[(Z)-N-(3-Fluorophenyl)-O-methylthiocarbamato-κS](triphenylphosphane-κP)gold(I): crystal structure, Hirshfeld surface analysis and computational study

The title phosphanegold(I) thiolate, C26H22AuFNOPS or [Au(C8H7FNOS)(C18H15P)], has the AuI centre coordinated by phosphane-P [2.2494 (8) Å] and thiolate-S [2.3007 (8) Å] atoms to define a close to linear geometry [P—Au—S = 176.10 (3)°]. The thiolate ligand is orientated so that the methoxy-O atom is directed towards the Au atom, forming an Au...O close contact of 2.986 (2) Å. In the crystal, a variety of intermolecular contacts are discerned with fluorobenzene-C—H...O(methoxy) and phenyl-C—H...F interactions leading to dimeric aggregates. These are assembled into a three-dimensional architecture by phenyl-C—H...S(thiolate) and phenyl-C—H...π(fluorobenzene, phenyl) interactions. Accordingly, the analysis of the calculated Hirshfeld surface shows 30.8% of all contacts are of the type C...H/H...C but this is less than the H...H contacts, at 44.9%. Other significant contributions to the surface come from H...F/F...H [8.1%], H...S/S...H [6.9%] and H...O/O...H [3.2%] contacts. Two major stabilization energies have contributions from the phenyl-C—H...π(fluorobenzene) and fluorobenzene-C—H...C(imine) interactions (−37.2 kcal mol−1), and from the fluorobenzene-C—H...F and phenyl-C—H...O interactions (−34.9 kcal mol−1), the latter leading to the dimeric aggregate.

Quality control in ultrasound: an experiment to assess the obsolescence of ultrasound probes with an agar gel phantom

The ultrasound scanner is the most installed equipment in the operating realities but it is not part of precise quality control programs like all other radiological equipment. Considering how many examinations are carried out, it seemed essential to set up intuitive and repeatable QCs, using instruments with low economic impact. The objectives were to test low-cost handmade phantoms to assess the uniformity and sensitivity of the ultrasound probes and the global status of the ultrasound scanners, confirm the goodness of the phantom in terms of use, functionality and storage, then compare the data collected between QC and the global status of the equipment looking for obsolescence causes. 25 linear geometry probes and 19 ultrasound scanners in 10 operating realities undergo quality control. To do this, a phantom in 5% agar-agar and a set of specially designed modules are created. The probes studied showed drops in uniformity and sensitivity already after 3 years with an average of 30 examinations and about 10h of power-on per day. In terms of uniformity, 65% of the probes did not reach acceptability. A condition of poor hygiene was detected in 74% of the ultrasound scanners. The phantom used was homogeneous and isoecogenic in almost all applications according to the professionals.

On the Linear Geometry of Lanthanide Hydroxide (Ln—OH, Ln=La-Lu)

Lanthanide hydroxides are key species in a variety of catalytic processes and in the preparation of corresponding oxides. This work explores the fundamental structure and bonding of the simplest lanthanide hydroxide, LnOH (Ln=La-Lu), using density functional theory calculations. Interestingly, the calculations predict that all structures of this series will be linear. Furthermore, these results indicate a valence electron configuration featuring an occupied sigma orbital and two occupied pi orbitals for all LnOH compounds, suggesting that the lanthanide-hydroxide bond is best characterized as a covalent triple bond.