We demonstrate herein a computational study probing the influence of metalloporphyrins on intermolecular halogen bonding (XB) during supramolecular self-assembly. The results demonstrate that porphyrin aromatic rings can activate or deactivate halogen bonding interactions, especially those on axial ligands, and further influence the preference type of halogen···halogen bonding during the supramolecular self-assembly. Calculations show that the halogen atom present at the equatorial position has a higher sigma hole potential (V) than that at the axial position. The computational analysis and our observations from the X-ray structure analysis are in good agreement. From structural analysis it is clear that equatorial halogen atoms prefer to participate in Type-II XB interactions whereas the axial halogen atoms either participate in Type-I XB interaction or reluctant to participate in XB interactions due to the decrease of their sigma hole potential. Thus, we demonstrate, herein, for the first time a computational study probing the direct influence of the porphyrin's ring current on the sigma hole potential (V) of the halogen atoms and subsequently the effects of the supramolecular self-assembly.
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http://dx.doi.org/10.1039/d0cp00351d | DOI Listing |
Chemistry
December 2024
Department of Nephrology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatric Metabolism and Inflammatory Diseases, Chongqing, 400042, China.
In this study, a supramolecular fluorescent material was constructed by using double-cavity twisted cucurbit[14]uril (tQ[14]) and positively charged Astrazon Pink FG (APFG) based on the non-covalent host-guest interaction for the first time. The thermodynamic parameters of the APFG@tQ[14] in aqueous solution were determined by isothermal titration calorimetry (ITC), the results indicated that the spontaneous assembly of APFG@tQ[14] is mainly driven by enthalpy. The intramolecular charge transfer (ICT) effect induced the APFG@tQ[14] probe to emit a strong orange-red fluorescence.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2025
State Key Laboratory of Green Pesticide, Central China Normal University, Wuhan 430079, PR China. Electronic address:
The construction of helical structures through self-assembly and the exploration of their formation mechanisms not only amplify chiroptical properties but also provide profound insights into the structures and functions of natural helices. In this study, we developed a chiral Au(I) system based on BINAP and alkynyl ligands. The modification of the length or number of alkyl chains at the terminal positions of the alkynyl ligands significantly impacted the self-assembly behavior of the complexes.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
SKKU Advanced Institute of Nanotechnology (SAINT), Department of Nano Engineering, Department of Nano Science and Technology, School of Chemical Engineering, Biomedical Institute for Convergence at SKKU, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Republic of Korea.
Despite their safety and widespread use, conventional protein antigen-based subunit vaccines face significant challenges such as low immunogenicity, insufficient long-term immunity, poor CD8 T-cell activation, and poor adaptation to viral variants. To address these issues, an infection-mimicking gel (IM-Gel) is developed that is designed to emulate the spatiotemporal dynamics of immune stimulation in acute viral infections through in situ supramolecular self-assembly of nanoparticulate-TLR7/8a (NP-TLR7/8a) and an antigen with tannic acid (TA). Through collagen-binding properties of TA, the IM-Gel enables sustained delivery and enhanced retention of NP-TLR7/8a and protein antigen in the lymph node subcapsular sinus of mice for over 7 days, prolonging the exposure of vaccine components in both B cell and T cell zones, leading to robust humoral and cellular responses.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
TU Dortmund University, Faculty for Chemistry and Chemical Biology, Otto-Hahn-Str. 6, 44227, Dortmund, GERMANY.
Precise control over the catenation process in interlocked supramolecular systems remains a significant challenge. Here, we report a system in which a lantern-shaped Pd2L4 cage can dimerize to form two distinct Pd4L8 catenanes with different interlocking degree: a previously described quadruply interlocked double cage motif of D4 symmetry and an unprecedented triply interlocked structure of C2h symmetry. While the former structure features a linear arrangement of four Pd(II) centers, separated by three mechanically linked pockets, the new motif has a staggered shape.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Laboratoire Softmat, UMR au CNRS no 5623, Université Paul Sabatier, F-31062 Toulouse, France.
Simulations on an ODE-based model shows that there are many common points between Viedma deracemization and chiral self-assemblies of achiral building blocks towards chiral nanoparticles. Both systems occur in a closed system with energy exchange but no matter exchange with the surroundings and show parallel reversible growth mechanisms which coexist with an irreversible cluster breaking (grinding). The various mechanisms of growth give rise to the formation of polymerization/depolymerization cycles while the consecutive transformation of achiral monomer into chiral cluster results into an indirect enantioselective autocatalysis.
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