Synthesis, Photochemical, and Redox Properties of Gold(I) and Gold(III) Pincer Complexes Incorporating a 2,2′:6′,2″-Terpyridine Ligand Framework

Reaction of [Au(C6F5)(tht)] (tht = tetrahydrothiophene) with 2,2′:6′,2″-terpyridine (terpy) leads to complex [Au(C6F5)(η1-terpy)] (1). The chemical oxidation of complex (1) with 2 equiv of [N(C6H4Br-4)3](PF6) or using electrosynthetic techniques affords the Au(III) complex [Au(C6F5)(η3-terpy)](PF6)2 (2). The X-ray diffraction study of complex 2 reveals that the terpyridine acts as tridentate chelate ligand, which leads to a slightly distorted square-planar geometry. Complex 1 displays fluorescence in the solid state at 77 K due to a metal (gold) to ligand (terpy) charge transfer transition, whereas complex 2 displays fluorescence in acetonitrile due to excimer or exciplex formation. Time-dependent density functional theory calculations match the experimental absorption spectra of the synthesized complexes. In order to further probe the frontier orbitals of both complexes and study their redox behavior, each compound was separately characterized using cyclic voltammetry. The bulk electrolysis of a solution of complex 1 was analyzed by spectroscopic methods confirming the electrochemical synthesis of complex 2

An intradialytic non-immersive virtual reality exercise programme: a crossover randomized controlled trial

[EN] Background Chronic kidney disease is closely related to a high risk of death and disability, poor physical performance and frailty. The main objective of this research was to analyse how intradialytic administration of a non-immersive virtual reality (VR) exercise programme would affect physical function and adherence to exercise in these patients. Methods A total of 56 individuals participated in two 12-week periods in a crossover randomized controlled trial. Each patient underwent a functional capacity evaluation before and after each study period. The functional tests administered included the 4-m gait speed test, Short Physical Performance Battery (SPPB), timed up-and-go (TUG) test, one-legged stance test (OLST) for balance, sit-to-stand 10 (STS-10) and sit-to-stand 60 (STS-60) tests and 6-min walking test (6MWT). Adherence to the exercise programme was also recorded. To assess the effect of VR exercise on the functional test outcomes over time, the patients were analysed using a two-way repeated-measures analysis of variance with time and treatment as the within-participant factors. Results By the end of the 12 weeks of exercise, compared with the control period, 33 participants showed significant change in physical function as measured through the 4-m gait speed test (0.14 m/s), SPPB (1.2 points), TUG (-1.7 s), OLST (7.1 s), STS-10 (-5.8 s), STS-60 (5 repetitions) and 6MWT (85.2 m), with adherence rates exceeding 70%. There were no changes in the biochemical data or in the medications in the period of the study. Conclusion An intradialytic non-immersive VR exercise programme improves patient physical function.Funding was received from a research award from the nonprofit organization "Fundacion Renal Tomas de Osma", as well as from a research grant (IDOC 17-19), a research project (FUSP-BS-PPC14/2017) grant from the Universidad Cardenal Herrera-CEU and a research project (PID2019108814RA-I00) from the Spanish Government "Ministerio de Ciencia e Innovación".Martínez-Olmos, FJ.; Gómez-Conesa, AA.; García-Testal, A.; Ortega-Pérez-De-Villar, L.; Valtueña-Gimeno, N.; Gil-Gómez, J.; Garcia-Maset, R.... (2022). An intradialytic non-immersive virtual reality exercise programme: a crossover randomized controlled trial. Nephrology Dialysis Transplantation. 37(7):1366-1374. https://doi.org/10.1093/ndt/gfab2131366137437

1,4-Bis(2'-pyridylethynyl)benzene as a ligand in heteronuclear gold–thallium complexes. Influence of the ancillary ligands on their optical properties

The reaction of 1,4-bis(2’-pyridylethynyl)benzene (L) with [{Au(C6X5)2}Tl]n affords new heterometallic AuI/ TlI complexes with different stoichiometries, structural arrangements and optical properties depending on the halogens present in the aryl group. The chlorinated derivative [{Au(C6Cl5)2}Tl(L)]n (1) displays polymeric chains built thanks to unsupported Au⋯Tl interactions and bridging bidentate ligands between adjacent chains, while in the fluorinated species [{Au(C6F5)2}2Tl2(L)2]n (2), also containing N-donor bridging ligands and Au⋯Tl contacts, polymerization occurs via Tl⋯Caryl non-bonding interactions between neighbouring molecules. The optical properties of 1 and 2 have been studied experimentally and theoretically, conclud- ing that the luminescence of 1 in the solid state has its origin in the Au⋯Tl interactions, and that the Tl⋯Caryl interactions in 2 favour a non-radiative deactivation pathway that avoids luminescence. The strength of the non-bonding interactions present in 1 has also been theoretically studied at the HF and MP2 levels, revealing the metallophilic contact as the strongest one

A User-Friendly System for Mailed Dosimetric Audits of ¹⁹²Ir or ⁶⁰Co HDR Brachytherapy Sources

Objectives: The main goal of this work is to design and characterize a user-friendly methodology to perform mailed dosimetric audits in high dose rate (HDR) brachytherapy for systems using either Iridium-192 (192Ir) or Cobalt-60 (60Co) sources. Methods: A solid phantom was designed and manufactured with four catheters and a central slot to place one dosimeter. Irradiations with an Elekta MicroSelectron V2 for 192Ir, and with a BEBIG Multisource for 60Co were performed for its characterization. For the dose measurements, nanoDots, a type of optically stimulated luminescent dosimeters (OSLDs), were characterized. Monte Carlo (MC) simulations were performed to evaluate the scatter conditions of the irradiation set-up and to study differences in the photon spectra of different 192Ir sources (Microselectron V2, Flexisource, BEBIG Ir2.A85-2 and Varisource VS2000) reaching the dosimeter in the irradiation set-up. Results: MC simulations indicate that the surface material on which the phantom is supported during the irradiations does not affect the absorbed dose in the nanoDot. Generally, differences below 5% were found in the photon spectra reaching the detector when comparing the Microselectron V2, the Flexisource and the BEBIG models. However, differences up to 20% are observed between the V2 and the Varisource VS2000 models. The calibration coefficients and the uncertainty in the dose measurement were evaluated. Conclusions: The system described here is able to perform dosimetric audits in HDR brachytherapy for systems using either 192Ir or 60Co sources. No significant differences are observed between the photon spectra reaching the detector for the MicroSelectron V2, the Flexisource and the BEBIG 192Ir sources. For the Varisource VS2000, a higher uncertainty is considered in the dose measurement to allow for the nanoDot response

Homopolynuclear Tl(I) and heteropolynuclear Au(I)-Tl(I) complexes with organodiselone ligands: activation of the luminescence by intermetallic interactions

The organodiselone ligands 1,1-bis(3-methyl-4-imidazolin-2-selone)methane (L1) and 1,2-bis(3-methyl-4-imidazolin-2-selone)ethane (L2) have been used for the synthesis of homopolynuclear TlI [{Tl(L)}PF6]n·(mMeCN)n [L = L1, m = 1 (1); L = L2, m = 0 (2)] and discrete heteropolynuclear [Tl{Au-(C6Cl5)2}(L)] [L = L1 (3), L2 (4)] complexes. The crystal structures of complexes 1 and 3 have been determined through X-ray diffraction studies. Complex 1 consists of alternating thallium(I) centres and bidentate Se-donor ligands that result in polymeric chains. The crystal structure of 3 is formed by [Tl(L1)]+ cations and [Au(C6Cl5)2]– anions joined together by an unsupported Au···Tl interaction. Compounds 3 and 4 are luminescent in the solid state at room temperature and at 77 K with lifetimes in the nanosecond range. DFT and time-dependent (TD)-DFT calculations have been carried out on different model systems including the free ligand L1, a representative model of complex 1 and a model system of complex 3. The character of the frontier molecular orbitals and the TD-DFT prediction of the absorption spectra are used to explain the origin of the luminescence of complexes 3 and 4 as an admixture of metal–metal (Au–Tl)-to-ligand charge transfer(MMLCT) and intraligand (IL) transitions as observed experimentally