Multinuclear silver(I) XPhos complexes with cyclooctatetraene: photochemical C-C bond cleavage of acetonitrile and cyanide bridged Ag cluster formation

[EN] Cationic mono-, di-, tri-and tetra-nuclear silver complexes with Buchwald-type phosphane (XPhos) and cyclooctatetraene (COT) have been synthesized and characterized. Formation of [(XPhos-Ag) n(COT)][SbF6](n) (n = 1 and 2) complexes was confirmed by single-crystal X-ray crystallography and multinuclear NMR spectroscopy. Variable-temperature NMR spectroscopy in CD2Cl2 solution shows the fluxionality of the COT ring in the mono-Ag(I) XPhos complex. Fluxionality of COT was also confirmed in the case of the di-Ag(I) XPhos complex by solid-state and solution P-31 NMR spectroscopy. The C-C bond cleavage of coordinated acetonitrile [XPhos-Ag(I)-NCCH3] resulting in cyanide bridged Ag cluster formation [(XPhos-Ag)(2)(mu-CN)(n)(mu-Ag)(n-1)] (n = 1, 2, 3 and 4) upon light excitation of [(XPhos-Ag)(n)(COT)] was confirmed by HRESI-MS, UV-Absorption and HR-TEM.Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa and CTQ2015-69153-C2-1-R) and Generalidad Valenciana (Prometeo 2013-014) is gratefully acknowledged. We also thank Dr Vidal-Moya J. A. (ITQ) for assistance and discussions on NMR analysis.Grirrane ., A.; Alvarez-González, E.; Albero-Sancho, J.; García Gómez, H.; Corma Canós, A. (2016). Multinuclear silver(I) XPhos complexes with cyclooctatetraene: photochemical C-C bond cleavage of acetonitrile and cyanide bridged Ag cluster formation. Dalton Transactions. 45(13):5444-5450. https://doi.org/10.1039/c6dt00370bS54445450451

Novel genes and sex differences in COVID-19 severity.

Here we describe the results of a genome-wide study conducted in 11 939 COVID-19 positive cases with an extensive clinical information that were recruited from 34 hospitals across Spain (SCOURGE consortium). In sex-disaggregated genome-wide association studies for COVID-19 hospitalization, genome-wide significance (p < 5x10-8) was crossed for variants in 3p21.31 and 21q22.11 loci only among males (p = 1.3x10-22 and p = 8.1x10-12, respectively), and for variants in 9q21.32 near TLE1 only among females (p = 4.4x10-8). In a second phase, results were combined with an independent Spanish cohort (1598 COVID-19 cases and 1068 population controls), revealing in the overall analysis two novel risk loci in 9p13.3 and 19q13.12, with fine-mapping prioritized variants functionally associated with AQP3 (p = 2.7x10-8) and ARHGAP33 (p = 1.3x10-8), respectively. The meta-analysis of both phases with four European studies stratified by sex from the Host Genetics Initiative confirmed the association of the 3p21.31 and 21q22.11 loci predominantly in males and replicated a recently reported variant in 11p13 (ELF5, p = 4.1x10-8). Six of the COVID-19 HGI discovered loci were replicated and an HGI-based genetic risk score predicted the severity strata in SCOURGE. We also found more SNP-heritability and larger heritability differences by age (<60 or ≥ 60 years) among males than among females. Parallel genome-wide screening of inbreeding depression in SCOURGE also showed an effect of homozygosity in COVID-19 hospitalization and severity and this effect was stronger among older males. In summary, new candidate genes for COVID-19 severity and evidence supporting genetic disparities among sexes are provided