Prospects for terahertz imaging the human skin cancer with the help of gold-nanoparticles-based terahertz-to-infrared converter

The design is suggested, and possible operation parameters are discussed, of an instrument to inspect a skin cancer tumour in the terahertz (THz) range, transferring the image into the infrared (IR) and making it visible with the help of standard IR camera. The central element of the device is the THz-to-IR converter, a Teflon or silicon film matrix with embedded 8.5 nm diameter gold nanoparticles. The use of external THz source for irradiating the biological tissue sample is presumed. The converter's temporal characteristics enable its performance in a real-time scale. The details of design suited for the operation in transmission mode (in vitro) or on the human skin in reflection mode {in vivo) are specified.Comment: To be published in the proceedings of the FANEM2018 workshop - Minsk, 3-5 June 201

Controlled Halogen-Bond-Involving Assembly of Double-sigma-Hole-Donating Diaryliodonium Cations and Ditopic Arene Sulfonates

The supramolecular dimensionality of halogen bonded architectures formed in the solid state by diaryliodonium salts is greater when the anion is a disulfonate rather than a monosulfonate. Specifically, diaryliodonium cations conventionally function as double-sigma-hole halogen bond (XB) donors and form 0D-heterotetrameric motifs when paired with monosulfonate anions. Here it is reported that when 1,5- and 2,6-naphthalenedisulfonate anions are used as ditopic XB acceptors, their assemblies with diaryliodonium cations provide architectures of higher dimensionality. 1,5-Naphthalenedisulfonate leads to the occurrence of 1D chains, while the longer and less sterically encumbered 2,6-naphthalenedisulfonate produces either 1D chains or 2D layers. The two-center I center dot center dot center dot OSO supramolecular synthon is observed most frequently, and the three-center I center dot center dot center dot OSO linkage was identified in some assemblies based on 2,6-naphthalenedisulfonate

Benzothienoiodolium Cations Doubly Bonded to Anions via Halogen-Chalcogen and Halogen-Hydrogen Supramolecular Synthons

The simultaneous binding of a molecular entity through two interactions is a frequently pursued recognition mode due to the advantages it offers in securing molecular self-assembly. Here, we report how the planarity of the benzothienoiodolium (BTI) cation allows for preorganizing in the cation plane the hydrogen, halogen, and chalcogen bonds (HBs, XBs, and ChBs, respectively) formed by the phenyl hydrogen, iodolium iodine, and thienyl sulfur. Crystallographic analyses of some BTI salts show how this interaction coplanarity enables their coupling to point toward a single anion that is coordinated via the supramolecular and heteroditopic synthon XB/HB or XB/ChB, the latter observed here for the first time. These synthons adopt a Janus-like arrangement around iodine. Crystallographic information suggests that interactions of the synthons act synergistically, e.g., when resulting in the unusually short ChBs formed by the thienyl sulfur. Determination of the molecular electrostatic potential, Bader's quantum theory of "atoms-in-molecules" analysis, and natural bond orbital investigations give information on the nature and energetic aspects of the short contacts observed in crystals