Eleven bis-ureas have been synthesized, and some of their properties are reported. Several of these compounds form supramolecular polymers in organic solvents. The self-association is shown by FTIR spectroscopy to display cooperativity at two levels. The first level of cooperativity is due to the synergistic association of the two urea functions of a single molecule. The second level of cooperativity is revealed by the fact that the formation of dimers is less favored than that of long oligomers.
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http://dx.doi.org/10.1021/ja037589x | DOI Listing |
ACS Appl Bio Mater
January 2025
Regenerative Medicine and Stem Cell Laboratory (RMS), Department of Biomedical Engineering, Indian Institute of Technology Hyderabad, Kandi 502 284, Telangana, India.
Despite advancements in chronic arthritis treatment, there remains a significant demand for advanced nanotechnologies capable of efficiently delivering a wide range of therapeutic agents to provide symptomatic relief and facilitate the healing of inflamed cartilage tissue. Considering the significant impact of hypoxia on the development and maintenance of chondral tissue, replicating its effects on stem cells could be a potential approach for the treatment of osteoarthritis (OA). Cobalt is a prominent hypoxia-inducing agent, owing to its ability to activate the hypoxia-inducible factor (HIF) pathway regardless of cellular oxygen levels.
View Article and Find Full Text PDFInorg Chem
January 2025
Department of Chemistry, Jadavpur University, Kolkata, West Bengal 700032, India.
Pyrazine (tppz) and 5-sulfosalicylic acid (HSSA) mixed-bridging Cd(II)-CP, {[Cd(HSSA)(tppz)]} (), is highly luminescent, and the emission has been quenched selectively by Al in the presence of other cations, with a limit of detection (LOD) of 43.9 nM (1.18 ppb).
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
IITH: Indian Institute of Technology Hyderabad, Chemistry, Kandi, Sangaredddy, 502285, INDIA.
A squaramide-based monomer, designed for topochemical azide-alkyne cycloaddition (TAAC) polymerization, crystallizes as two polymorphs, M1 and M2, both having crystal packing suitable for topochemical polymerization. The hydrogen-bonding between squaramide units bias the molecular organization in both the polymorphs. 3D packing of H-bonded stacks of monomer lead to juxtaposition of azide and alkyne units of adjacent molecules in a transition-state-like arrangement for their regiospecific cycloaddition reaction.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
Computationally designed 29-residue peptides yield tetra-α-helical bundles with symmetry. The "bundlemers" can be bifunctionally linked via thiol-maleimide cross-links at their N-termini, yielding supramolecular polymers with unusually large, micrometer-scale persistence lengths. To provide a molecularly resolved understanding of these systems, all-atom molecular modeling and simulations of linked bundlemers in explicit solvent are presented.
View Article and Find Full Text PDFDalton Trans
January 2025
Department of Inorganic Chemistry, Shahid Beheshti University, 1983969411, Tehran, Iran.
In a systematic study, six pseudopolymorphic coordination polymers containing the ditopic 1,3-di(pyridin-4-yl)urea ligand (4bpu) constructed with d metal cations, possessing the formula {[M(4bpu)I]S} [(M = Zn, Cd and Hg), (S = MeOH or EtOH)], namely Zn-MeOH, Zn-EtOH, Cd-MeOH, Cd-EtOH, Hg- and Hg-EtOH were obtained. The title compounds were characterized by single-crystal X-ray diffraction analysis (SC-XRD), elemental analysis (CHN), FT-IR spectroscopy, thermogravimetric analysis (TGA), and powder X-ray diffraction (PXRD). The diffraction studies show that these compounds are isostructural 1D zig-zag chain coordination polymers which is also confirmed using XPac 2.
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