The structure of the mineralomimetic cadmium cyanide-dimethyl carbonate clathrate

Cd(CN)₂·(CH₃O)₂CO (1) contains a mineralomimetic framework of Cd(CN)₂ analogous to the low temperature form of cristobalite. The host framework is isostructural to those of previously reported Cd(CN)₂·G compounds (G = CHCl₂CH₂Cl2, (CH₃)₂CHBr3). The dimethyl carbonate molecules in the adamantane-like cage display orientation disorder associated with the location of the carbonyl oxygen atom.Presented at the Sixth International Seminar on Inclusion Compounds, Istanbul, Turkey, 27–31 August, 1995.     

Nesting inclusion compounds. The X-ray structure of the 15-crown-5 sodium diphenylethyl diphenylmethyl cyanoacetonate complex

The action of sodium cyanide ongem -diphenyl-chloropropanone under phase transfer conditions in the presence of 15-crown-5 yields the title compound as a minor product. The crystal structure of this complex reveals that, in the solid state, the [15-crown-5-Na⁺] guest species is found within a loose cage of diphenylethyl diphenyl cyanoacetonate molecules with one open side of the cage blocked by an adjacent 15-crown-5 molecule. Colourless crystals of the compound belong to the monoclinic space groupP21/n witha = 12,255(2) Å,b = 13,005(1) Å,c = 23,433(2) Å, = 95,92(1) ° andD _c = 1.23 g cm^–3 forZ = 4.     

Crystal structure analysis of the carbon tetrabromide clathrate of hexakis(phenylseleno)benzene

The 12 inclusion compound of hexakis(phenylseleno)benzene (1) with CBr₄ is trigonal, space groupR , witha=14.474(3),c=21.487(4) Å, and three host and six guest molecules in a unit cell referred to hexagonal axes. A true clathrate structure is found and in each closed cage there are two carbon tetrabromide guest molecules, orientated such that a C–Br bond of each is colinear with thec-axis of the crystal. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82002. To obtain copies, see page ii of this issue.     

Reorganization of the structures,morphologies, and conformations of bulk polymers via coalescence from polymer–cyclodextrin inclusion compounds

Bulk poly(ethylene terephthalate) (PET) and bisphenol A polycarbonate (PC) samples have been produced by the coalescence of their segregated, extended chains from the narrow channels of the crystalline inclusion compounds (ICs) formed between the γ‐cyclodextrin (CD) host and PET and PC guests, which are reported for the first time. Differential scanning calorimetry, Fourier transform infrared, and X‐ray observations of PET and PC samples coalesced from their crystalline γ‐CD‐ICs suggest structures and morphologies that are different from those of samples obtained by ordinary solution and melt processing techniques. For example, as‐received PC is generally amorphous with a glass‐transition temperature (T_g) of about 150 °C; when cast from tetrahydrofuran solutions, PC is semicrystalline with a melting temperature (T_m) of about 230 °C; and after PC/γ‐CD‐IC is washed with hot water for the removal of the host γ‐CD and for the coalescence of the guest PC chains, it is semicrystalline but has an elevated T_m value of about 245 °C. PC crystals formed upon the coalescence of highly extended and segregated PC chains from the narrow channels in the γ‐CD host lattice are possibly more chain‐extended and certainly more stable than chain‐folded PC crystals grown from solution. Melting the PC crystals formed by coalescence from PC/γ‐CD‐IC produces a normal amorphous PC melt that, upon cooling, results in typical glassy PC. PET coalesced from its γ‐CD‐IC crystals, although also semicrystalline, displays a T_m value only marginally elevated from that of typical bulk or solution‐crystallized PET samples. However, after the melting of γ‐CD‐IC‐coalesced PET crystals, it is difficult to quench the resultant PET melt into the usual amorphous PET glass, characterized by a T_g value of about 80 °C. Instead, the coalesced PET melt rapidly recrystallizes during the attempted quench, and so upon reheating, it displays neither a T_g nor a crystallization exotherm but simply remelts at the as‐coalesced T_m. This behavior is unaffected by the coalesced PET sample being held above T_m for 2 h, indicating that the extended, unentangled nature of the chains in the noncrystalline regions of the coalesced PET are not easily converted into the completely disordered, randomly coiled, entangled melt. Apparently, the highly extended, unentangled characters of the PC and PET chains in their γ‐CD‐ICs are at least partially retained after they are coalesced. Initial differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared, and X‐ray observations are described here. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 992–1012, 2002     

The structure of the 1,4-butanediol clathrate of a bis-ammonium salt of azulene

The X-ray structure of the 1,4-butanediol clathrate ofN,N-[1,3-azulenylenebis(methylene)]bis(trimethyl-ammonium)-diiodide is described, and the differences as well as the similarities to the 1-butanol inclusion of the same host are discussed in detail. The unit cell data of further clathrates of this new type are quoted.Supplementary Data. Details of the crystal structure are available on request from the Fachinformationszentrum Energie-Physik-Mathematik, D-7515 Eggenstein, Leopoldshafen 2, by quoting the depository number CSD50482, the names of the authors, and the journal citation     

A new host compound for the selective inclusion of ethanol

A new host compound of the onium salt type,N-(3-biphenylmethyl)quininium bromide (1), is described. This host compound shows an unusually high selectivity for the inclusion of ethanol. Using this clathrand, ethanol can be extracted from a variety of solvent mixtures. In most cases, a remarkable enrichment of the ethanol is observed. The following solvents in a mixture with ethanol remain in the mother liquid: methanol,n-propanol,n-hexane, pyridine.     

Thermoanalytical investigation of the guest-release process in aromatic-guest clathrates of three-dimensional metal complex hosts

The guest-release process was investigated in terms of the activation energy evaluated by thermogravimetry for the en-Td-type clathratescatena--[catena--(ethylenediamine)cadmium(II) tetra--cyanocadmate(II) or -mercurate(II)]-benzene(1/2), -benzene-d ₆(1/2), and -pyrrole(1/2), the Hofmannen-type clathratescatena-[catena--(ethylenediamine)cadmium(II) tetra--cyanonickelate(Il)]-benzene (1/2) and -pyrrole(1/2), the Hofmann-pn-type clathratecatena-[catena--(dl- orl-propylenediamine (cadmium(II) tetra--cyanonickelate(II)]-pyrrole(2/3), and the pn-Td-type clathratescatena-[catena--(dl-propylenediamine) or -(l-propylenediamine)cadmium(II) tetra--cyanocadmate(II)]-benzene(2/3). Values of the activation energy are correlated with the structural change in the metal complex host accompanied by the release of the guest molecules. The crystal structure ofcatena-[ethylenediaminecadmium tetra--cyanonickelate(II)], the residual host of the Hofmann-en-type, has been analyzed to elucidate the correlation.     

球形主体分子的包结性能及其在制备有机非线性光学材料 中的应用

提出了球形主体分子的设计思想,把具有球形结构的分子柏木醇(1)、马钱子碱(2)、三乙烯二胺(1,4-二氮-二环[2.2.2]辛烷(3)作为主体分子,把酚类化合物,诸如苯酚(4)、邻甲苯酚(5)、间甲苯酚(6)、对甲苯酚(7)、对氯苯酚(8)和对硝基苯酚(11)等作为客体分子,进行了主客体分子相素作用实验,采用粉末X射线衍射、1^HNMR等分析手段确认了包结化合物的形成及主客体分子的摩尔比,摩尔比(H/G)分别为(1)+(4)1:1,(1)+(5)1:1,(1)+(6)1:1,(1)+(7)1:1,(1)+(11)1:2,(2)+(11)1:1,(3)+(4)1:2,(3)+(5)1:3,(3)+(6)1:2,(3)+(7)1:2,(3)+(8)1:2,(3)+(11)1:2,对典型包结化合物的单晶,诸如柏木醇和邻甲苯酚、马钱子碱和对硝基苯酚以及三乙烯二胺和对硝基苯酚,进行了四圆X射线衍射结构分析,结果表明,包结化合物的堆砌结构特征随主体分子的体积大小而改变,从隧道型如(1)+(5)和(2)+(11)转变为夹层型如(3)+(11)。用Nd:YAG激光测试晶体的SHG效应,结果表明,大部分包结物晶体具有非线性光学性质。     

(S, R)联萘酚磷酰胺包合物的合成及晶体结构

本文合成了主体分子(S, R)-1, 1'-联萘-2, 2'-二羟基磷酰(N-α-苯乙基)胺及8种包合物, 经熔点、结晶形状及元素分析确定了它们的组成; 并经过X-射线衍射分析确定了其乙醇包合物的单晶结构, 晶体属单斜晶系, 空间群P2~1,a=0.9365(1)nm, b=1.2825(7)nm, c=1.1640(3)nm, β=111.71°, Z=2,R=0.0469。其中主体分子形成层状结构, 客体分子处于相邻的层间。     

Binding propensity and selectivity of cationic,anionic, and neutral guests with model hydrophobic hosts: A first principles study

Computations play a critical role in deciphering the nature of host–guest interactions both at qualitative and quantitative levels. Reliable quantum chemical computations were employed to assess the nature, binding strength, and selectivity of ionic, and neutral guests with benzenoid hosts. Optimized complex structures reveal that alkali and ammonium ions are found to be in the hydrophobic cavity, while halide ions are outside, while both complexes elicit substantial binding energy. The origin of the selectivity of host toward the guest has been traced to the interaction and deformation energies, and the nature of associated interactions is quantified using energy decomposition and the Quantum Theory of Atoms in Molecules analyses. While the larger hosts lead to loosely bound complexes, as assessed by the longer intermolecular distances, the binding strengths are proportional to the size of the host systems. The binding of cationic complexes is electrostatic or polarization driven while exchange term dominates the anionic complexes. In contrast, dispersion contribution is a key in neutral complexes and plays a pivotal role in stabilizing the polyatomic complexes.     

Clathrates of organic onium halides,V: preparation of new clathrates and structure of the 1-propanol inclusion of a bis-quinuclidinium salt

Organic onium salts (3–15) are prepared and their inclusion capacity towards solvent molecules is investigated. The crystal structure of the1·propanol·H₂O clathrate ofN,N-[5-tert-butyl-1,3-phenylenebis(methylene)]bis(quinuclidinium)dibromide (4) is reported and compared with the X-ray structures of related clathrates described earlier. Supplementary Data: Details of the crystal structure are available on request from the Fachinformationszentrum Energie-Physik-Mathematik, D-7517 Eggenstein, Leopoldshafen 2, by quoting the depository number CSD 50883, the names of the authors, and the journal citation.     

NMR characterization of the host-guest inclusion complex between beta-cyclodextrin and doxepin

The interaction between doxepin, a member of the tricyclic antidepressant (TCA) class of drugs, with beta-cyclodextrin (beta-CD) was investigated using NMR. Several TCAs have been reported to form a complex with beta-CD having 1:1 stoichiometry. Previous results from UV-visible spectroscopy, fluorescence measurements, and molecular modeling indicated that for imipramine, desipramine, and amitriptyline, the TCA aliphatic tail is included in the cyclodextrin cavity with apparently no interaction of the tricyclic ring. An alternative view of the doxepin-beta-CD complex is presented in this work using analysis of complexation-induced chemical shifts (CICSs), the method of continuous variation (Job's analysis), and analysis of ROESY spectra. The Job's plot derived from the NMR spectral data confirms that the complex formed has 1:1 stoichiometry. The largest changes in the CICS data were observed for the aromatic protons of one of the doxepin rings, with much smaller chemical shift changes observed for the protons of the other aromatic ring and the doxepin tail. Perhaps the most significant evidence for inclusion of the doxepin tricyclic ring is the strong ROESY cross peaks between the doxepin aromatic resonances and the protons located inside the beta-CD cavity. Changes in the doxepin (1)H NMR spectrum and the behavior of ROESY exchange cross peaks suggest that inclusion complex formation decreases the rate of internal motions of doxepin.     

Novel series of clathrate compounds of the three-dimensional metal complex hosts (N-methyl-1,3-diaminopropane)cadmium(II) tetracyanonickelate(II), (N,N-Dimethyl-1,3-diaminopropane)cadmium(II) Tetracyanonickelate(II), and (2-Hydroxyethylmethylamine) cadmium(II) Tetracyanonickelate(II)

The clathrate compounds of the title three-dimensional metal complex hosts have been prepared with various aliphatic, alicyclic, and aromatic guest molecules. The typical structure has been demonstrated for a cyclohexane clathrate (N-methyl-1,3-diaminopropane)cadmium(II) tetracyanonickelate(II)-cyclohexane(2/1) by X-ray single crystal analysis. The powder X-ray diffraction data were assigned for the other clathrates to the tetragonal systems isostructural to the cyclohexane clathrate in which the box-like cavity with the approximate dimensions of 7 × 7 × 5 ų accommodates the guest molecule.     

Crystal structure of tetraethylammonium fluoride-water (4/11), 4(C2H5)4N+F− · 11H2O,a clathrate hydrate containing linear chains of edge-sharing (H2O)4F− tetrahedra and bridging water molecules

Crystals of 4(C₂H₅)₄N⁺F^– · 11H₂O are orthorhombic, space groupPna2₁, witha=16.130(3),b=16.949(7),c=17.493(7) Å, andZ=4. The structure was shown to be a clathrate hydrate containing infinite chains of edge-sharing (H₂O)₄F^– tetrahedra extending parallel to thea axis. The chains are laterally linked by bridging water molecules to form a three-dimensional hydrogen-bonded anion/water framework. The ordered (C₂H₅)₄N⁺ cations occupy the voids in two open channel systems running in theb andc directions. FinalR _F =0.091 for 2278 observed MoK data measured at 22°C. Supplementary Data: relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82010 (20 pages).Dedicated to Professor H. M. Powell.     

Crystal structures of the clathrate inclusion compounds formed by the host bis(isothiocyanato) tetrakis (4-methylpyridine) iron (II) with benzene,m-xylene andp-xylene as guests

Single crystal X-ray structures of three 1 : 1 (guest: host) compounds in which the Fe(NCS)₂ (4-methylpyridine)₄ complex is the host component and benzene,m-xylene andp-xylene are the respective guest components, are reported. The crystals of the inclusion compounds are tetragonalI4₁/a, with:a = 17.08(1),c = 23.66(3) Å (benzene clathrate);a = 17.17(1),c = 24.02(2) Å (m-xylene clathrate) anda = 17.12(1),c = 23.93(3) Å (p-xylene clathrate);Z = 8. The host complex molecule has the octahedral type of coordination of the N₆ donor system. The isothiocyanate ligands are intrans positions and related by twofold axial symmetry. The symmetry axis runs diagonally between the neighbouring, equatorial 4-methylpyridine (MePy) ligands. The two symmetrically independent McPy ligands form angles ofca. 45 and 55° with the equatorial Fe-N₄ plane. The absorption sites for guest molecules lie on centres of symmetry. Non-centrosymmetricm-xylene molecules occupy these sites randomly distributed over two orientations related by symmetry. The structures belong to the class oforganic zeolites since the cavities occupied by the guest molecules are interconnected to form a three-dimensional network.     

Microwave synthesis,structure, and properties of molybdophosphate compounds

Two compounds of disphosphopentamolybdate(VI) with the formulae (C₄H₁₄N₂O)₃- [P₂Mo₅O₂₃]?·?3H₂O (1) and (C₄H₁₄N₂O)₅(NH₄)₂[P₂Mo₅O₂₃]₂?·?5H₂O (2) have been synthesized by a simple, fast and efficient microwave method, and their crystal structures and spectroscopic properties have been studied. The heteropoly anion [P₂Mo₅O₂₃]^6? has a known structure built of five MoO₆ octahedra and two PO₄ tetrahedra. The MoO₆ octahedra form a pentagonal ring by sharing four edges and one corner and the PO₄ tetrahedra are attached to one side of the ring by three oxygen atoms. The most interesting feature of compound 1 is its extensive framework based on a one-dimensional zigzag chain. In compound 2, a more extensive and complicated framework of hydrogen bonds joins the anions, organic cations and water molecules together.     

Small-ring inclusion hosts. 4. X-ray crystal structures oftrans-3,3-Bis(4-methylphenyl)cyclopropane-1,2-dicarboxylic acid and of its inclusion complex with Dimethyl Sulphoxide (1:2)

The crystal structures of the unsolvatedtrans-3,3-bis(4-methylphenyl)cyclopropane-1,2-dicarboxylic acid (1) and of its inclusion compound with dimethyl sulphoxide,1·DMSO (1:2), have been studied by X-ray diffraction. Crystals of1 show triclinic symmetry (P ) withZ = 4 and the unit cell dimensionsa = 7.617(2),b = 15.321(4),c = 15.297(3) Å, = 109.76(2), = 103.47(1), = 89.87(2)°. FinalR = 0.037 for 3601 reflections collected atT = 153(1) K. Crystals of1·DMSO (1: 2) are monoclinic (P2₁/n) withZ = 4 and cell dimensionsa = 10.744(1),b = 10.806(1),c = 21.302(2) Å, = 101.68(1)°. The clathrate structure was refined toR = 0.034 for 1671 reflections obtained atT = 173(1) K. In the unsolvated host compound cyclic pairs of O-H ... bonds, commonly observed in carboxylic acids, couple the carboxylic functions two by two, thus giving rise to endless chains due to the bifunctionality and thetrans position of the acid groups of1. The complex with DMSO as guest, however, consists of distinct hydrogen-bonded 1:2 host-guest associates, held together by weak intermolecular interactions.Supplementary Data relating to this article have been deposited with the British Library at Boston Spa, Wetherby, West Yorkshire, U.K., as Supplementary Publication No. SUP 82139 (32 pages).For Part 3, see Reference [1].     

Crystalline inclusion compounds of a new diol host featuring a combination of anthracene and 9-fluorenol units

The diol host compound 2 has been synthesised and its behaviour to form crystalline inclusion compounds is discussed in comparison with an analogous ethynylene spaced host compound 1. The rotation around the fluorenol–anthracene bonds in 2 is highly restricted as indicated by solution NMR spectroscopy, molecular mechanics and semi-empirical calculations. Single-crystal X-ray structures of the inclusion complexes of 2 with 1-BuOH (2a), morpholine/H₂O (2b) and DMSO (2c) are in agreement with the bent geometry of the anthracene ring system suggested by the calculations. The structures exhibit specific modes of hydrogen bond interactions.     

The stabilization of thermodynamically disfavoured conformers of chlorocyclohexane in the host lattice of tri-ortho-thymotide. Crystallographic and infrared spectroscopic studies

The clathrate compounds of tri-o-thymotide have been prepared with chlorocyclohexane, bromocyclohexane and 2-chlorotetrahydropyran. The cage-type inclusion complex C₃₃H₃₆O₆ · ₂ ¹ C₆H₁₁Cl (trigonal,P3₁21,a=13.604(1),c=30.605(1) Å,Z=6) contains an axial-Cl chair and an axial-Cl boat conformation of the guest, distributed statistically in the ratio 2 1 over the available sites. The observed conformations have been compared with conformers calculated by force field methods. IR spectra are consistent with the crystal structure results for the tri-o-thymotide/chlorocyclohexane clathrate. They further demonstrate the similar preferential inclusion of axial isomers of bromocyclohexane and 2-chlorotetrahydropyran. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82023 (16 pages).Dedicated to Professor H. M. Powell.