6 research outputs found

    Β«ΠœΠ°Π»ΠΎΠ±ΡŽΠ΄ΠΆΠ΅Ρ‚Π½ΠΈΠΉΒ» ΠΌΠ°Ρ€ΠΊΠ΅Ρ‚ΠΈΠ½Π³

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    Π’ ΡƒΠΌΠΎΠ²Π°Ρ… ΡΡŒΠΎΠ³ΠΎΠ΄Π½Ρ–ΡˆΠ½ΡŒΠΎΡ— Π΅ΠΊΠΎΠ½ΠΎΠΌΡ–Ρ‡Π½ΠΎΡ— ΠΊΡ€ΠΈΠ·ΠΈ, яка Π·Π°Ρ‡Π΅ΠΏΠΈΠ»Π° всі вітчизняні підприємства, Ρ‚Π° постійного зниТСння ΡƒΠΊΡ€Π°Ρ—Π½ΡΡŒΠΊΠΎΡ— Π½Π°Ρ†Ρ–ΠΎΠ½Π°Π»ΡŒΠ½ΠΎΡ— Π²Π°Π»ΡŽΡ‚ΠΈ Π°ΠΊΡ‚ΡƒΠ°Π»ΡŒΠ½ΠΈΠΌΠΈ ΡΡ‚Π°ΡŽΡ‚ΡŒ питання ΠΏΠΎΡˆΡƒΠΊΡƒ способів Π΅ΠΊΠΎΠ½ΠΎΠΌΡ–Ρ— ΠΊΠΎΡˆΡ‚Ρ–Π². Π’ΠΈΡ€Ρ–ΡˆΠ΅Π½Π½ΡΠΌ Ρ‚Π°ΠΊΠΈΡ… ΠΏΡ€ΠΎΠ±Π»Π΅ΠΌ ΠΌΠΎΠΆΠ΅ стати Β«ΠΌΠ°Π»ΠΎ Π±ΡŽΠ΄ΠΆΠ΅Ρ‚Π½ΠΈΠΉΒ» ΠΌΠ°Ρ€ΠΊΠ΅Ρ‚ΠΈΠ½Π³, який Π΄ΠΎΠΏΠΎΠΌΠΎΠΆΠ΅ розвиватися підприємству Π· використанням ΠΌΡ–Π½Ρ–ΠΌΠ°Π»ΡŒΠ½ΠΎΡ— ΠΊΡ–Π»ΡŒΠΊΠΎΡΡ‚Ρ– рСсурсів. Β«ΠœΠ°Π»ΠΎΠ±ΡŽΠ΄ΠΆΠ΅Ρ‚Π½ΠΈΠΉΒ» ΠΌΠ°Ρ€ΠΊΠ΅Ρ‚ΠΈΠ½Π³ – Ρ†Π΅ ΠΌΠ°Ρ€ΠΊΠ΅Ρ‚ΠΈΠ½Π³ΠΎΠ²Ρ– інструмСнти залучСння ΠΉ утримання ΠΊΠ»Ρ–Ρ”Π½Ρ‚Ρ–Π², які ΠΏΡ€ΠΈΠΏΡƒΡΠΊΠ°ΡŽΡ‚ΡŒ ΠΌΡ–Π½Ρ–ΠΌΠ°Π»ΡŒΠ½Ρ– Π²ΠΈΡ‚Ρ€Π°Ρ‚ΠΈ, Π° Ρ–Π½ΠΎΠ΄Ρ– ΠΌΠΎΠΆΠ½Π° Π²Π·Π°Π³Π°Π»Ρ– обійтися Π±Π΅Π· Π±ΡŽΠ΄ΠΆΠ΅Ρ‚Ρƒ

    Acid- and Base-Stable Porous Organic Cages: Shape Persistence and pH Stability via Post-synthetic β€œTying” of a Flexible Amine Cage

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    Imine cage molecules can be reduced to amines to improve their chemical stability, but this introduces molecular flexibility. Hence, amine cages tend not to exhibit permanent solid-state porosity. We report a synthetic strategy to achieve shape persistence in amine cages by tying the cage vertices with carbonyls such as formaldehyde. Shape persistence is predicted by conformer stability calculations, providing a design basis for the strategy. The tied cages show enhanced porosity and unprecedented chemical stability toward acidic and basic conditions (pH 1.7–12.3), where many other porous crystalline solids would fail

    On Crystal versus Fiber Formation in Dipeptide Hydrogelator Systems

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    Naphthalene dipeptides have been shown to be useful low-molecular-weight gelators. Here we have used a library to explore the relationship between the dipeptide sequence and the hydrogelation efficiency. A number of the naphthalene dipeptides are crystallizable from water, enabling us to investigate the comparison between the gel/fiber phase and the crystal phase. We succeeded in crystallizing one example directly from the gel phase. Using X-ray crystallography, molecular modeling, and X-ray fiber diffraction, we show that the molecular packing of this crystal structure differs from the structure of the gel/fiber phase. Although the crystal structures may provide important insights into stabilizing interactions, our analysis indicates a rearrangement of structural packing within the fibers. These observations are consistent with the fibrillar interactions and interatomic separations promoting 1D assembly whereas in the crystals the peptides are aligned along multiple axes, allowing 3D growth. This observation has an impact on the use of crystal structures to determine supramolecular synthons for gelators

    On Crystal versus Fiber Formation in Dipeptide Hydrogelator Systems

    No full text
    Naphthalene dipeptides have been shown to be useful low-molecular-weight gelators. Here we have used a library to explore the relationship between the dipeptide sequence and the hydrogelation efficiency. A number of the naphthalene dipeptides are crystallizable from water, enabling us to investigate the comparison between the gel/fiber phase and the crystal phase. We succeeded in crystallizing one example directly from the gel phase. Using X-ray crystallography, molecular modeling, and X-ray fiber diffraction, we show that the molecular packing of this crystal structure differs from the structure of the gel/fiber phase. Although the crystal structures may provide important insights into stabilizing interactions, our analysis indicates a rearrangement of structural packing within the fibers. These observations are consistent with the fibrillar interactions and interatomic separations promoting 1D assembly whereas in the crystals the peptides are aligned along multiple axes, allowing 3D growth. This observation has an impact on the use of crystal structures to determine supramolecular synthons for gelators

    On Crystal versus Fiber Formation in Dipeptide Hydrogelator Systems

    No full text
    Naphthalene dipeptides have been shown to be useful low-molecular-weight gelators. Here we have used a library to explore the relationship between the dipeptide sequence and the hydrogelation efficiency. A number of the naphthalene dipeptides are crystallizable from water, enabling us to investigate the comparison between the gel/fiber phase and the crystal phase. We succeeded in crystallizing one example directly from the gel phase. Using X-ray crystallography, molecular modeling, and X-ray fiber diffraction, we show that the molecular packing of this crystal structure differs from the structure of the gel/fiber phase. Although the crystal structures may provide important insights into stabilizing interactions, our analysis indicates a rearrangement of structural packing within the fibers. These observations are consistent with the fibrillar interactions and interatomic separations promoting 1D assembly whereas in the crystals the peptides are aligned along multiple axes, allowing 3D growth. This observation has an impact on the use of crystal structures to determine supramolecular synthons for gelators

    On Crystal versus Fiber Formation in Dipeptide Hydrogelator Systems

    No full text
    Naphthalene dipeptides have been shown to be useful low-molecular-weight gelators. Here we have used a library to explore the relationship between the dipeptide sequence and the hydrogelation efficiency. A number of the naphthalene dipeptides are crystallizable from water, enabling us to investigate the comparison between the gel/fiber phase and the crystal phase. We succeeded in crystallizing one example directly from the gel phase. Using X-ray crystallography, molecular modeling, and X-ray fiber diffraction, we show that the molecular packing of this crystal structure differs from the structure of the gel/fiber phase. Although the crystal structures may provide important insights into stabilizing interactions, our analysis indicates a rearrangement of structural packing within the fibers. These observations are consistent with the fibrillar interactions and interatomic separations promoting 1D assembly whereas in the crystals the peptides are aligned along multiple axes, allowing 3D growth. This observation has an impact on the use of crystal structures to determine supramolecular synthons for gelators
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