Structure-Property Relationships to Direct the Dynamic Properties of Acylsemicarbazide-Based Materials DOI Creative Commons

Stefan J. D. Maessen,

Siebe Lekanne Deprez, Pascal Vermeeren

et al.

Polymer Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 4, 2024

Secondary interactions, such as hydrogen bonding or phase separation, can enhance the stability of dynamic covalent materials without compromising on desired properties. Here, we investigate combination multiple secondary interactions in based acylsemicarbazides (ASCs), with aim achieving tunable material The effects different ASC substituents and capabilities were investigated a small molecule study using combined experimental theoretical approach, revealed presence cooperative hydrogen-bonding 2 directions one derivatives. motifs subsequently incorporated into polymeric materials. Combining capable strong, polydimethylsiloxane backbone introduces structure-dependent, ordered nanophase separation thermo-mechanical properties reveal strong dependance structure exact nature bond. behavior bulk shows that bond exchange depends dissociation rate obtained from model compounds, well strength these Differences structures also cause differences creep resistance Interestingly, hydrogen-bonded clusters show highest resistance. Our results demonstrate tuning both by molecular design is important for controlling their thermal

Language: Английский

Regiodivergent Alkylation of Pyridines: Alkyllithium Clusters Direct Chemical Reactivity DOI
Woohyun Jo, Chattawat Thangsrikeattigun,

Changsu Ryu

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 26, 2025

Regiodivergent C-C bond-forming reactions are a powerful tool for constructing diverse molecular architectures from common precursors. While transition metal catalysis has dominated regioselective transformations, achieving similar precision with transition-metal-free methods remains an unmet challenge, particularly when using identical starting materials. In this work, we report transition-metal-free, regiodivergent direct alkylation of electronically unbiased pyridines 1,1-diborylalkanes as the sole alkylating agent. The key to controlling regioselectivity lies in choice alkyllithium activator 1,1-diborylalkanes: methyllithium directs predominantly C4 position, while sec-butyllithium promotes C2-alkylation. Mechanistic studies reveal that structural dynamics clusters dictate regioselectivity, tetrameric favoring C4-alkylation and dimeric preferring This method demonstrates broad substrate scope, enables late-stage functionalization complex molecules, allows sequential installation two distinct alkyl groups onto pyridine scaffold. Our approach provides versatile site-selective functionalization, offering new possibilities synthesizing alkylated pharmaceutical materials research.

Language: Английский

Citations

1
“Hydridic Hydrogen-Bond Donors” Are Not Hydrogen-Bond Donors DOI Creative Commons
Lucas de Azevedo Santos, Pascal Vermeeren, F. Matthias Bickelhaupt

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(37), P. 25701 - 25709

Published: Sept. 3, 2024

Herein, we dismiss a recent proposal by Civiš, Hobza, and co-workers to modify the IUPAC definition of hydrogen bonds in order expand scope from protonic Y-H

Language: Английский

Citations

5
Multiple Bonding in AeN‐ (Ae = Ca, Sr, Ba) DOI Creative Commons

Li‐Juan Cui,

Yu‐Qian Liu,

Menghui Wang

et al.

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(34)

Published: April 16, 2024

Quantum chemical calculations using ab initio methods at the MRCI+Q(8,9)/def2-QZVPPD and CCSD(T)/def2-QZVPPD levels as well density functional theory are reported for diatomic molecules AeN

Language: Английский

Citations

4
2.5-dimensional Voronoi numerical simulation method for migration of direct roof in a longwall face DOI Creative Commons
Bin Yu, Yong Li, Yang Tai

et al.

Journal of Rock Mechanics and Geotechnical Engineering, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Language: Английский

Citations

0
Tetrahedral Nitrogen Atoms Arrangement in A‐Site Cations: A New Approach for Regulating Sensitivity and Energy of Perovskite Energetic Materials DOI Creative Commons
Shiyong Chen, Yuan Gao,

Dong Cheng

et al.

Advanced Science, Journal Year: 2025, Volume and Issue: unknown

Published: March 24, 2025

Perovskite energetic materials (PEMs) are emerging combinations of oxidants and reductives, which promising in explosives owing to the advantages high energy, simple synthesis low cost. However, friction sensitivity currently reported PEMs is so that it limits further application PEMs. In this work, a tetrahedral nitrogen-atom-arrangement structure, urotropine, introduced as A-site cation PEMs, then four urotropine-based ([C6H14N4][M(ClO4)3], named TAPs) successfully constructed experimentally for first time. The crystal reaction progress, thermal decomposition, sensitivity, detonation performance TAPs characterized. results indicate that, different from existing cubic structure experiences compression along c-axis, despite c-axis length being twice or b-axes. As expected, remarkably reduced significantly improved. Moreover, hardness cations proposed key factor affecting impact while C─H···O hydrogen bonds play an important role regulating sensitivity. emergence provides design concept high-energy insensitive unique perspective understanding mechanical materials.

Language: Английский

Citations

0
Molecular dynamics, docking and quantum calculations reveal conformational changes influenced by CYP271A amino acid mutations related to cerebrotendinous xanthomatosis DOI Creative Commons
Yudibeth Sixto‐López, Humberto L. Mendoza‐Figueroa, Bruno Landeros‐Rivera

et al.

Scientific Reports, Journal Year: 2025, Volume and Issue: 15(1)

Published: March 25, 2025

Cerebrotendinous xanthomatosis (CTX) is an autosomal recessive lipid disorder caused by a deficiency in CYP27A1, the first enzyme bile acid biosynthesis pathway. CYP27A1 catalyzes 7α-hydroxylation of cholesterol, playing important role cholesterol homeostasis. CTX leads to progressive neurological dysfunction, including cognitive impairment, epilepsy, peripheral neuropathy, and movement disorders. Missense mutations disrupt its activity, particularly at heme binding region adrenodoxin-binding site. This study examined structural effects seven-point using molecular dynamic (MD) simulations. Both mutant wild-type (WT) proteins were modeled observe their behavior. Additionally, combining MD simulations, docking, quantum calculations was studied WT proteins. Results indicated that altered mode, preventing it from adopting correct position catalytic The substrate access channel mutants became wider, shallower, or closed. interaction between isopropyl group found be crucial for hydroxylation capacity as this only present cholesterol-WT complex.

Language: Английский

Citations

0
The Amsterdam Modeling Suite DOI Creative Commons
Evert Jan Baerends, Néstor F. Aguirre, N. Austin

et al.

The Journal of Chemical Physics, Journal Year: 2025, Volume and Issue: 162(16)

Published: April 22, 2025

In this paper, we present the Amsterdam Modeling Suite (AMS), a comprehensive software platform designed to support advanced molecular and materials simulations across wide range of chemical physical systems. AMS integrates cutting-edge quantum methods, including Density Functional Theory (DFT) time-dependent DFT, with mechanics, fluid thermodynamics, machine learning techniques, more, enable multi-scale modeling complex Its design philosophy allows for seamless coupling between components, facilitating that from small molecules biomolecular solid-state systems, making it versatile tool tackling interdisciplinary challenges, both in industry academia. The suite also emphasizes user accessibility, an intuitive graphical interface, extensive scripting capabilities, compatibility high-performance computing environments.

Language: Английский

Citations

0
Chemical Bonding DOI
Sudip Pan, Gernot Frenking

Published: May 17, 2024

This chapter discusses fundamental aspects of chemical bonding in molecules, highlighting the difference between physical mechanism bond formation and models. The historical development most important models is critically discussed, current understanding nature presented. crucial importance orbital symmetry for structure reactivity molecules emphasized. Further topics concern length strength a bond, electron-sharing A–B dative A→B as well polar bonds. process original fragments A B, which takes into account deformation electronic structures, description finally formed, often confused leads to controversy, few selected model compounds are analyzed using modern methods analysis demonstrate advances sophisticated that have been made. They illustrate differences bonds main group atoms first octal row periodic table heavier homologs, transition metals (TMs).

Language: Английский

Citations

3
Multiple hydrogen-bonded dimers: are only the frontier atoms relevant? DOI Creative Commons
Celine Nieuwland,

David Almacellas,

Mac M. Veldhuizen

et al.

Physical Chemistry Chemical Physics, Journal Year: 2023, Volume and Issue: 26(15), P. 11306 - 11310

Published: Nov. 30, 2023

Non-frontier atom exchanges in hydrogen-bonded aromatic dimers can induce significant interaction energy changes (up to 6.5 kcal mol

Language: Английский

Citations

5
Chalcogen Atom Size: A Key Parameter in Modulating Carbonyl Compound Properties DOI Creative Commons
Celine Nieuwland, Célia Fonseca Guerra

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 29, 2024

Exchanging oxygen in the functional group C=O (i. e., carbonyl) for less electronegative Group 16 elements, sulfur or selenium, unexpectedly enhances electronegativity of C=X π-conjugated molecules and reduces molecular π HOMO-LUMO energy gap. Quantum-chemical analyses revealed that steric size chalcogen atom X is at origin this seemingly counterintuitive behavior. This tuning chemical properties carbonyl compounds by varying bond can be applied many fields chemistry. concept article delineates several useful applications organocatalysis, supramolecular chemistry, photo(electro)chemistry.

Language: Английский

Citations

1