Positions of amino groups on ammonium salts tunes the conformations of crown ethers: crystal structures, Hirshfeld surfaces and spectroscopic studies

Luo, Yang‐Hui; Wu, Dong-En; Wei, Song; Ge, Shu-Wang; Sun, Bai-Wang

doi:10.1039/c4ce00150h

Cited by 18 publications

(10 citation statements)

References 67 publications

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“…It may be noted that the so-called strong synthons, such as carboxylic acid dimer, amide dimer, etc., have interaction energies around 60–70 kJ·mol –1 . A well-known supramolecular recognition unit involving 18-crown-6 and organic moieties is the ammonium cation:18-crown-6 motif. − The interaction energies for these motifs have been found to be around 200–270 kJ·mol –1 . While these very high interaction strengths are due to the cationic binding, the corresponding neutral amine:18-crown-6 binding strengths have been found to be in the range 45–70 kJ·mol –1 .…”

Section: Resultsmentioning

confidence: 99%

Supramolecular Recognition and Energy Frameworks in Host–Guest Complexes of 18-Crown-6 and Sulfonamides

Shi

Thomas

Koutsantonis

et al. 2015

Crystal Growth & Design

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Crystalline molecular complexes of 18-crown-6 with three sulfonamide analogues (methane, benzene, and toluene sulfonamides) have been synthesized and characterized. Among these, the 18-crown-6:benzenesulfonamide complex exhibits three crystal forms, including a polymorphic pair. Interaction energy calculations show that the host−guest binding energies in these complexes are very high (∼92−104 kJ•mol −1 ). Energy framework analysis identifies the hierarchy of intermolecular interactions and their topology; a trimeric motif formed by two guest molecules and a crown host is found to be a salient structural feature in these complexes. This study establishes the "sulfonamide-crown motif" as a very robust and predictable supramolecular recognition unit.

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Section: Resultsmentioning

confidence: 99%

Supramolecular Recognition and Energy Frameworks in Host–Guest Complexes of 18-Crown-6 and Sulfonamides

Shi

Thomas

Koutsantonis

et al. 2015

Crystal Growth & Design

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“…47 In our previous work, we have investigated in detail the influence of substituents on the secondary interactions in crown ether-ammonium salt. 48 Herein, we report the influence of a magnetic field with different strengths (0.0, 0.5, 1.0, and 1.5 T) on the cocrystallization of 18-crown-6 (18-C-6) with 4,5dicyanoimidazole (4,5-dci), which results in different cocrystals 1-0.0T, 1-0.5T, 1-1.0T, and 1-1.5T (Scheme 1), respectively. Structural analysis revealed that the presence of an external magnetic field can result in elongating of the distance within cocrystals upon elongating.…”

Section: ■ Introductionmentioning

confidence: 99%

“…The host–guest interaction between crown ethers and guest molecules is an important secondary interaction, which can be applied to mimic natural systems or construct new materials . In our previous work, we have investigated in detail the influence of substituents on the secondary interactions in crown ether-ammonium salt . Herein, we report the influence of a magnetic field with different strengths (0.0, 0.5, 1.0, and 1.5 T) on the cocrystallization of 18-crown-6 (18-C-6) with 4,5-dicyanoimidazole (4,5-dci), which results in different cocrystals 1 -0.0T, 1 -0.5T, 1 -1.0T, and 1 -1.5T (Scheme ), respectively.…”

Section: Introductionmentioning

confidence: 99%

Reversibly Stretching Cocrystals by the Application of a Magnetic Field

Luo

Wang

Chen

et al. 2017

Crystal Growth & Design

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Careful control of the noncovalent supramolecular interactions for the preparation of organic cocrystal materials with tailored properties is a challenging task. Herein, we report the reversible stretching of the distances between coformers (18-Crown-6/4,5-dicyanoimidazole (cocrystal 1) and (18-Crown-6/1,2,4-triazole (cocrystal 2) in the solution state, by the application of an external magnetic field with various strengths (0.0, 0.5, 1.0, and 1.5 T). As a consequence, the physical/chemical properties of the stretched cocrystals 1-0.5T, 1-1.0T, and 2-0.5T have been remarkably altered to close to the individual coformers, and finally, cocrystals 1 and 2 can be broken under 1.5 and 1.0 T, respectively. Thus, the stretching mechanism of a magnetic field can be proposed. This stretching effect, however, may therefore be of great interest in functional organic cocrystal materials that are tuned by noncovalent supramolecular interactions.

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“…Many efforts have been focused on the investigation of the reduction in the k of PIs . 18‐Crown‐6 (CE6) with annular pore structure had been employed to construct 18‐crown‐6‐polyimide complex (CE6‐PI) . The k of PI could be effectively reduced to 2.99 due to the shielding effect of low‐polarity CE6 on its strong polar imide groups .…”

Section: Introductionmentioning

confidence: 99%

Dielectric Constant, Thermal and Mechanical Properties of Ladder‐Like Polypropylsilsesquioxane/Crown Ether‐Polyimide Nanocomposites

Shi

Liu

et al. 2019

Macro Chemistry & Physics

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Ladder‐like polypropylsilsesquioxane (LPSQ) with inorganic SiOSi double‐stranded skeleton in situ growth is incorporated into 18‐crown‐6‐polyimide (CE6‐PI) chains by coupling effect of aminopropyltrimethoxysilane to build ladder‐like polypropylsilsesquioxane/18‐crown‐6‐polyimide (LPSQ/CE6‐PI) nanocomposites. The dielectric constant is evidently decreased, and the strength, toughness, and thermal stability of CE6‐PI are greatly improved. A low dielectric constant of 2.71 as well as high tensile strength of 133.7 MPa and toughness of 29.7 MJ m−3 are achieved for the LPSQ/CE6‐PI nanocomposite with 23.2 wt% LPSQ. Meanwhile, its glass transition temperature and 5% weight loss temperature exhibit an increase of 23.1 °C and 68.8 °C, respectively, based on CE6‐PI. Positron annihilation lifetime spectroscopy, X‐ray diffraction patterns, dynamic mechanical analysis, and scanning electron microscope images are applied to investigate the effect of LPSQ on the structure of LPSQ/CE6‐PI nanocomposites.

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Positions of amino groups on ammonium salts tunes the conformations of crown ethers: crystal structures, Hirshfeld surfaces and spectroscopic studies

Abstract: The position of the amino group on the ammonium salt plays a key role in the supramolecular structure and conformation of the crown ether.

Cited by 18 publications

References 67 publications

Supramolecular Recognition and Energy Frameworks in Host–Guest Complexes of 18-Crown-6 and Sulfonamides

Supramolecular Recognition and Energy Frameworks in Host–Guest Complexes of 18-Crown-6 and Sulfonamides

Reversibly Stretching Cocrystals by the Application of a Magnetic Field

Dielectric Constant, Thermal and Mechanical Properties of Ladder‐Like Polypropylsilsesquioxane/Crown Ether‐Polyimide Nanocomposites

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