Articles de revues : « Host - guest inclusion complexes »

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Mejuto, Juan C., et Jesus Simal-Gandara. « Host–Guest Complexes ». International Journal of Molecular Sciences 23, n^o 24 (12 décembre 2022) : 15730. http://dx.doi.org/10.3390/ijms232415730.

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Malinska, Maura. « Insights into molecular recognition from the crystal structures of p-tert-butylcalix[6]arene complexed with different solvents ». IUCrJ 9, n^o 1 (16 novembre 2021) : 55–64. http://dx.doi.org/10.1107/s2052252521010678.

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Calixarenes are host molecules that can form complexes with one or more guest molecules, and molecular recognition in calixarenes can be affected by many factors. With a view to establishing molecular recognition rules, the host p-tert-butylcalix[6]arene (TBC6) was crystallized with different guest molecules (cyclohexane, anisole, heptane, toluene, benzene, methyl acetate, ethyl acetate, dichloromethane, tetrahydrofuran and pyridine) and the obtained structures were characterized by X-ray diffraction. With most solvents, 1:1 and/or 1:3 host–guest complexes were formed, although other stoichiometries were also observed with small guest molecules, and crystallization from ethyl acetate produced the unsolvated form. The calculated fill percentage of the TBC6 cavity was ∼55% for apolar guests and significantly lower for polar solvents, indicating that polar molecules can bind to apolar cavities with significantly lower packing coefficients. The most stable crystals were formed by 1:1 host–guest inclusion complexes. The ratio between the apolar surface area and the volume was used to predict the formation of inclusion versus exclusion complexes, with inclusion complexes observed at ratios <40. These findings allow the binding of potential guest molecules to be predicted and a suitable crystal packing for the designed properties to be obtained.

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Toda, Fumio. « Crystalline inclusion complexes as media of molecular recognitions and selective reactions ». Pure and Applied Chemistry 73, n^o 7 (1 juillet 2001) : 1137–45. http://dx.doi.org/10.1351/pac200173071137.

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Hexaol host compounds which include guest molecules maximum in 1:6 ratio were prepared. Aromatic hexaol host, hexahydroxytriphenylene, was found to form chiral inclusion crystal by complexation with achiral guest molecules. Some interesting and important optical resolutions of rac-guests by inclusion complexation with a chiral host were described. When chemical reaction and the inclusion complexation procedures in a water suspension medium are combined, new economical and ecological method of the preparation of optically active compound can be established. When photochemical reactions are carried out in an inclusion crystal with a chiral host, enantioselective reactions occur, and optically active product can be obtained. Several successful reactions are described.

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Kadu, Rahul, Vineeta Pillai, Amrit V. et Vinay K. Singh. « Synthesis and spectral characterization of bimetallic metallomacrocyclic structures [MII2-μ2-bis-{(κ2S,S-S2CN(R)C6H4)2O}] (M = Ni/Zn/Cd) : density functional theory and host–guest reactivity studies ». RSC Advances 5, n^o 129 (2015) : 106688–99. http://dx.doi.org/10.1039/c5ra22175g.

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Hettiarachchi, D. Saroja N., et Donal H. Macartney. « Cucurbit[7]uril host-guest complexes with cationic bis(4,5-dihydro-1H-imidazol-2-yl) guests in aqueous solution ». Canadian Journal of Chemistry 84, n^o 6 (1 juin 2006) : 905–14. http://dx.doi.org/10.1139/v06-099.

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The host–guest interactions between cucurbit[7]uril and a series of novel cationic bis(4,5-dihydro-1H-imidazol-2-yl)arene and 1-(4,5-dihydro-1H-imidazol-2-yl)- and 1,3-bis(4,5-dihydro-1H-imidazol-2-yl)-adamantane guests have been investigated in aqueous solution using UV–vis and NMR spectroscopy, and electrospray mass spectrometry. With the exception of the 1,3-bis(4,5-dihydro-1H-imidazol-2-yl)adamantane (which binds externally to the CB[7]), these guests form very stable inclusion complexes with slow exchange on the 1H NMR timescale. The direction and magnitude of the complexation-induced shifts (CIS) in the proton resonances of the guests are indicative of the residence of the hydrophobic core of the guest within the CB[7] cavity and the charged 4,5-dihydro-1H-imidazol-2-yl units outside the cavity adjacent to the carbonyl-lined portals of the host. The CIS values and the inclusion stability constants have been correlated with the nature of the guest core and with the distance between the charges on the terminal 4,5-dihydro-1H-imidazol-2-yl rings.Key words: cucurbit[7]uril, host–guest complex, dihydroimidazolyl, inclusion stability constants.

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Zhang, Meng, Nicolas Levaray, Josée R. Daniel, Karen C. Waldron et X. X. Zhu. « Cholic acid dimers as invertible amphiphilic pockets : synthesis, molecular modeling, and inclusion studies ». Canadian Journal of Chemistry 95, n^o 7 (juillet 2017) : 792–98. http://dx.doi.org/10.1139/cjc-2016-0621.

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Two dimers of cholic acid were synthesized through simple covalent linkers. The dimers form invertible molecular pockets in media of different polarity; hydrophobic pockets are formed in water and hydrophilic pockets are formed in organic media. Fluorescence studies show that pockets formed by these dimers can serve as invertible hosts for the hydrophobic guest pyrene and the hydrophilic guest coumarin 343. The molecular pocket also enhances dissolution of the weakly soluble cresol red sodium salt in organic media. Molecular modeling was performed to better understand the host–guest complexation process of the invertible amphiphilic pockets. The calculated free energy changes indicate that the two dimers form the most stable complexes with coumarin 343 at a host to guest ratio of 2:2, whereas the host to guest ratio differs in the formation of complexes with pyrene for the two dimers. The dimer with the shorter, less flexible linker seems to form host–guest complexes that are more stable in both water and organic solvents.

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Suwinska, Kinga. « Intermolecular interactions in inclusion complexes ». Acta Crystallographica Section A Foundations and Advances 70, a1 (5 août 2014) : C673. http://dx.doi.org/10.1107/s2053273314093267.

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The whole range of interactions can be found between host and guest in supramolecular assemblies from ion-ion interactions, ion-dipole interactions, dipol-dipol interactions through hydrogen bonding, cation-π interactions, π-π stacking to van der Waals forces. Additionally, the same interactions exist between the supramolecular complex and its surrounding, i.e. solvent molecules, neighboring complexes, gases, etc. Recently the interest of scientists in the field of supramolecular chemistry is focused on design and synthesis of water-soluble synthetic macrocyclic ligands which are good receptors for biologically important guest molecules and can mimic the models of biological systems. Studying such complexes may provide new insight into the mechanisms of the formation of similar natural systems and as a consequence will help in better understanding the processes which occur in biological systems and in developing new materials with specific properties and functions. In this presentation the interactions which are stabilizing inclusion complexes of calix[n]arenes and cyclodextrins (host molecules) with guest molecules of biological interest, especially drug molecules will be discussed. This research was partly financed by the European Union within the European Regional Development Fund (POIG.01.01.02-14-102/09)

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Gómez-González, Borja, Luis García-Río, Nuno Basílio, Juan C. Mejuto et Jesus Simal-Gandara. « Molecular Recognition by Pillar[5]arenes : Evidence for Simultaneous Electrostatic and Hydrophobic Interactions ». Pharmaceutics 14, n^o 1 (28 décembre 2021) : 60. http://dx.doi.org/10.3390/pharmaceutics14010060.

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The formation of inclusion complexes between alkylsulfonate guests and a cationic pillar[5]arene receptor in water was investigated by NMR and ITC techniques. The results show the formation of host-guest complexes stabilized by electrostatic interactions and hydrophobic effects with binding constants of up to 107 M−1 for the guest with higher hydrophobic character. Structurally, the alkyl chain of the guest is included in the hydrophobic aromatic cavity of the macrocycle while the sulfonate groups are held in the multicationic portal by ionic interactions.

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Liu, Yu, Chang-Cheng You, Takehiko Wada et Yoshihisa Inoue. « Effect of Host Substituent upon Inclusion Complexation of Aliphatic Alcohols with Organoseleno β-Cyclodextrins ». Journal of Chemical Research 2000, n^o 2 (février 2000) : 90–92. http://dx.doi.org/10.3184/030823400103166490.

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The effect of self-including host substituent upon the inclusion complexation of arylseleno β-cyclodextrins with alkanol guests has been investigated in aqueous buffer solution at 25°C, by using spectropolarimetric titrations, and the results show that the stability constants of the host–guest complexes formed are correlated with the Hammett's σ value of the host's substituent.

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Fu, T. Y., J. R. Scheffer et J. Trotter. « Structures and Photochemistry of Inclusion Compounds of 9,10-Dihydro-9,10-ethenoanthracene-11,12-bis(diphenylmethanol) ». Acta Crystallographica Section B Structural Science 53, n^o 2 (1 avril 1997) : 300–305. http://dx.doi.org/10.1107/s0108768196013614.

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Crystal structures have been determined for inclusion complexes of the host molecule 9,10-dihydro-9,10-ethenoanthracene-11,12-bis(diphenylmethanol), with acetone, ethanol and toluene as guest solvent molecules. The host molecule exhibits an intramolecular O--H...O hydrogen bond in each of the complexes, with intermolecular hydrogen bonds to the acetone and ethanol guests. Different photoproducts are obtained from solution and solid-state photolyses; the solid-state reaction involves a relatively small amount of molecular rearrangement, for which a mechanism is proposed.

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Dutta, Ashutosh, Niloy Roy, Koyeli Das, Debadrita Roy, Raja Ghosh et Mahendra Nath Roy. « Synthesis and Characterization of Host Guest Inclusion Complexes of Cyclodextrin Molecules with Theophylline by Diverse Methodologies ». Emerging Science Journal 4, n^o 1 (1 février 2020) : 52–72. http://dx.doi.org/10.28991/esj-2020-01210.

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Steady host–guest inclusion complexes have been produced with medicinally important guest molecule theophylline within aqueous α-Cyclodextrin and HP-β-Cyclodextrin. α-and HP-β-Cyclodextrins have been established with favorable structural features for inclusion with Theophylline which include diversified applications in modern science such as controlled delivery in the field of pharmaceuticals, food processing, pesticides, foodstuffs etc. Theophylline is one of the most widely accepted drugs for the treatment of asthma and chronic obstructive pulmonary disease (COPD) worldwide, even if it has been used clinically for many years. With both α and HP-β-Cyclodextrins it is found that 1:1 hosts-guest inclusion complexes are formed with the guest molecule theophylline. The construction and quality of the inclusion complexes have been characterized by using conductivity measurement, surface tension study, and Job’s method. The inclusion phenomenon has been confirmed by FTIR spectroscopy, proton NMR study. Association constants and thermodynamic parameters have been evaluated for the created inclusion complexes by ultraviolet spectroscopy.

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Russo, Marco, et Paolo Lo Meo. « Binding abilities of a chiral calix[4]resorcinarene : a polarimetric investigation on a complex case of study ». Beilstein Journal of Organic Chemistry 13 (15 décembre 2017) : 2698–709. http://dx.doi.org/10.3762/bjoc.13.268.

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Polarimetry was used to investigate the binding abilities of a chiral calix[4]resorcinarene derivative, bearing L-proline subunits, towards a set of suitably selected organic guests. The simultaneous formation of 1:1 and 2:1 host–guest inclusion complexes was observed in several cases, depending on both the charge status of the host and the structure of the guest. Thus, the use of the polarimetric method was thoroughly revisited, in order to keep into account the occurrence of multiple equilibria. Our data indicate that the stability of the host–guest complexes is affected by an interplay between Coulomb interactions, π–π interactions, desolvation effects and entropy-unfavorable conformational dynamic restraints. Polarimetry is confirmed as a very useful and versatile tool for the investigation of supramolecular interactions with chiral hosts, even in complex systems involving multiple equilibria.

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Giastas, Petros, Konstantina Yannakopoulou et Irene M. Mavridis. « Molecular structures of the inclusion complexes β-cyclodextrin–1,2-bis(4-aminophenyl)ethane and β-cyclodextrin–4,4′-diaminobiphenyl ; packing of dimeric β-cyclodextrin inclusion complexes ». Acta Crystallographica Section B Structural Science 59, n^o 2 (26 mars 2003) : 287–99. http://dx.doi.org/10.1107/s010876810300257x.

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The present investigation is part of an ongoing study on the influence of the long end-functonalized guest molecules DBA and BNZ in the crystal packing of β-cyclodextrin (βCD) dimeric complexes. The title compounds are 2:2 host:guest complexes showing limited host–guest hydrogen bonding at the primary faces of the βCD dimers. Within the βCD cavity the guests exhibit mutual π...π interactions and between βCD dimers perpendicular NH...π interactions. The DBA guest molecule exhibits one extended and two bent conformations in the complex. The BNZ guest molecule is not planar inside βCD, in contrast to the structure of BNZ itself, which indicates that the cavity isolates the molecules and forbids the π...π stacking of the aromatic rings. NMR spectroscopy studies show that in aqueous solution both DBA and BNZ form strong complexes that have 1:1 stoichiometry and structures similar to the solid state ones. The relative packing of the dimers is the same in both complexes. The axes of two adjacent dimers form an angle close to 20° and have a lateral displacement ≃2.45 Å, both of which characterize the screw-channel mode of packing. Although the βCD/BNZ complex indeed crystallizes in a space group characterizing the latter mode, the βCD/DBA complex crystallizes in a space group with novel dimensions not resembling any of the packing modes reported so far. The new lattice is attributed to the three conformations exhibited by the guest in the crystals. However, this lattice can be transformed into another, which is isostructural to that of the βCD/BNZ inclusion complex, if the conformation of the guest is not taken into account.

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Barman, Biraj Kumar, Kanak Roy et Mahendra Nath Roy. « Probing Inclusion Complexes of Pentoxifylline and Pralidoxim inside Cyclic Oligosaccharides by Physicochemical Methodologies ». Zeitschrift für Physikalische Chemie 233, n^o 8 (27 août 2019) : 1109–27. http://dx.doi.org/10.1515/zpch-2017-1020.

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Abstract Structurally different Molecules namely Pentoxifylline and Pralidoxim were chosen along with α-cyclodextrin and β-cyclodextrin to study host-guest inclusion phenomena. The formations of host guest inclusion complexes were confirmed by studying 1H-NMR spectra, FT-IR spectra, apparent molar volume and viscosity co-efficient. The stabilities of inclusion complexes were compared calculating the binding constant from UV-VIS spectroscopic study. The 1:1 stoichiometry of the inclusion complexes were also determined by analysing the Jobs plot and surface tension data. The values for Gibbs’ free energy were found negative for both the processes. Based on all the above experiments the inclusion processes were found feasible for both the compounds. These types of inclusion complexes are of high interest in the field of research and industry as these are used as drug delivery systems.

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Wilson, Lee D., et Ronald E. Verrall. « A 1H NMR study of cyclodextrin - hydrocarbon surfactant inclusion complexes in aqueous solutions ». Canadian Journal of Chemistry 76, n^o 1 (1 janvier 1998) : 25–34. http://dx.doi.org/10.1139/v97-208.

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A 1H NMR chemical shift ( delta ) study of a homologous series of hydrocarbon (hc) (CxH2x + 1CO2Na, x = 5, 7, 9, 11, 13) surfactants (S) has been carried out in water and in binary solvent (D2O + cyclodextrin (CD)) systems at 22°C. Complementary 1H NMR chemical shift ( delta ) data of the cyclodextrins in binary (D2O + S) systems containing hc surfactants have also been obtained. Complex induced shift (CIS) values for selected host or guest protons were found to increase as the alkyl chain (Cx) length of the surfactant increased. The CIS values are found to depend on the following factors: (i) the magnitude of the binding constant (Ki, i = 1:1, 2:1), (ii) the chain length of the surfactant, (iii) the mole ratio of the host to guest species, (iv) the host-guest stoichiometry, and (v) the host-guest inclusion geometry. The CIS values of the CD-S systems have been analyzed using equilibrium models in which 1:1 complexes, 1:1 plus 2:1 complexes, and uncomplexed species are present. Differences in the binding affinity, stoichiometry, and inclusion geometry of the complexes formed between a given hc surfactant and the various cyclodextrins were observed.Key words: cyclodextrin, surfactant, NMR, chemical shift, complex, binding constant.

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Boland, Patricia G., Sara J. Accardi, Carrie A. Snow et Brian D. Wagner. « Investigations of the supramolecular host properties of a fluorescent bistren cage compound ». Canadian Journal of Chemistry 87, n^o 2 (février 2009) : 448–52. http://dx.doi.org/10.1139/v08-179.

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The host properties of a bistren cage compound, previously reported to be an efficient anion sensor, are shown to include encapsulation of small aromatic guest molecules. It is also shown that the intrinsic fluorescence of this cage compound, arising from the anthracenyl moiety in its structure, is sensitive to the encapsulation of aromatic guests in aqueous solution and can be used to measure the binding constants for any such guest. This makes this bistren cage a rare example of a fluorescent host for aromatic guests, and suggests potential applications of this compound as a versatile fluorescent sensor for a variety of guests of interest. The binding of a number of benzene derivatives was studied; these were all found to form 1:2 host–guest inclusion complexes with a wide range in total binding constants (K1K2), from 6.4 × 103 to 3.5 × 107 (mol/L)–2, indicating a significant degree of selectivity for different benzene derivatives. The binding strength was found to depend on both the guest polarity and aqueous solubility.

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Rodríguez, Silvio D., et Delia L. Bernik. « Host–Guest Molecular Interactions in Vanillin/Amylose Inclusion Complexes ». Applied Spectroscopy 67, n^o 8 (août 2013) : 884–91. http://dx.doi.org/10.1366/12-06981.

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Iyengar, Suman, et Michael C. Biewer. « Observation of photochromic γ-cyclodextrin host–guest inclusion complexes ». Chemical Communications, n^o 13 (31 mai 2002) : 1398–99. http://dx.doi.org/10.1039/b204322j.

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Iyengar, Suman, et Michael C. Biewer. « Solid-State Interactions in Photochromic Host−Guest Inclusion Complexes† ». Crystal Growth & ; Design 5, n^o 6 (novembre 2005) : 2043–45. http://dx.doi.org/10.1021/cg050313b.

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Roy, Mahendra Nath, Deepak Ekka, Subhadeep Saha et Milan Chandra Roy. « Host–guest inclusion complexes of α and β-cyclodextrins with α-amino acids ». RSC Adv. 4, n^o 80 (2014) : 42383–90. http://dx.doi.org/10.1039/c4ra07877b.

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The innovative study reveals the formation of 1:1 hosts–guest inclusion complexes for all the titled α-amino acids in the hydrophobic cavity of both α and β-cyclodextrin. The thermodynamic parameters for inclusion were studied depending on size and state of the guest molecules to draw inferences about contributions to the overall binding.

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Nutho, Bodee, Nadtanet Nunthaboot, Peter Wolschann, Nawee Kungwan et Thanyada Rungrotmongkol. « Metadynamics supports molecular dynamics simulation-based binding affinities of eucalyptol and beta-cyclodextrin inclusion complexes ». RSC Advances 7, n^o 80 (2017) : 50899–911. http://dx.doi.org/10.1039/c7ra09387j.

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The development of various molecular dynamics methods enables the detailed investigation of association processes, like host–guest complexes, including their dynamics and, additionally, the release of the guest compound.

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Warttmann, Inge, et Günter Häfelinger. « Ab initio MO Optimizations of Osmiumtetracarbonyldihydride and Metallacyclophanes with two Osmium Atoms and their Molecular Complexes with Different Guests ». Zeitschrift für Naturforschung B 53, n^o 10 (1 octobre 1998) : 1223–35. http://dx.doi.org/10.1515/znb-1998-1020.

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AbstractAb initio Hartree-Fock (HF) and density functional (DFT) optimizations on the test m olecule osmiumtetracarbonyldihydride (13) with various basis sets show that the lanl2mb pseudopotential basis set for osmium leads in the HF approximation to more reliable molecular geometries than the DFT calculations. This HF procedure was used for the optimizations of molecular geometries of three isomeric 4,4,4,4,17,17,17,17-octacarbonyl-4,17-diosma[7.7]ortho-, meta- and paracyclophanes 1 to 3, of which 3 was found to be predestined for formation of various host-guest complexes with possible guests benzene (4), fluorobenzene (5), 1,3,5- trifluorobenzene (6), 1,2,4,5-tetrafluorobenzene (7), hexafluorobenzene (8), fluoroanil (9), tetrafluoroethene (10), tetracyanoethene (11) and aniline (12). Results of optimized hostguest geometries are presented graphically for inclusions and associations of guest 4 to 12 with 3. Calculated lanl2mb interaction energies, after correction for basis set superposition error (BSSE), remain favourable only for inclusion of 5 and associations of 5, 10, 11 and 12. Additionally lanl2dz single point calculations for inclusion, which may not need BSSE correction because of the improved basis set, are favourable for 6 and 12. According to lanl2mb HOMO and LUMO energies, 3 may as well easily donate or accept electrons. This may be an interpretation to the surprising effect, that Mulliken total charges are positive on the electron accepting guest molecules 4 to 11. There are geometrical peculiarities in the optimized host-guest complexes for inclusion and association. Fluorine atoms of 5 to 10 and nitrogen atoms of a cyano group of 11 and the amino group of 12 like to come close to one or two carbonyl groups. Similar distances of 2.70 Å to 3.57 Å between the O atom of the carbonyl group and the F atom or N atom appear in all optimizations of inclusion and association of 5 to 12 except in the case of association of tetrafluoroethene (10).

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Saha, Subhadeep, Tanusree Ray, Saptarshi Basak et Mahendra Nath Roy. « NMR, surface tension and conductivity studies to determine the inclusion mechanism : thermodynamics of host–guest inclusion complexes of natural amino acids in aqueous cyclodextrins ». New Journal of Chemistry 40, n^o 1 (2016) : 651–61. http://dx.doi.org/10.1039/c5nj02179k.

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Assaf, Khaleel I., Husam Abed alfattah, Ala'a F. Eftaiha, Sanaa K. Bardaweel, Mohammad A. Alnajjar, Fatima A. Alsoubani, Abdussalam K. Qaroush, Musa I. El-Barghouthi et Werner M. Nau. « Encapsulation of ionic liquids inside cucurbiturils ». Organic & ; Biomolecular Chemistry 18, n^o 11 (2020) : 2120–28. http://dx.doi.org/10.1039/d0ob00001a.

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Aramoto, Hikaru, Motofumi Osaki, Subaru Konishi, Chiharu Ueda, Yuichiro Kobayashi, Yoshinori Takashima, Akira Harada et Hiroyasu Yamaguchi. « Redox-responsive supramolecular polymeric networks having double-threaded inclusion complexes ». Chemical Science 11, n^o 17 (2020) : 4322–31. http://dx.doi.org/10.1039/c9sc05589d.

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Chen, Ning, et Ya Bin Li. « Study on the Inclusion Behavior of Cucurbit [n] uril with Phenylalanine ». Advanced Materials Research 197-198 (février 2011) : 1153–56. http://dx.doi.org/10.4028/www.scientific.net/amr.197-198.1153.

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The characteristics of host-guest complexes between cucurbit[n]uril (CB [n]) and phenylalanine were investigated by UV-visible absorption spectroscopy in acetate buffer solution at room temperature. It was found that the UV-visible absorption increased steadily with constantly dropping the high concentration of cucurbit[6]uril (CB [6]) and cucurbit[8]uril (CB [8]) in the phenylalanine solution which indicates that there are some interaction betweenCB [n] and phenylalanine.Then CB [6] and phenylalanine at molar ratio of 1:1 to weigh while CB [8] and phenylalanine at molar ratio of 1:2, respectively, are both demonstrated by 1H NMR spectra. 1H NMR spectrum of complexes was obtained, indicating an enthalpic driving force for host-guest complexes. The possible interaction mechanism and inclusion mode were also discussed. This work may extend the application range of CB [n] in supramolecular and pharmaceutical analysis.

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Prabodh, Amrutha, Stephan Sinn, Laura Grimm, Zsombor Miskolczy, Mónika Megyesi, László Biczók, Stefan Bräse et Frank Biedermann. « Teaching indicators to unravel the kinetic features of host–guest inclusion complexes ». Chemical Communications 56, n^o 82 (2020) : 12327–30. http://dx.doi.org/10.1039/d0cc03715j.

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Three new, practically convenient methods are introduced for measuring kinetic parameters of supramolecular host–guest and protein–ligand complexes. Combined with thermodynamic data, this allows for an in-depth of the binding mechanism.

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Pan, Fangfang, Mohadeseh Dashti, Michael R. Reynolds, Kari Rissanen, John F. Trant et Ngong Kodiah Beyeh. « Halogen bonding and host–guest chemistry between N-alkylammonium resorcinarene halides, diiodoperfluorobutane and neutral guests ». Beilstein Journal of Organic Chemistry 15 (18 avril 2019) : 947–54. http://dx.doi.org/10.3762/bjoc.15.91.

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Single crystal X-ray structures of halogen-bonded assemblies formed between host N-hexylammonium resorcinarene bromide (1) or N-cyclohexylammonium resorcinarene chloride (2), and 1,4-diiodooctafluorobutane and accompanying small solvent guests (methanol, acetonitrile and water) are presented. The guests’ inclusion affects the geometry of the cavity of the receptors 1 and 2, while the divalent halogen bond donor 1,4-diiodooctafluorobutane determines the overall nature of the halogen bond assembly. The crystal lattice of 1 contains two structurally different dimeric assemblies A and B, formally resulting in the mixture of a capsular dimer and a dimeric pseudo-capsule. 1H and 19F NMR analyses supports the existence of these halogen-bonded complexes and enhanced guest inclusion in solution.

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Hunt, Lee E., Susan A. Bourne et Mino R. Caira. « Inclusion of Hydroxycinnamic Acids in Methylated Cyclodextrins : Host-Guest Interactions and Effects on Guest Thermal Stability ». Biomolecules 11, n^o 1 (31 décembre 2020) : 45. http://dx.doi.org/10.3390/biom11010045.

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There is ongoing interest in exploiting the antioxidant activity and other medicinal properties of natural monophenolic/polyphenolic compounds, but their generally low aqueous solubility limits their applications. Numerous studies have been undertaken to solubilize such compounds via supramolecular derivatization with co-crystal formation with biocompatible coformer molecules and cyclodextrin (CD) complexation being two successful approaches. In this study, eight new crystalline products obtained by complexation between methylated cyclodextrins and the bioactive phenolic acids (ferulic, hydroferulic, caffeic, and p-coumaric acids) were investigated using thermal analysis (hot stage microscopy, thermogravimetry, differential scanning calorimetry) and X-ray diffraction. All of the complexes crystallized as ternary systems containing the host CD, a phenolic acid guest, and water. On heating each complex, the primary thermal events were dehydration and liberation of the respective phenolic acid component, the mass loss for the latter step enabling determination of the host-guest stoichiometry. Systematic examination of the X-ray crystal structures of the eight complexes enabled their classification according to the extent of inclusion of each guest molecule within the cavity of its respective CD molecule. This revealed three CD inclusion compounds with full guest encapsulation, three with partial guest inclusion, and two that belong to the rare class of ‘non-inclusion’ compounds.

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Cetina, Mario, et Kari Rissanen. « From Self-inclusion and Host-guest Complexes to Channel Structures ». Croatica Chemica Acta 85, n^o 3 (2012) : 319–25. http://dx.doi.org/10.5562/cca2058.

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Saenger, W., et T. Steiner. « Cyclodextrin Inclusion Complexes : Host–Guest Interactions and Hydrogen-Bonding Networks ». Acta Crystallographica Section A Foundations of Crystallography 54, n^o 6 (1 novembre 1998) : 798–805. http://dx.doi.org/10.1107/s0108767398010733.

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Fabbiani, F. P. A., G. Buth, R. Granero García, F. J. Lahoz, C. Paulmann et S. Saouane. « Host–guest interactions in cyclodextrin inclusion complexes at extreme conditions ». Acta Crystallographica Section A Foundations of Crystallography 68, a1 (7 août 2012) : s115. http://dx.doi.org/10.1107/s0108767312097772.

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Wang, Jin, et Xuetong Zhang. « Binary Crystallized Supramolecular Aerogels Derived from Host–Guest Inclusion Complexes ». ACS Nano 9, n^o 11 (2 novembre 2015) : 11389–97. http://dx.doi.org/10.1021/acsnano.5b05281.

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Zhang, Jinyu, Dan Xu, Wenjing Qian, Jingyue Zhu et Feng Yan. « Host–guest inclusion complexes derived heteroatom-doped porous carbon materials ». Carbon 105 (août 2016) : 183–90. http://dx.doi.org/10.1016/j.carbon.2016.04.034.

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Tirapegui, Cristian, Francisco Jara, Juan Guerrero et Marcos Caroli Rezende. « Host–guest interactions in cyclodextrin inclusion complexes with solvatochromic dyes ». Journal of Physical Organic Chemistry 19, n^o 11 (novembre 2006) : 786–92. http://dx.doi.org/10.1002/poc.1080.

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Mosinger, Jiří, Viktor Kliment, Jan Sejbal, Pavel Kubát et Kamil Lang. « Host-guest complexes of anionic porphyrin sensitizers with cyclodextrins ». Journal of Porphyrins and Phthalocyanines 06, n^o 08 (août 2002) : 514–26. http://dx.doi.org/10.1142/s1088424602000646.

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The photodynamic sensitizers zinc(II)- and palladium(II)-5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrins and 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin form 1:1 and/or 1:2 supramolecular complexes with native cyclodextrins (CD) and 2-hydroxypropyl cyclodextrins (hpCD) in aqueous neutral solutions. The formation of these assemblies causes a bathochromic shift of the porphyrin Soret band in the UV-vis spectra and a red shift of the fluorescence emission bands. The binding constants span over three orders of magnitude, from 8.1 × 102 M −1 to 5.4 × 105 M −1 (or 1.1 × 106 M −2) depending on the size of the CD cavity and on the functionalization by adding 2-hydroxypropyl groups. The highest binding constants were obtained for hpβCD and hpγCD. The Nuclear Overhauser spectroscopy signals (ROESY) revealed three binding modes: i) inclusion of the porphyrin 4-sulfonatophenyl or 4-carboxyphenyl groups via the secondary face of βCD and hpβCD with sulfonic or carboxylic groups oriented towards the primary hydroxyl groups. ii) inclusion of the porphyrin groups via the primary face of γCD and hpγCD. iii) non-specific binding of the porphyrin monomers or aggregates on the cyclodextrin exterior. The inclusion host-guest complexation via i) or ii) does not influence the inherent photophysical properties of the monomeric porphyrins such as the quantum yields of fluorescence, the triplet states, and the singlet oxygen formation. Due to the deaggregation effect of cyclodextrins, the inclusion complexes remain efficient supramolecular sensitizers of singlet oxygen even under conditions of extensive aggregation in aqueous solutions.

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Roy, Mahendra Nath, Subhadeep Saha, Siti Barman et Deepak Ekka. « Host–guest inclusion complexes of RNA nucleosides inside aqueous cyclodextrins explored by physicochemical and spectroscopic methods ». RSC Advances 6, n^o 11 (2016) : 8881–91. http://dx.doi.org/10.1039/c5ra24102b.

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Lee, Jae-ung, Sung-Sik Lee, Sungyul Lee et Han Bin Oh. « Noncovalent Complexes of Cyclodextrin with Small Organic Molecules : Applications and Insights into Host–Guest Interactions in the Gas Phase and Condensed Phase ». Molecules 25, n^o 18 (4 septembre 2020) : 4048. http://dx.doi.org/10.3390/molecules25184048.

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Cyclodextrins (CDs) have drawn a lot of attention from the scientific communities as a model system for host–guest chemistry and also due to its variety of applications in the pharmaceutical, cosmetic, food, textile, separation science, and essential oil industries. The formation of the inclusion complexes enables these applications in the condensed phases, which have been confirmed by nuclear magnetic resonance (NMR) spectroscopy, X-ray crystallography, and other methodologies. The advent of soft ionization techniques that can transfer the solution-phase noncovalent complexes to the gas phase has allowed for extensive examination of these complexes and provides valuable insight into the principles governing the formation of gaseous noncovalent complexes. As for the CDs’ host–guest chemistry in the gas phase, there has been a controversial issue as to whether noncovalent complexes are inclusion conformers reflecting the solution-phase structure of the complex or not. In this review, the basic principles governing CD’s host–guest complex formation will be described. Applications and structures of CDs in the condensed phases will also be presented. More importantly, the experimental and theoretical evidence supporting the two opposing views for the CD–guest structures in the gas phase will be intensively reviewed. These include data obtained via mass spectrometry, ion mobility measurements, infrared multiphoton dissociation (IRMPD) spectroscopy, and density functional theory (DFT) calculations.

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Chen, Shunwei, Zhe Han, Dongju Zhang et Jinhua Zhan. « Theoretical study of the inclusion complexation of TCDD with cucurbit[n]urils ». RSC Adv. 4, n^o 94 (2014) : 52415–22. http://dx.doi.org/10.1039/c4ra06011c.

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Stasyuk, Anton J., Olga A. Stasyuk, Miquel Solà et Alexander A. Voityuk. « Photoinduced electron transfer in nanotube⊃C70 inclusion complexes : phenine vs. nanographene nanotubes ». Chemical Communications 56, n^o 83 (2020) : 12624–27. http://dx.doi.org/10.1039/d0cc04261g.

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The six-atom vacancy defects regularly located throughout the nanotubes change the electronic properties of their inclusion complexes with fullerene and prevent the photoinduced electron transfer between host and guest molecules.

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Litim, Abdelkarim, Youghourta Belhocine, Tahar Benlecheb, Monira Galal Ghoniem, Zoubir Kabouche, Fatima Adam Mohamed Ali, Babiker Yagoub Abdulkhair, Mahamadou Seydou et Seyfeddine Rahali. « DFT-D4 Insight into the Inclusion of Amphetamine and Methamphetamine in Cucurbit[7]uril : Energetic, Structural and Biosensing Properties ». Molecules 26, n^o 24 (10 décembre 2021) : 7479. http://dx.doi.org/10.3390/molecules26247479.

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The host–guest interactions of cucurbit[7]uril (CB[7]) as host and amphetamine (AMP), methamphetamine (MET) and their enantiomeric forms (S-form and R-form) as guests were computationally investigated using density functional theory calculations with the recent D4 atomic-charge dependent dispersion corrections. The analysis of energetic, structural and electronic properties with the aid of frontier molecular orbital analysis, charge decomposition analysis (CDA), extended charge decomposition analysis (ECDA) and independent gradient model (IGM) approach allowed to characterize the host–guest interactions in the studied systems. Energetic results indicate the formation of stable non-covalent complexes where R-AMP@CB[7] and S-AMP@CB[7] are more stable thermodynamically than R-MET@CB[7] and S-MET@CB[7] in gas phase while the reverse is true in water solvent. Based on structural analysis, a recognition mechanism is proposed, which suggests that the synergistic effect of van der Waals forces, ion–dipole interactions, intermolecular charge transfer interactions and intermolecular hydrogen bonding is responsible for the stabilization of the complexes. The geometries of the complexes obtained theoretically are in good agreement with the X-ray experimental structures and indicate that the phenyl ring of amphetamine and methamphetamine is deeply buried into the cavity of CB[7] through hydrophobic interactions while the ammonium group remains outside the cavity to establish hydrogen bonds with the portal oxygen atoms of CB[7].

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Cheng, Si-Yuan, Yun-Xia Qu, Zhu Tao, Kai-Zhi Zhou, Lian-Tong Wei, Cong Wang, Wei-Wei Zhao, Dao-Fa Jiang et Pei-Hua Ma. « The Host–Guest Properties Observed Between the Viologens and Cyclopentanocucurbit[6]uril ». Australian Journal of Chemistry 73, n^o 7 (2020) : 601. http://dx.doi.org/10.1071/ch19400.

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The interactions between cyclopentanocucurbit[6]uril (abbreviated as CyP6Q[6]) and a series of dialkyl-4,4′-bipyridinium and diaryl-4,4′-bipyridinium dicationic guest molecules, where the alkyl group is CH3(CH2)n with n=0–6 (expressed as G1 to G7) and the aryl group is phenylene (G8) and xylene (G9), have been investigated in aqueous solution using 1H NMR spectroscopy, isothermal titration calorimetry (ITC), and electronic absorption spectroscopy. Our results show that G1 and G2 form 1:1 host–guest inclusion complexes with CyP6Q[6], in which the bipyridinium core is partially embedded in the cavity of CyP6Q[6]. G3–G9 form 2:1 dumbbell-type host–guest inclusion complexes, in which the substituents are encapsulated by CyP6Q[6]. At the same time, CyP6Q[6] was compared with several other cucurbit[n]urils (Q[n]s) and their derivatives, such as Q[6], Q[7], and TMeQ[6], which have been reported to interact with this type of guest molecule. In its binding mode, CyP6Q[6] shows many interesting and different properties, and this difference was mainly reflected with G1 and G2.

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Dračínský, Martin, Carina Santos Hurtado, Eric Masson et Jiří Kaleta. « Stuffed pumpkins : mechanochemical synthesis of host–guest complexes with cucurbit[7]uril ». Chemical Communications 57, n^o 17 (2021) : 2132–35. http://dx.doi.org/10.1039/d1cc00240f.

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Herbstein, F. H. « Conformational Isomerism of the Host as a Factor in Molecular Recognition in Host–Guest Inclusion Complexes : Example of Tris(5-acetyl-3-thienyl)methane ». Acta Crystallographica Section B Structural Science 53, n^o 1 (1 février 1997) : 168–75. http://dx.doi.org/10.1107/s0108768196010907.

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The tripod molecule tris(5-acetyl-3-thienyl)methane (TATM) is a flexile molecule, i.e. one that can occur in many conformationally isomeric states (conformers), which forms host–guest inclusion complexes with a large variety of guests (solvents). Some 40-odd different types of guest have been reported to form inclusion complexes. Five different types of crystal structure (all racemic), with nine different guests, have been reported in the literature and structural information is available for 17 crystallographically independent TATM molecules; most of the guests are disordered. Our analysis of this (substantial but, nevertheless, incomplete) database shows that each group of crystallographically isomorphous structures contains a particular TATM conformer with characteristic torsion angles about the bonds between methane carbon and the three thienyl rings (τ1, τ2 and τ3); the range of torsion angles in a particular structural group does not exceed 10°. Conformers are in addition distinguished via the stereochemistry of the acetyl group; there are approximately equal numbers of examples with carbonyl oxygen syn or anti to ring sulfur, intermediate conformations not being found. So far three different types of conformer have been encountered for the TATM molecule considered as an entity. A necessary condition for the occurrence of a particular conformer type is that the torsion angles τ1, τ2 and τ3 are such that ring H atoms should not approach more closely than (say) 2.4 Å, but this is not sufficient as considerably larger distances are found in some conformer types. Crystallization of the inclusion complex from a particular solvent can be envisaged to occur as follows. The TATM solution will contain a Boltzmann distribution of host conformers, the distribution depending on temperature but not on the nature of the solvent. Under suitable temperature and solubility conditions, the solvent will crystallize together with the appropriate conformer to form the inclusion complex-nuclei formed at this recognition stage, then grow into crystallites of the inclusion complex. The perturbed Boltzmann distribution (depleted in appropriate conformer) will continuously revert to its equilibrium form by conversion of the non-appropriate into the appropriate conformer as the crystallization proceeds.

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Kawase, Takeshi, et Masaji Oda. « Complexation of carbon nanorings with fullerenes ». Pure and Applied Chemistry 78, n^o 4 (1 janvier 2006) : 831–39. http://dx.doi.org/10.1351/pac200678040831.

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To explore the supramolecular properties of the hollow space of carbon nanotubes, the belt-shaped conjugated systems with sizable and deep cavities are intriguing molecules. Recently, we found that the "carbon nanorings", cyclic [6]paraphenyleneacetylene ([6]CPPA), and the related compounds involving two naphthylene rings, form stable inclusion complexes with fullerenes in solution as well as in the solid state. The stability of these complexes correlates well with the van der Waals (VDW) contact between the host and guest. Thus, carbon nanorings having a deep cavity should form considerably stable complexes with fullerenes. In this context, we have designed a new carbon nanoring, cyclic [6](1,4)naphthyleneacetylene. The host forms considerably stable inclusion complexes with fullerenes and can act as the best fluorescence sensor for fullerenes among all the known hosts. The NMR spectra reveal the formation of two major conformational isomers, in which five or six naphthylene rings surround a guest molecule to gain wide contact area. The high affinity between C60 and naphthylene rings similar to an ion-dipolar interaction plays an important role in the novel guest-induced conformation fixation.

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Ferino-Pérez, Anthuan, Juan José Gamboa-Carballo, Ronald Ranguin, Joëlle Levalois-Grützmacher, Yves Bercion, Sarra Gaspard, Ramón Alain Miranda-Quintana, Melvin Arias et Ulises J. Jáuregui-Haza. « Evaluation of the molecular inclusion process of β-hexachlorocyclohexane in cyclodextrins ». RSC Advances 9, n^o 47 (2019) : 27484–99. http://dx.doi.org/10.1039/c9ra04431k.

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The present work aimed to study the guest–host complexes of β-hexachlorocyclohexane (β-HCH), a pesticide with high environmental stability that can cause severe health problems, with the most common cyclodextrins (α-, β-, and γ-CDs).

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Ono, Toshikazu, et Yoshio Hisaeda. « Vapochromism of Organic Crystals Based on Macrocyclic Compounds and Inclusion Complexes ». Symmetry 12, n^o 11 (19 novembre 2020) : 1903. http://dx.doi.org/10.3390/sym12111903.

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Vapochromic materials, which change color and luminescence when exposed to specific vapors and gases, have attracted considerable attention in recent years owing to their potential applications in a wide range of fields such as chemical sensors and environmental monitors. Although the mechanism of vapochromism is still unclear, several studies have elucidated it from the viewpoint of crystal engineering. In this mini-review, we investigate recent advances in the vapochromism of organic crystals. Among them, macrocyclic molecules and inclusion complexes, which have apparent host–guest interactions with analyte molecules (specific vapors and gases), are described. When the host compound is properly designed, its cavity size and symmetry change in response to guest molecules, influencing the optical properties by changing the molecular inclusion and recognition abilities. This information highlights the importance of structure–property relationships resulting from the molecular recognition at the solid–vapor interface.

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Magalhães, Clara I. R., Ana C. Gomes, André D. Lopes, Isabel S. Gonçalves, Martyn Pillinger, Eunyoung Jin, Ikjin Kim et al. « Ferrocene and ferrocenium inclusion compounds with cucurbiturils : a study of metal atom dynamics probed by Mössbauer spectroscopy ». Physical Chemistry Chemical Physics 19, n^o 32 (2017) : 21548–55. http://dx.doi.org/10.1039/c7cp04416j.

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Triamchaisri, Nat, Pisanu Toochinda et Luckhana Lawtrakul. « Structural Investigation of Beta-Cyclodextrin Complexes with Cannabidiol and Delta-9-Tetrahydrocannabinol in 1:1 and 2:1 Host-Guest Stoichiometry : Molecular Docking and Density Functional Calculations ». International Journal of Molecular Sciences 24, n^o 2 (12 janvier 2023) : 1525. http://dx.doi.org/10.3390/ijms24021525.

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The complexation of β-cyclodextrin (β-CD) with cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) was investigated using molecular docking and M062X/6-31G(d,p) calculations. The calculations suggested two possible complex formations of 1:1 and 2:1 host-guest molecular ratio of β-CD with CBD and THC. The preferred orientation of all complexes in this study exhibited the hydrogen bonding between hydroxy-substituted benzene ring of CBD and THC with the β-CD’s secondary hydroxy groups at the wide rim. The calculated complexation energies indicate that formation of the 2:1 complexes (−83.53 to −135.36 kcal/mol) was more energetically favorable and chemically stable than the 1:1 complexes (−30.00 to −34.92 kcal/mol). However, the deformation energies of the host and the guest components in the 2:1 complexes (37.47–96.91 kcal/mol) are much higher than those in the 1:1 complexes (3.49–8.69 kcal/mol), which means the formation processes of the 2:1 complexes are more difficult due to the rigidity of the dimeric β-CDs. Therefore, the inclusion complexes of β-CD with CBD and THC are more likely to be in 1:1 host-guest ratio than in 2:1 molecular ratio. The results of this study supported the experimental results that the complexation constant of 1:1 β-CD/CBD (Ks = 300 M−1) is greater than that of 2:1 β-CDs/CBD (Kss = 0.833 M−1). Altogether, this study introduced the fitting parameters that could indicate the stability of the molecular fits in complex formation of each stoichiometry host-guest ratio, which are important for the assessment of the inclusion mechanisms as well as the relationships of reactants and products in chemical reactions.

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Caira, Mino, Susan Bourne et Buntubonke Mzondo. « Cyclodextrin inclusion complexes of the antioxidant α-lipoic acid ». Acta Crystallographica Section A Foundations and Advances 70, a1 (5 août 2014) : C992. http://dx.doi.org/10.1107/s205327331409007x.

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Owing to its potent antioxidant activity,α-lipoic acid (1,2-dithiolane-3-pentanoic acid) is widely used as a supplement and is recommended for treating a number of conditions including chronic liver disease and diabetes. The poor aqueous solubility of the acid (~0.003 M at 250C) has prompted studies of its interaction with cyclodextrins (CDs) as a possible route to improving its solubility. However, relatively few studies have focused on the isolation of solid CD inclusion complexes of the antioxidant, and in most cases the racemic form of the acid was employed. In the comprehensive study reported here, the bioactive (R)-(+)-enantiomeric form of the molecule was used exclusively, resulting in the isolation and structural characterization of its inclusion complexes with each of the native host CDs (α-, β- and γ-CD) as well as permethylated α-CD (TRIMEA), permethylated β-CD (TRIMEB) and 2,6-dimethylated-β-CD (DIMEB). The α-CD complex crystallizes in the trigonal system, space group R32, with three independent CD molecules in the asymmetric unit and is not isostructural with any known CD complex while the β-CD complex crystallizes in the monoclinic system (C2). With the host γ-CD, an orthorhombic (pseudo-tetragonal) inclusion complex was identified, an unusual result as γ-CD complexes generally crystallize in the tetragonal space group P4212. The complexes with TRIMEA and TRIMEB crystallize in the orthorhombic system (P212121), the modes of inclusion of the (R)-(+)-α-lipoic acid molecule in the respective hosts being reversed: the guest molecule is fully encapsulated by the former host with the dithiolane ring located at the secondary rim, while in the latter host, the dithiolane ring rests on the concave surface of the host cavity at the primary side. A significant level of guest disorder was detected in the inclusion complex with DIMEB (P21). Thermal and phase-solubility analyses complemented the X-ray structural studies.

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