorobenzyl ether (C_5H_5FeC_5H_4CH(OCH_2CH_2CN)C_6H_4F). The title crystal belongs to the triclinic system and the space group is P1 with crystal parameters: a=0.7849(8) nm, b=1.1744(3) nm, c=1.9337(4) nm, α=74.99(1)°, β=87.28(5)°, γ=86.61(5)°, V=1.7176(2) nm, Z=4, D_c=1.405 g cm~(-3). The crystal was solved with direct method and fourier synthesis, refined with full matrix least-squares. The refinement eonveraged to R=0.043.There are two molecules in an asymmetry unit. The geometrical features of the molecules and the characteristics of the molecular packing are discussed.     

Synthesis and Crystal Structure of Cobalt(II) Complex [Co(H2O)2(bpe)(OAc)2](4,4''-dpdo

The reaction of Co(OAc)2 with bpe and 4,4'-dpdo in an aqueous-alcohol solution affords the formation of red crystals of [Co(H2O)2(bpe)(OAc)2](4,4'-dpdo (bpe = trans-1,2-bis(4- pyridyl)ethylene, 4,4'-dpdo = 4,4'-dipyridyl N,N'-oxide). The molecular and crystal structures were determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group P with a = 7.6146(9), b = 8.6691(11), c = 10.344011 A, α = 88.311(3), β = 76.992(3), γ = 75.809(3)°, V = 644.7613 A3, Z = 1, C26H28CoN4O8, Mr = 583.45, Dc = 1.503 g/cm3, μ = 0.724 mm-1, F(000) = 303, T = 223(2) K, the final R = 0.0477 and wR = 0.1177 for 3199 observed reflections with I > 2σ(I). In the crystal the cobalt atom is six-coordinated by oxygen atoms from two carboxylic molecules, two nitrogen atoms from the bpe ligands and two water molecules, completing an octahedral geometry. The structure of the title complex consists of neutral chains containing cobalt(II) ions bridged by mutually trans bpe molecules. The adjacent chains are connected through weak hydrogen bonds to form a two-dimensional structure.     

Über Chalkogenolate. 117 [1]. Untersuchungen über Guanidinodithioformiate 4. Kristall- und Molekülstruktur der Guanidinodithioameisensäure

On Chalcogenolates. 117. Studies on Guanidinodithioformates. 4. Crystal and Molecular Structure of Guanidinodithioformic Acid Guanidinodithioformic acid crystallizes with Z = 4 in the monoclinic space group P2₁ with cell dimensions a = 4.204(3) Å, b = 10.422(5) Å, c = 12.491(5) Å, β = 93.9(3)°. The crystal and molecular structure has been determined from single crystal X-ray data at 20°C and refined to a conventional R of 0.0242. The asymmetric part of the unit cell contains two molecules in the dipolar form with different conformation. The molecules have delocated double-bonds and are linked together by N? H···S hydrogen bridges.     

对位取代苯甲酸酯的晶体结构研究Ⅲ对羟基苯甲酸乙酯p—HOC_6H_4CO_2C_2H_5的晶体结构

对羟基苯甲酸乙酯(p-EHB)晶体属单斜晶系,空间群C_(2h)~/a,晶胞参数a=11.579(4),b=13.182(1),c=11.765(4),β=107.76(3)~0,V=1710.2,Z=8,D_c=1.291g/cm~3。R=0.056,R_w=0.053。结构测定结果表明,晶胞中8个分子分成两组按两套不同坐标排布,其分子构型极相似。分子间H键数目较少,但键的作用较强。文中还谈到分子空间排布问题。     

Synthesis and Crystal Structure of Complex [Cdq3] [Cd（qH）3]（ClO4）CH3OH（q = 8-Quinolinolate, qH = 8-Quilinolinol）

1 INTRODUCTION 8-Quinolinolate is a very useful ligand and used to synthesize many complexes with special physical properties. For example, the complex tris(8-quinoli- nolate)aluminum(III) displays distinguished physical property in the area of electroluminescence ma- terials[1]. Based on tris(8-quinolinolate)aluminum(III), high-luminance low-voltage driven devices have been made, which opens the route to design low-cost large area displays and illuminators. The crystals thatcontain com…     

Structural and conformational properties of fluoroformic acid anhydride, FC(O)OC(O)F

The conformational properties and geometric structures of fluoroformic acid anhydride, FC(O)OC(O)F, have been studied by vibrational spectroscopy, gas electron diffraction (GED), single-crystal X-ray diffraction, and quantum chemical calculations (HF, MP2, and B3LYP methods with 6-31G* and B3LYP/6-311+G* basis sets). Satellite bands in the IR matrix spectra, which increase in intensity when the matrix gas mixture is heated prior to deposition as a matrix, indicate the presence of two conformers at room temperature. According to the electron diffraction analysis, the prevailing conformer is of C(2) symmetry with both C=O bonds synperiplanar with respect to the opposite C-O bond ([sp, sp] conformer). The minor conformer [15(5)% from IR matrix and 6(11)% from GED] is predicted by quantum chemical calculations to possess an [sp, ac] structure. FC(O)OC(O)F crystallizes in the orthorhombic system in the space group P2(1)2(1)2(1) with a = 6.527(1) angstroms, b = 7.027(1) angstroms, and c = 16.191(1) angstroms and four formula units per unit cell. In the crystal, only the [sp, sp] conformer is present, and the structural parameters are very similar to those determined by GED.