Morphology and Crystalline Structure of Inclusion Compounds Formed between Poly(ethylene glycol) and Urea

The poly（ethylene glycol） （PEG, with Mw 2000）-urea inclusion compound （IC） crystallized at high temperature region showed two typical orientations, flat-on and edge-on crystals. 2D-XRD and polarized FTIR spectroscopy revealed that the PEG chains within urea channels were perpendicular to the substrate in fiat-on oriented crystals, while PEG chain axes were parallel to the substrate and lay along the growth direction in the edge-on crystals. FT1R absorption bands of PEG in the ICs are sensitive to orientation of the crystals. A scheme of PEG chain packing in the urea IC channel was proposed, which could explain the orientation of the crystal nucleus causing the two types of morphologies. Furthermore, functioning of PEG2000 chain end with analine had significantly influence on the morphology and orientation of the inclusion compound crystals, due to the defects caused by large terminal groups included in the urea channel.

Novel inclusion compounds with urea/thiourea/seleno-urea-anion host lattices

The chemistry of inclusion compounds has a long history and is nowadays a subject of wide-ranging and intense study. With the awarding of the 1987 Nobel Prize in Chemistry to Donald J. Cram, Jean-Marie Lehn and Charles J. Pedersen for their fundamental work on 'host-guest' or 'supramolecular' systems, inclusion chemistry has come to the fore front in contemporary researches. Increasing varieties of novel inclusion compounds and new host molecules have been synthesized recently. The term 'crystal engineering' was coined by Schmidt to describe the rational design and control of molecular packing arrangements in the solid state, and the structural study of clathrates has contributed

Formation and Characteristics of Acrylonitrile/Urea Inclusion Compound

The formation process and composition of the acrylonitrile/urea inclusion compounds （AN/UIC） with different aging times and AN/urea molar feed ratios are studied by differential scanning calorimetry （DSC） and X-ray diffraction （XRD）. It is suggested that DSC can determine the guest/host ratio and the heat of decomposition. Meanwhile, the guest/host ratio and heat of decomposition are obtained, which are 1.17 and 5361.53 J/mol, respec- tively. It is suggested AN molecules included in urea canal lattice may be packed flat against each other. It is found that the formation of AN/UIC depends on the aging time. XRD results reveal that once AN molecules enter urea lattice, AN/UIC are formed, which possess the final structure. When AN molecules are sufficient, the length of AN molecular arrays in urea canals increases as aging time prolonging until urea tunnels are saturated by AN.

Synthesis and Crystal Structure of an Inclusion Compound Constructed through Self-assembly of Nicotinamide and Dicyanamide Coordination Bridges

A novel inclusion compound of [Mn（dca）2（3-nic）2]n·（3-nic）2n（1,dca = dicyanamide,3-nic = nicotinamide） has been prepared and characterized by single-crystal X-ray diffraction,elemental analysis and IR.This complex crystallizes in the triclinic system,space group P1 with a = 7.5979（8）,b = 7.7128（9）,c = 14.5346（17）,α = 100.094（2）,β = 92.444（2）,γ = 116.736（2）o,V = 741.72（15） 3,Z = 1,Dc = 1.512 g/cm3,Mr = 675.55,μ = 0.507 mm-1,F（000） = 347,S = 1.023,the final R = 0.0400 and wR = 0.1010.The inclusion compound is constructed by a three-dimensional host network that consists of dca,3-nic and Mn2＋ with coordination and hydrogen-bonding interactions.In the network,one-dimensional rectangular channels are formed,and the guest molecules（3-nic） are included in the channels.The guest molecules interlink with the host through strong hydrogen bonds.

Inclusion Behavior of Dimer β-CyclodextrinBridged with Aspartic Acid Derivative

The (β-cyclodextrin (CD) dimer bridged with aspartic acid (ASP) derivative, FITC-ASP(NH-(-CD)2 (Host, FITC=fluorescein-4-isothiocyanate), was synthesized. Fluorescence polarization study showed that the novel host formed an inclusion compound, [FITC-ASP(NH-(-CD)2]ATA, for which Kd was determined to be 5.0×10-6 mol/L by Beacon 2000 Analyzer, when ATA (Guest) = Adm-Trp-Arg-Arg-NH2 (Adm = 1-adamantanecarboxylic acid, Trp = tryptophan, Arg = arginine), where Kd is the dissociation constant in aqueous solution at 298 K.

Multiform Host Lattices in the Layer Type Inclusion Compound of Thiourea with Tetrabutylammonium Salicylate and Water

A new inclusion complex thiourea with tetrabutylammonium salicylate and water, 4(C4H9)4N+C7H5O3 ?4(NH2)2CS?2H2O, has been prepared and characterized by X-ray crystallo- graphy. Crystal data: MoKα radiation, triclinic, space group P1 with a = 13.505(5), b = 13.645(5), c = 30.720(10) ?, α = 92.872(7), β = 92.329(7), γ = 92.538(7)°, V = 5643.0(3) ?3, C96H184N12O14S4, Mr = 1858.79, Z = 2, Dc = 1.094 g/cm3, μ = 0.143 mm-1, F(000) = 2040, R = 0.0694 and wR = 0.1282 for 4303 observed reflections with I > 2σ(I). There are three different layer type host-lattices in the crystal structure of the title compound. All of them are formed by [(NH2)2CS·(C7H5O3 )]4 tetramers, but water molecules are located between tetramers and link them by hydrogen bonds to generate ribbons at c = 0 and 1/2, and isolated tetramers are arranged side by side at c = 1/4. The tetrabutylammonium cations are sandwiched between puckered layers.

Two Polymorphs of the Inclusion Compound [(n-C_4H_9)_4N]^+·(C_(13)H_9O_3)^-·H_2O

Two polymorphs of the inclusion compound [（n-C4H9）4N]＋＇（C13H903）H2O have been prepared and characterized by X-ray crystallography. Polymorph 1： triclinic P1, a = 13.4982（2）, b = 13.5743（2）, c = 17.1996（2） A, at = 67.045（1）,β = 77.845（1）, γ= 88.762（1）°, V = 2830.43（7） A3, Z = 4, R = 0.0491, wR= 0.1276; Polymorph 2： tetragonal P43, a = b = 13.53690（1） A, c = 30.8491（8） A, V = 5653.02（16） A3, Z = 8, R = 0.0448, wR = 0.0984. In these two crystal structures, the hydrogen-bonded ribbons built of 4,4＇-dihydroxybenzophenone （DHBP, C13H1003） anions and water molecules are orderly arranged to generate two-dimensional host layers, with tetrabutylammonium cations contained between the layers to form the sandwich-like inclusion compounds. The structures of 1 and 2, which exist as two polymorphs, both display the similar packing pattern and hydrogen-bond linking model.

The Molecular and Crystal Structure of an Inclusion Compound Formed between Acetylferrocene Pyridine-2, 6-diformylhydrazone and Ethanol

: The crystal structure of an inclusion compound formed between acetyl-ferrocene pyridine-2, 6-diformylhydrazone and ethanol was report in the present work.The crystal of C33,H35N5O3Fe2 is monoclinic, space group C2/c with a = 23. 249 (3 ), b=ll. 576(2), c=22. 794(4) A, β=103. 53(l)’, V=5964(1) A3, Mr=66l- 37, Z=8, Dc= 1. 473g/cm3, F (000) = 2752. 00, μ = 10. l5 cm-1. It was found that theethanol molecule present in the crystal lattice depends on the van der Waals force ratherthan hydrogen bonding.

A new approach to the synthesis of N-monosubstituted aniline and its derivatives viaβ-cyclodextrin host-guest complexes

A novel method for the synthesis of N-monosubstituted aniline and its derivatives via β-cyclodextrin （CD） host-guest complexes has been presented. The mild reaction gives the title compounds with high selectivity in good yields of 90-98%.

Binding Affinity of Novel Cyclodextrin Dimers to Ethyl Orange

The interaction between ethyl orange (Eto, guest) and beta-cyclodextrin dimers (1asimilar tod, host) bridged with 2-t-butoxycarbonyl(Boc)-amino diacid was investigated. A remarkable synergic complexation of two cavities in host molecule was observed.

Synthesis and Structure of the Inclusion Compound COF300-ALA

Background and Originality Content,Inclusion single crystals(IsCs)are characterized by the encapsulation of guest molecules within the crystal lattice of a host framework,resulting in,well-defined channels or cavities throughout the material. Host molecules can be broadly di.Videdinto wo main categories.i)The more widespreadgroup is unimolecular inclusion compounds where one host molecule interacts with one guest species.Familiar examples of this cate-gory include calixarenes,cyclodextrins,crown ethers,bai cavitands.cucurbituils,uoaciyclophanes,and various carcerands,ii) the other is multimoiecular inclusion caompounds where two or more host molecules are involved in forming cavities,channels,or layers in the crystal structure to accommodate guest molecules.Host molecules of,this kind include urea,choleic acis,Dianin's compound,etc.,and crystline porous materials such as metal-organic poliyhedrali and porous organic[18]cagesll are well-known examples.

STUDY ON FORMATION MECHANISM OF ADHERING LAYER FORMED ON TOOL FACE

The appearance of adhenng layer formed on tool face, its composition and distributionare analysed when Ca-S free-cutting stainless steel is machined. Cutting temperature field and itsrelation with formation of the layer is also studied. The result shows that, the layer can be formed under proper temperature condition, the stable cutting temperature field keeps the stable layer, itsthickness and composition distribution along rake face depend on the corresponding cutting tem-perature field. The theoretical model of the layer formation is set up.

Homomeric Inclusion and Hydrogen-Bonding Cooperatively Directed Crystalline Assembly of a Cyclotriguaiacylene Derivative with Different Aromatic Acids

Five organic complexes are prepared by cocrystallization of tri-[（N-methyl-2-imidazoly）methoxy]cyclotriguiacylene （TMIM-CTG） with corresponding acids. While hydrogen bonds are the basic interactions in the five complexes, the homo-included motifs with C--H…π interactions also control the molecular arrangement except for complex 5. In complex 1, the two dimensional networks contain 1D zigzag chains formed by hydrogen bonding and 1D chains of homo-included CTG motifs. Complex 2 has 2D 4.82 hydrogen bonding networks, and the chains of homomeric inclusion extend the 2D structure to a 3D framework. Complex 3 contains four-membered rings through hydrogen bonds, and the chains of homo-inclusion link the rings to a novel 2D network. In complex 4, hydrogen bonds construct a novel double-layer 2D network, which is extended to a 3D framework by ＂hand-shake＂ dimeric homomeric inclusion interactions. Interestingly, there is no homomeric inclusion phenomenon in complex 5 and hydrogen bonds solely connect two components to a chiral （6,3） 2D network.

Study on the inclusion compound of β-cyclodextrin with (η5-cyclopentadienyl)tricarbonylmanganese(0)

The supramolecular inclusion compound of β-cyclodextrin (β-CD, host) with (η5-cyclopentadienyl)tricarbonylmanganese [MnCp(CO)3, guest] was obtained in a crystalline state. The host-guest compound is thermally stable and do not liberate the guest on heating at 100$ in vacuum. It was characteried by elemental analysis,1H NMR, differential scanning thermal (DSC) analysis and TLC. Continueous variation plot by NMR method shows that β-CD formed 1:1 inclusion compound with MnCp(CO)3. On the basis of 1H NMR spectra and the model building with Corey Pauling Koltum (CPK) models, the most probable inclusion mode is proposed.