Preparation and crystal structure ofexo-2,exo-6-dihydroxy-2,6-dimethyl-9-oxabicyclo[3.3.1]nonane

In a further exploration of the structural factors causing alicyclic diols such asexo-2,exo-6-dihydroxy-2,6-dimethylbicyclo[3.3.1]nonane (1) to adopt the helical tubuland inclusion host structure, the title compound (8) has been synthesized and its crystal structure determined. This 9-oxa analogue of (1) has a totally different structure [C₁₀H₁₈O₃; orthorhombic;P2₁2₁2;a 18.989(4),b 19.064(3),c 14.256(3) Å;Z 20; with finalR 0.065] due to involvement of the ether oxygen atom in the hydrogen bonding network. The structure of the diol (8) approximatesP¯42₁ c symmetry, and 16 of the 20 molecules per cell create a hostlike structure of this symmetry, which consists of tightly bound hydrogen bonded pillars parallel toc. The remaining guestlike molecules occupy inequivalent pseudo ¯4 sites separated byc/2 to form weakly bound columns parallel toc. Hydrogen bonds also occur between the pillars and columns. An ordered structure with sensible intermolecular contacts can be formed inP2₁2₁2₁ with thec axis doubled. A difference betweena andb axial lengths correlates with a difference in occupancies of pseudo-¯4-related sites for the guest-like component of the structure.     

Formation of Supramolecular Polymers Constructed by Cyclodextrins with Cinnamamide

-Cyclodextrin having cinnamamide at 6- or 3-positions (6-CiNH--CD, 3-CiNH--CD) and -cyclodextrin with cinnamamide on 6-position (6-CiNH--CD) have been prepared. Supramolecular structures were formed in the solid state or aqueous solutions and characterized by measurements of NMR and vapor pressure osmometry (VPO). The results indicate that 6-CiNH--CD formed insoluble supramolecular polymers in the solid state, while 6-CiNH--CD and 3-CiNH--CD formed supramolecular complexes in aqueous solutions. 6-CiNH--CD was found to form a dimer in an aqueous solution. 3-CiNH--CD formed intermolecular complexes to give supramolecular polymers. The differences of the position of guest part on cyclodextrins caused to give a variety of supramolecular structures in aqueous solutions.     

Studies on novel cyclodextrans: Inclusion of C60 and C70

Cycloisomalto-heptaose (CI-7) and cycloisomalto-octaose (CI-8) are two novel cyclodextrans. Treatment with C₆₀ or C₇₀ by kneading leads to the formation of four distinct water-soluble inclusion complexes: CI-7/C₆₀ (2: 1), CI-8/C₆₀ (2: 1), CI-7/C₇₀ (2: 1) and CI-8/C₇₀ (2: 1). Their formation and structures have been examined by UV vis spectroscopy, X-ray powder diffraction and fluorescence spectral studies. The reaction is a reversible process.     

内含式化合物X@Al12P12的结构与稳定性研究

采用B3LYP/6-31G*方法, 对内含式化合物X@Al₁₂P₁₂ (X＝Li^0/＋, Na^0/＋, K^0/＋, Be^0/2＋, Mg^0/2＋, Ca^0/2＋, H和He)的不同对称性构型进行计算, 讨论其最稳定构型的几何参数、布居分析、偶极矩、电离势、包含能、频率、HOMO-LUMO能隙和自旋密度．发现X@Al₁₂P₁₂化合物中, 客体X＝Na^0/＋, K^0/＋, Mg和He几乎处在笼的中心, Be和Ca^0/2＋处在中心附近0.033 nm的半径内, Li^0/＋, Be^2＋, Mg^2＋和H很大程度上偏离笼的中心位置. 大部分金属内含式化合物的C₃对称性构型稳定．Li^0/＋, Be^0/2＋, Mg^2＋, Ca^2＋和H与其它离子相比更易嵌入笼内形成稳定的内含式化合物.     

环糊精-苯丙氨酸超分子体系的包合现象与分子识别

通过紫外-可见光谱探讨了水溶液中α-环糊精(CD 1),β-CD 2,七(2, 6-二-o-甲基)-β-CD 3和γ-CD 4与D-、L-、D,L-苯丙氨酸(Phe)形成超分子包合物的稳定常数(K)。手性或外消旋苯丙氨酸与同一主体结合能力的强弱顺序为:L- >D,L- >D-Phe,各体系的K_L/K_D值在1.65～3.01之间,给出了较好的异构体分离。但三种形式的苯丙氨酸与这些主体的缔合常数均较小(K< 3×10²mol·L^-1)。就不同主体而言,K值的次序为:3 >1 >4 >2,并不完全等同于K_L/K_D的顺序:2 >1 >3 >4。     

Separation of closely related structural isomers by inclusion complexation with tailor-made host compounds. Crystal structures of 2,2-di (p-hydroxyphenyl) propane and Its 1:1 complex withp-cresol

The crystal structures of the 2,2-di(p-hydroxyphenyl)propane host and its 1:1 adducts withm-andp-cresol guests have been studied. The preferential complexation of this host withp-cresol overm-cresol is related to the opposite trend exhibited by 1,1-di(p-hydroxyphenyl)cyclohexane; both hosts can separate effectively the two cresols from their liquid mixture by crystalline inclusion. A plausible explanation of the different inclusion features is provided by examining the intermolecular association in the corresponding solids. The analysed structures are stabilized by strong and continuous H-bonding between the constituent entities along two dimensions, and by weak van der Waals forces along the third axis. The p-cresol complex of the title host reveals a unique arrangement within and a more efficient packing of the layered structure, and thus represents a more stable and less soluble crystal lattice than itsm-cresol analog. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82099 (8 pages).     

邻-甲氧基苯酚和α-,β-环糊精包合现象的理论与实验研究

通过紫外可见光谱法考察了水溶液中邻-甲氧基苯酚(o-Mop)和α-与β-环糊精(CD)的分子间相互作用, 利用Hildebrand-Benesi方程给出了两个包合物的稳定常数(K_s). 采用半经验PM3方法研究了α-,β-CD和o-Mop及其类似物苯酚(Phe)、丁香酚(Eug)之间的包络作用, 阐述了这些主客体包合作用过程中体系能量随主客体相对位置改变而变化的细节, 据此推断出主-客体包合物可能的分子结构, 计算了包合物的稳定化能(ΔE_s). 研究结果表明, 本文所选主客体体系而言, 当客体和同一种主体分子作用时, 超分子包合物的ΔE_s随着客体分子苯环上取代基团数目的增多而增加. 基于PM3方法优化得到的主-客体包合物在真空中的分子结构和通过实验方法在水溶液中测定的结构一致.     

Inclusion complexes of the natural product gossypol. Crystal structure of the 2:1 complex of gossypol with amyl acrylate

The crystal structure of the 2: 1 inclusion complex of gossypol with amyl acrylate has been determined by X-ray structure analysis. The crystals of (C₃₀H₃₀O₈)₂C₈H₁₄O₂ are triclinic, space group P ,a = 14.425(2),b = 15.519(1),c = 16.409(2) Å, =97.89(1), = 117.80(1), =67.01(1)° (reduced cell:a = 14.425(2),b = 15.519(2),c = 16.017(2)Å, = 92.19(1), = 115.01(l), =67.01(1)°],V = 2986.7(5) ų,Z = 2,D _x = 1.31 g cm^–3, (CuK ) = 7.40 cm^–1,T = 292 K. The structure has been solved by direct methods and refined to the final R value of 0.059 for 5155 observed reflections. The gossypol molecules bonded via several hydrogen bonds form centrosymmetric tetramers. The two independent gossypol molecules, A and B, are related within the tetramer by a local noncrystallographic 2-fold axis. The host molecules in the crystal form cavities in which two guest molecules are placed. The ester molecule interacts via a pair of C-...H-O hydrogen bonds with two gossypol molecules of the same chirality and belonging to the same tetramer unit. The amyloxy group of the ester molecule shows a very large thermal motion. It adopts a non-extended conformation in which it can be fitted into the cavity formed by the host molecules.     

β—环糊精对D／L—酪氨酸对映体的手性识别及超分子包合物的合成

利用圆二色谱研究了β－环糊精（β－ＣＤ）对Ｄ／Ｌ酪氨酸的手性识别行为，制备出了β－ＣＤ与Ｌ－酪氨酸（Ｌ－Ｔｙｒ）的固体超分子化合物，并用元素分析、薄层分析、Ｘ射线粉末衍射及热分析对包合物进行了表征，用荧光光谱法测定了包合物的形成常数．实验结果表明，β－ＣＤ具有选择包结Ｌ－酪氨酸的特性；主客体形成１１的包合物，其组成为Ｌ－Ｔｙｒ／β－ＣＤ·１２Ｈ２Ｏ；稳定常数为５．１３×１０３Ｌ／ｍｏｌ；包合物的热稳定性比主客体皆有改善     

The inclusion of rhodium(II)α-methyl-cinnamate in β-cyclodextrin

The preparation and characterization of the 1:1 inclusion compound of rhodium(II) -methyl cinnamate in -cyclodextrin is reported. Evidence of inclusion was obtained from X-ray powder diffraction results, Raman, IR and UV-Vis spectroscopic studies and thermal analysis. Given the potential antitumor activity of the rhodium(II) carboxylate and its virtual insolubility in water, its inclusion in -cyclodextrin opens the possibility for its transference to the aqueous phase.