Cu-Fe-S nanocrystals exhibiting a strong localized surface plasmon resonance (LSPR) effect were synthesized for the first time. The elaborated reproducible preparation procedure involved copper(II) oleate, iron(III) stearate, and sulfur powder dissolved in oleylamine (OLA) as precursors. The wavelength of the plasmonic resonance maximum could be tuned by changing the Cu/Fe ratio in the resulting nanocrystals, being the most energetic for the 1:1 ratio (486 nm) and undergoing a bathochromic shift to ca. 1200 nm with an increase to 6:1. LSPR could also be observed in nanocrystals prepared from the same metal precursors and sulfur powder dissolved in 1-octadecene (ODE), provided that the sulfur precursor was taken in excess. Detailed analysis of the reaction mixture by chromatographic techniques, supplemented by mass spectrometry and (1)H NMR spectroscopy enabled the identification of the true chemical nature of the sulfur precursor in S/OLA, namely, (C18H35NH3(+))(C18H35NH-S8(-)), a reactive product of the reduction of elemental sulfur by the amine groups of OLA. In the case of the S/ODE precursor, the true precursors are much less reactive primary or secondary thioethers and dialkyl polysulfides.

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The antimicrobial properties of polycations are strongly affected by the structural features such as the backbone flexibility and topology (isomerism) through the polymer ability to attain proper conformation in interaction with the cell membrane. In this paper, a synthesis and biocidal properties evaluation of ionenes characterized by different backbone topology (isomerism) and flexibility are presented. The findings reveal influence of variation in topology on activity against different microorganisms, and general positive effect of improved flexibility. Furthermore, one of the obtained ionenes displays degradable properties in near physiological environment (phosphate‐buffered saline pH 7.4, 37 °C). The degradation proceeds via Hofmann elimination reaction and the products are not of acidic character. For the first time a new class of degradable ionenes with a high antimicrobial potential is presented.

We propose a novel route for preparation of core–shell nanostructures based on the macroradicals coupling with nitroxides attached to the nanoparticle surface.