In the Pursuit of Efficient Anion-Binding Organic Ligands Based on Halogen Bonding

The syntheses and the crystal structures of new multitopic anion-binding organic ligands based on a benzenoid scaffold and bearing two or three 2-iodo-imidazolium arms are reported. The quite short C–I···Br¯ contacts observed in the solid state (0.77 times the normalized contacts) demonstrate the excellent halogen bonding donor ability of iodine atoms in 2-iodoimidazolium cations. The geometric features of obtained bromide anion adducts afford valuable structural insights for the design of effective and selective multitopic anion receptors based on halogen bonding

Halogen Bonding and Pharmaceutical Cocrystals: The Case of a Widely Used Preservative

3-Iodo-2-propynyl-<i>N</i>-butylcarbamate (IPBC) is an iodinated antimicrobial product used globally as a preservative, fungicide, and algaecide. IPBC is difficult to obtain in pure form as well as to handle in industrial products because it tends to be sticky and clumpy. Here, we describe the preparation of four pharmaceutical cocrystals involving IPBC. The obtained cocrystals have been characterized by X-ray diffraction, solution and solid-state NMR, IR, and DSC analyses. In all the described cases the halogen bond (XB) is the key interaction responsible for the self-assembly of the pharmaceutical cocrystals thanks to the involvement of the 1-iodoalkyne moiety of IPBC, which functions as a very reliable XB-donor, with both neutral and anionic XB-acceptors. Most of the obtained cocrystals have improved properties with respect to the source API, in terms, e.g., of thermal stability. The cocrystal involving the GRAS excipient CaCl₂ has superior powder flow characteristics compared to the pure IPBC, representing a promising solution to the handling issues related to the manufacturing of products containing IPBC

A Superfluorinated Molecular Probe for Highly Sensitive <i>in Vivo</i>¹⁹F‑MRI

¹⁹F-MRI offers unique opportunities to image diseases and track cells and therapeutic agents <i>in vivo</i>. Herein we report a superfluorinated molecular probe, herein called <b>PERFECTA</b>, possessing excellent cellular compatibility, and whose spectral properties, relaxation times, and sensitivity are promising for <i>in vivo</i>¹⁹F-MRI applications. The molecule, which bears 36 equivalent ¹⁹F atoms and shows a single intense resonance peak, is easily synthesized via a simple one-step reaction and is formulated in water with high stability using trivial reagents and methods

A Short-Chain Multibranched Perfluoroalkyl Thiol for More Sustainable Hydrophobic Coatings

Perfluorocarbons (PFCs) have proven to be very efficient in building up omniphobic surfaces because of the peculiar properties of fluorine atoms. However, due to their environmental impact and bioaccumulative potential, perfluorinated surfactants with chains longer than six carbon atoms have been banned, and other alternatives had to be found. Herein, we demonstrate the possibility to build omniphobic self-assembled monolayers (SAMs) using a multibranched fluorinated thiol (BRFT) bearing ultrashort fluorinated alkyl groups, surrounding a hydrocarbon polar core. This unique design allows us to multiply the number of fluorine atoms in the molecule (27 F atoms per molecule), affording a high fluorine density on the surface and a low surface free energy. Moreover, the presence of four ether bonds in the core may hasten molecular degradation in the environment because of the cleavage of such bonds in physiological conditions, thus overcoming bioaccumulation issues. BRFT may effectively represent a valuable substitute of long-chain perfluoroalkyl thiols. In fact, BRFT SAMs show the same hydrophobic and oleophobic performances of standard linear perfluoroalkyl thiols (such as 1H,1H,2H,2H-perfluorodecanethiol, PFDT), giving rise to more stable surfaces with a better frictional behavior. Superhydrophobicity was also observed with SAMs grown on nanostructured Cu/Ag surfaces. Our results have proven the ability of short-chain multibranched fluorous molecules to behave as suitable replacements for long-chain perfluoroalkanes in the field of surface coatings. Our molecules may be applied to various surfaces because of the available multiple choice of linker chemistry