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A new mixed hexaphyrin, pyrihexaphyrin (0.1.0.0.1.0) (), was prepared an acid catalyzed cyclization between 5,5'-(pyridine-2,6-diyl)bis(pyrrole-2-carbaldehyde) () and terpyrrole (). This expanded porphyrin undergoes a ring contraction upon metallation with uranyl silylamide [UO[N(SiMe)]] under anaerobic conditions followed by purification over basic aluminum oxide exposed to air. The uranyl-contracted pyrihexaphyrin (0.0.0.0.1.0) complex () produced as a result contains a unique structural architecture and possesses a formally 22 π-electron globally aromatic periphery, as inferred from NMR spectroscopy, single crystal X-ray diffraction, and computational analyses. Support for the proposed contraction mechanism came from experimental data and DFT calculations. Proton NMR and mass spectroscopic analysis provided the first insight into expanded porphyrin-mediated activation of the uranyl dication (UO ).
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http://dx.doi.org/10.1039/c9sc01593k | DOI Listing |
J Chem Phys
September 2025
Jülich Centre for Neutron Science (JCNS-1), Forschungszentrum Jülich GmbH, 52428 Jülich, Germany.
The static and dynamic properties of a cyclic Rouse chain modified by the introduction of an effective, spherically symmetric, attracting potential of entropic nature are studied. It is shown that a relatively weak potential can lead to a strong contraction of the polymer chain: the radius of gyration becomes much smaller compared to the size of the free cyclic chain. The pronounced decrease in the terminal relaxation time of cyclic macromolecules in the presence of a harmonic potential compared to the Rouse relaxation time leads to a lengthening of the time interval for the transition to the normal, i.
View Article and Find Full Text PDFDrug Test Anal
September 2025
Institute of Forensic Medicine, Forensic Toxicology and Chemistry, University of Bern, Bern, Switzerland.
Tetrahydrocannabidiol (H4CBD) is an emerging semisynthetic cannabinoid, which has been known since 1940. Like hexahydrocannabinol (HHC), it is easily obtained by hydrogenation of available phytocannabinoids, in the case of H4CBD by hydrogenation of cannabidiol (CBD). H4CBD shows a weak affinity for the CB receptor, but it is unclear if H4CBD shows psychoactive properties, as reports from users are divided.
View Article and Find Full Text PDFLancet
August 2025
Université de Lorraine, Inserm CIC 1433, CHRU, Nancy, France.
Background: Vericiguat is indicated to reduce the risk of cardiovascular death and hospitalisation for heart failure in patients with heart failure and reduced ejection fraction (HFrEF) following a recent worsening event. The aim of the VICTOR trial was to assess the effect of vericiguat in patients with HFrEF without recent heart failure worsening.
Methods: In this double-blind, placebo-controlled, phase 3 trial, conducted at 482 sites across 36 countries, patients aged 18 years or older with HFrEF (left ventricular ejection fraction of ≤40%) without heart failure hospitalisation within 6 months or outpatient intravenous diuretic use within 3 months before randomisation were randomly assigned (1:1) using an intervention randomisation system with interactive response technology to oral vericiguat (target 10 mg dose) or matching placebo.
Lancet
August 2025
Canadian VIGOUR Centre, University of Alberta, Edmonton, AB, Canada.
Background: Following completion of the VICTORIA trial, vericiguat was approved for the treatment of worsening heart failure with reduced ejection fraction (HFrEF) and received a class IIb recommendation in European and North American guidelines. The subsequent VICTOR trial evaluated the use of vericiguat in patients with HFrEF and no recent worsening. We aimed to assess the effect of vericiguat on clinical endpoints through pooled analyses of patient-level data from the VICTORIA and VICTOR trials.
View Article and Find Full Text PDFChem
August 2025
Department of Chemistry, The University of Chicago, Chicago, IL 60637, USA.
Ring-contraction reactions are valuable transformations to access harder-to-synthesize smaller-sized rings from more available larger-sized precursors. Herein, we report an unprecedented lactam downsizing strategy by taking advantage of removable directing groups (DGs) and Rh-catalyzed C-C activation. An efficient method for DG installation to common lactam substrates is developed by employing silylated amines and Ti catalysts, and the resulting amidine moiety can be converted back to lactams via acid-mediated hydrolysis.
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