Halogen bonding has been used to glue together hydrogen-bonded short arylamide foldamers to achieve new supramolecular double and quadruple helices in the solid state. Three compounds, which bear a pyridine at one end and either a CF I or fluorinated iodobenzene group at the other end, engage in head-to-tail N⋅⋅⋅I halogen bonds to form one-component supramolecular P and M helices, which stack to afford supramolecular double-stranded helices. One of the double helices can dimerize to form a G-quadruplex-like supramolecular quadruple helix. Another symmetric compound, which bears a pyridine at each end, binds to ICF CF I through N⋅⋅⋅I halogen bonds to form two-component supramolecular P and M helices, with one turn consisting of four (2+2) molecules. Half of the pyridine-bearing molecules in two P helices and two M helices stack alternatingly to form another supramolecular quadruple helix. Another half of the pyridine-bearing molecules in such quadruple helices stack alternatingly with counterparts from neighboring quadruple helices, leading to unique quadruple helical arrays in two-dimensional space.
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http://dx.doi.org/10.1002/anie.201811561 | DOI Listing |
ACS Macro Lett
January 2025
School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai 200240, P. R. China.
Stimuli-responsive polymers have demonstrated significant potential in the development of smart materials due to their capacity to undergo targeted property changes in response to external physical or chemical stimuli. However, the scales of response in most existing stimuli-responsive polymer systems are mainly focused on three levels: functional units, chain conformations, or polymer topologies. Herein, we have developed a covalent polymer network (CPN) capable of converting into a supramolecular polymer network (SPN) within bulk materials directly at the scale of polymer network types.
View Article and Find Full Text PDFJ Chem Theory Comput
January 2025
Biophysics Graduate Program, The Ohio State University, Columbus, Ohio 43210, United States.
Fragment-based quantum chemistry methods offer a means to sidestep the steep nonlinear scaling of electronic structure calculations so that large molecular systems can be investigated using high-level methods. Here, we use fragmentation to compute protein-ligand interaction energies in systems with several thousand atoms, using a new software platform for managing fragment-based calculations that implements a screened many-body expansion. Convergence tests using a minimal-basis semiempirical method (HF-3c) indicate that two-body calculations, with single-residue fragments and simple hydrogen caps, are sufficient to reproduce interaction energies obtained using conventional supramolecular electronic structure calculations, to within 1 kcal/mol at about 1% of the computational cost.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States.
We present a six-step cascade that converts 1,3-distyrylbenzenes (-stilbenes) into nonsymmetric pyrenes in 40-60% yields. This sequence merges photochemical steps, ,-alkene isomerization, a 6π photochemical electrocyclization (Mallory photocyclization); the new bay region cyclization, with two radical iodine-mediated aromatization steps; and an optional aryl migration. This work illustrates how the inherent challenges of engineering excited state reactivity can be addressed by logical design.
View Article and Find Full Text PDFRSC Adv
November 2024
Faculty of Chemistry and Chemical Engineering, Yunnan Normal University Kunming 650500 China +86 871 65941088 +86 871 65941087.
Two categories of supramolecular polymer monomers were produced by introducing the ureidopyrimidone quadruple-hydrogen bonding assemblies on the calix[4]arene and the β-cyclodextrin host units. The adsorption capacity of these supramolecular polymers for different metal ions was investigated by static adsorption. The results showed that at pH = 6 and when the adsorption equilibrium was reached, the supramolecular polymer with calixarene and β-cyclodextrin as the main body adsorbed up to 99% of Pb and Cd, respectively.
View Article and Find Full Text PDFJ Mater Chem B
December 2024
Supramolecular Chemistry Group, Centre of Macromolecular Chemistry (CMaC), Department of Organic and Macromolecular Chemistry, Ghent University, B-9000 Ghent, Belgium.
Dynamic polymer materials can be obtained by introducing supramolecular interactions between the polymer chains. Here we report on the preparation and mechanical properties of poly(methyl acrylate) (PMA) and poly(-butyl acrylate) (PBA) funcionalized with ureidopyrimidinone (UPy) in the side chains. In contrast to the traditional UPy with a methyl group, the selected UPy motif contained a branched alkyl side chain, which enhances solubility, compatibility with the polymer matrix and potentially prevents stacking of UPy dimers.
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