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Planar bismuth compounds exhibit tunable Lewis acidity and high catalytic activity for lactone polymerization.

With the risks associated with healthcare-associated infections and the rise of antibiotic resistant microorganisms, there is an important need to control the proliferation of these factors in hospitals, retirement homes and other institutions. This work explores the development and application of a novel class of sulfonamide-based quaternary ammonium antimicrobial coatings, anchored to commercially and clinically relevant material surfaces. Synthesized in high yields (60–97%), benzophenone-anchored antimicrobials were spray-coated and UV grafted onto plastic surfaces, while silane-anchored variants were adhered to select textiles via dip-coating. Surface modified samples were characterised by advancing contact angle, anionic dye staining, X-ray photoelectron spectroscopy and atomic force microscopy. After verifying coating quality through the above characterization methods, microbiological testing was performed on batch samples in conditions that simulate the natural inoculation of surfaces and objects (solid/air) and water containers (solid/liquid). Using the previously established Large Drop Inoculum (LDI) protocol at solid/air interfaces, all treated samples showed a full reduction (105–107 CFU) of viable Arthrobacter sp., S. aureus, and E. coli after 3 h of contact time. Additional testing of the walls of plastic LDPE vials treated with a UV-cured sulfonamide antimicrobial at a solid/liquid interface using the newly developed Large Reservoir Inoculum (LRI) protocol under static conditions revealed a complete kill (>106 reduction) of Gram-positive Arthrobacter sp., and a partial kill (>104 reduction) of Gram-negative E. coli within 24–48 h of contact.

The threat of antibiotic-resistant, biofilm-forming bacteria necessitates a preventative approach to combat the proliferation of robust, pathogenic strains on "high touch surfaces" in the food packaging, biomedical, and healthcare industries. The development of both biocide-releasing and tethered, immobilized biocide surface coatings has risen to meet this demand. While these surface coatings have demonstrated excellent antimicrobial efficacy, there are few examples of antimicrobial surfaces with long-term durability and performance. To this end, UV-curable phosphoniums bearing benzophenone anchors with either an alkyl, aryl, or fluoroalkyl group were synthesized and their efficacy as thermally stable antimicrobial additives in extruded plastics or as surface attached coatings probed. The surface topology and characteristics of these materials were studied to gain insight into the mechanism of their antimicrobial activity. Efficacy against both Gram negative and Gram positive bacteria as either a coating or additive showed compete reductions of the initial bacterial load. Crucially, the materials maintained the ability to kill biofilm-forming bacteria even after being subject to several cycles of abrasion.

Tetraarylmethanes and adamantanes are important rigid covalent connectors that play a four-way scaffolding role in molecular and materials chemistry. We report the synthesis of a new tetravalent phosphaza-adamantane cage, (PNSiMe

Tetraarylmethanes and adamantanes are very rare examples of rigid, four-way, anionic connectors that play a scaffolding role in multiple areas of molecular and materials chemistry. We report the synthesis of a tetravalent phosphaza-adamantane cage, (PNSiMe3)4(NMe)6 (2), that shows unusually high ambient, thermal, and redox stability due to its unique geometry. It nevertheless participates in four-fold functionalization reactions on its periphery. The combination of a robust core but a reactive corona makes 2 a convenient inorganic scaffold upon which tetrahedral molecular and macromolecular chemistry can be reliably constructed. This potential is exemplified by the unprecedented synthesis of a tetracationic tetraphosphinimine (3) and the first porous all-P/N polyphosphazene network (5).

With the risks associated with healthcare-associated infections and the rise of antibiotic resistant microorganisms, there is an important need to control the proliferation of these factors in hospitals, retirement homes and other institutions. This work explores the development and application of a novel class of sulfonamide-based quaternary ammonium antimicrobial coatings, anchored to commercially and clinically relevant material surfaces. Synthesized in high yields (60–97%), benzophenone-anchored antimicrobials were spray-coated and UV grafted onto plastic surfaces, while silane-anchored variants were adhered to select textiles via dip-coating. Surface modified samples were characterised by advancing contact angle, anionic dye staining, X-ray photoelectron spectroscopy and atomic force microscopy. After verifying coating quality through the above characterization methods, microbiological testing was performed on batch samples in conditions that simulate the natural inoculation of surfaces and objects (solid/air) and water containers (solid/liquid). Using the previously established Large Drop Inoculum (LDI) protocol at solid/air interfaces, all treated samples showed a full reduction (105–107 CFU) of viable Arthrobacter sp., S. aureus, and E. coli after 3 h of contact time. Additional testing of the walls of plastic LDPE vials treated with a UV-cured sulfonamide antimicrobial at a solid/liquid interface using the newly developed Large Reservoir Inoculum (LRI) protocol under static conditions revealed a complete kill (>106 reduction) of Gram-positive Arthrobacter sp., and a partial kill (>104 reduction) of Gram-negative E. coli within 24–48 h of contact.

Magnetoelectric (ME) composites can be produced by embedding magnetostrictive H particles in a piezoelectric E matrix derived from a piezoelectric powder precursor. Previously, using a bi-disperse hard-shell model (Barbero and Bedard in Comput Part Mech, 2018. https://doi.org/10.1007/s40571-017-0165-4 ), it has been shown that the electrical percolation threshold of the conductive H phase can be increased by decreasing the piezoelectric E particle size, relative to the H phase particle size, and by increasing short-range affinity between the E and H particles. This study builds on our previous study by exploring what happens during sintering of the ME composite when either the H or E particles undergo deformation. It was found that deformation of the H particles reduces the percolation threshold, and that deformation of E particles increases inter-phase H–E mechanical coupling, thus contributing to enhancing of ME coupling.

Magnetoelectric composites can be produced by embedding magnetostrictive particles in a piezoelectric matrix derived from a piezoelectric powder precursor. Ferrite magnetostrictive particles, if allowed to percolate, can short the potential difference generated in the piezoelectric phase. Modeling a magnetoelectric composite as an aggregate of bi-disperse hard shells, molecular dynamics was used to explore relationships among relative particle size, particle affinity, and electrical percolation with the goal of maximizing the percolation threshold. It is found that two factors raise the percolation threshold, namely the relative size of magnetostrictive to piezoelectric particles, and the affinity between the magnetostrictive and piezoelectric particles.

A library of precursor and functionally active quaternary ammonium cations (QACs) for use as corrosion resistant and or antimicrobial coatings, or alternatively as polymer modifiers, is described. High yielding and improved routes to a series of functionally terminated allyl ([(CH2=CH-CH2)m-N+(Me)n-C18H37][X−], 1: m=1, n=2, X−=Br−, 3: m=2, n=1, X−=I−, 4: m=3, n=0, X−=Br−) vinyl ([CH2=CHCH2CH2-N+Me2-C18H37][Br−] 5), hydroxy ([HO-(CH2)m-N+Me2-C18H37][Br−], 6: m=3, 7: m=4), haloalkyl ([X1-(CH2)3-N+Me2-C18H37][X−] 8: X1=Br, X=Br−, 9: X1=Cl, X=I−), dimethoxyphenethyl ([(MeO)2C6H3(CH2)2-N+Me2-C18H37][Br−], 11), acetamido ([H3C(O)NH-(CH2)3-N+Me2-C18H37][Cl−], 12) cyano ([N≡C–CH2-N+Me2-C18H37][Cl−], 13), organocarbonylamino ([R-C(O)2NH-(CH2)3-N+Me2-C18H37][Br−], 14: R=t-Bu-, 15: R=PhCH2-), phthalimido ([PhthN-(CH2)3-N+Me2-C18H37][Br−], 16), amino ([H2N-(CH2)3-N+Me2-C18H37][Br−] 17), acetylthio ([HC(O)S-(CH2)3-N+Me2-C18H37][Cl−], 18), thiol ([HS-(CH2)3-N+Me2-C18H37][Cl−] 19), disulfa ([-S-(CH2)2-N+Me2-C18H37]2[Br−]2, 20) C18 QACs prepared by thermal and or microwave driven Menshutkin reactions are detailed. All new compounds were characterized by NMR spectroscopy, HRMS spectrometry and in the case of 1 and 6 by X-ray crystallography.

A series of UV active benzophenone ([C6H5COC6H4-O-(CH2)n-N+Me2R][X–]; 4, R = C12H25, n = 3, X– = Br–; 5a–c, R = C18H37, n = 3, X– = Cl–, Br–, I–; 6a–c, R = C18H37, n = 4, X– = Cl–, Br–, I–; 7a–c, R = C18H37, n = 6, X– = Cl–, Br–, I–) terminated C12 and C18 quaternary ammonium salts (QACs) were prepared by thermal or microwave-driven Menshutkin protocols of the appropriate benzophenone alkyl halide (1a–c, 2a–c, 3a–c) with the corresponding dodecyl- or octadecyl N,N-dimethylamine. All new compounds were characterized by NMR spectroscopy, HRMS spectrometry, and, in one instance (4), by single-crystal X-ray crystallography. Representative C12 and C18 benzophenone QACs were formulated into 1% (w/v) water or water/ethanol-based aerosol spray coatings and then UV-cured onto plastic substrates (polypropylene, polyethylene, polystyrene, polyvinyl chloride, and polyether ether ketone) with exposure to low to moderate doses of UV (20–30 J cm–2). Confirmation as to the presence of the coatings was detected by advanci...