Using trimesic acid (TMA) as a model system by means of scanning tunneling microscope (STM) equipped with a temperature controller, here, we report a temperature-assisted method to cooperatively control electric-field-induced supramolecular phase transitions at the liquid/solid interface. Octanoic acid is used as a solvent due to its good solubility for TMA and its less complicated pattern formed under negative STM bias (e.g., only chicken-wire polymorphs existing). At positive substrate bias, STM revealed that TMA assembly based on temperature modulations underwent phase transitions from a porous (22 °C) to a flower (45 °C) and further to a zigzag (68 °C) structure. The transitions are ascribed to the partial deprotonation of the carboxyl groups of TMA. Both the temperature and electrical polarity of the substrate are crucial, i.e., the transitions only take place at positive substrate bias and elevated temperatures. Molecular mechanics simulations were carried out to calculate the temperature and electric field dependence of the adsorption enthalpy and free energy of the chicken-wire assembly of TMA on the two layers of graphene surface. The calculated decrease in adsorption enthalpy with the increase of temperature and electric field values that causes the TMA chicken-wire assembly to be less stable is proposed to promote the occurrence of the phase transition observed by STM. This study paves the way toward program-controlled supramolecular phase switching via the synergic effect of electrical and thermal stimuli.
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http://dx.doi.org/10.1021/acs.langmuir.9b00569 | DOI Listing |
J Phys Chem C Nanomater Interfaces
January 2025
Furman University, Greenville, South Carolina 29613, United States.
Surface-anchored metal-organic frameworks (surMOFs) are crystalline, nanoporous, supramolecular materials mounted to substrates that have the potential for integration within device architectures relevant for a variety of electronic, photonic, sensing, and gas storage applications. This research investigates the thin film formation of the Cu-BDC (copper benzene-1,4-dicarboxylate) MOF system on a carboxylic acid-terminated self-assembled monolayer by alternating deposition of solution-phase inorganic and organic precursors. X-ray diffraction (XRD) and atomic force microscopy (AFM) characterization demonstrate that crystalline Cu-BDC thin films are formed via Volmer-Weber growth.
View Article and Find Full Text PDFJ Mater Chem B
January 2025
Department of Textile and Fibre Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110016, India.
In recent years, the development of biodegradable, cell-adhesive polymeric implants and minimally invasive surgery has significantly advanced healthcare. These materials exhibit multifunctional properties like self-healing, shape-memory, and cell adhesion, which can be achieved through novel chemical approaches. Engineering of such materials and their scalability using a classical polymer network without complex chemical synthesis and modification has been a great challenge, which potentially can be resolved using biobased dynamic covalent chemistry (DCC).
View Article and Find Full Text PDFDalton Trans
January 2025
Institute of Chemistry, St Petersburg University, Universitetskii pr. 26, 198504 St. Petersburg, Russia.
A series of cyclometalated Au(III) complexes [Au(C^N^C)(C-L-P(O)Ph)] with C^N^C = 2,6-diphenylpyridine and alkynylphosphine oxide ligands (L = no linker, Au1; phenyl, Au2; biphenyl, Au3; naphthyl, Au4; anthracenyl, Au5) were synthesized and fully characterized by spectroscopic methods and single crystal XRD analysis. The complexes obtained exhibit triplet (Au1-Au3) and dual (Au4, Au5) emissions in solution, in the solid phase and in the PMMA film, whose characteristics depend on the linker's nature of the alkynylphosphine oxide ligand. The description of electronic transitions responsible for energy absorption and emission in Au(III) complexes was made on the basis of a detailed analysis of the results of DFT calculations and has shown to involve ILCT, LLCT and MLCT transitions of singlet and triplet nature.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Department of Chemistry, University of Sherbrooke, 2500, Blvd de l'Université, Sherbrooke, QC J1K 2R1, Canada.
This study delves into the distinctive selective property exhibited by a non-conjugated cholesterol-based polymer, poly(CEM--EHA), in sorting semiconducting single-walled carbon nanotubes (s-SWCNTs) within isooctane. Comprised of 11 repeating units of cholesteryloxycarbonyl-2-hydroxy methacrylate (CEM) and 7 repeating units of 2-ethylhexyl acrylate (EHA), this non-conjugated polymer demonstrates robust supramolecular interactions across the sp surface structure of carbon nanotubes and graphene. When coupled with the Double Liquid-Phase Extraction (DLPE) technology, the polymer effectively segregates s-SWCNTs into the isooctane phase (nonpolar) while excluding metallic SWCNTs (m-SWCNTs) in the water phase (polar).
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January 2025
Department of Chemistry, Universitat de les Illes Balears, Crta de Valldemossa km 7.5, 07122 Palma de Mallorca, Baleares, Spain.
This perpective delves into the emerging field of matere bonds, a novel type of noncovalent interaction involving group 7 elements such as manganese, technetium, and rhenium. Matere bonds, a new member of the σ-hole family where metal atoms act as electron acceptors, have been shown experimentally and theoretically to play significant roles in the self-assembly and stabilization of supramolecular structures both in solid-state and solution-phase environments. This perspective article explores the physical nature of these interactions, emphasizing their directionality and structural influence in various supramolecular architectures.
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