A Co(II) anilinosalen catalyst containing proton relays in the first coordination sphere has been synthesized that catalyzes the electrochemical production of hydrogen from acid in dichloromethane and acetonitrile solutions. The complex has been spectroscopically and theoretically characterized in different protonation and redox states. We show that both coordinated anilido groups of the neutral Co(II) complex can be protonated into aniline form. Protonation induces an anodic shift of more than 1 V of the reduction wave, which concomitantly becomes irreversible. Hydrogen evolution that originates from the aniline protons located in the first coordination sphere is observed upon bulk electrolysis at -1.5 V of the protonated complex in absence of external acid. Structures for intermediates in the catalytic reaction have been identified based on this data.
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http://dx.doi.org/10.1021/ic402818g | DOI Listing |
Environ Sci Technol
January 2025
State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, PR China.
Cadmium (Cd) isotopes have recently emerged as novel tracers of Cd sources and geochemical processes. Widespread clay minerals play a key role in Cd migration due to their strong adsorption capacity, but the mechanism of Cd isotope fractionation during adsorption onto clay minerals is poorly understood. Here, we experimentally investigated the adsorption mechanisms of Cd on montmorillonite (2:1) and kaolinite (1:1) by using extended X-ray absorption fine structure (EXAFS) spectroscopy.
View Article and Find Full Text PDFHealth Expect
February 2025
Community Paediatrics Research Group, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia.
Background And Objective: Migrant and refugee women, families, and their children can experience significant language, cultural, and psychosocial barriers to engage with child and family services. Integrated child and family health Hubs are increasingly promoted as a potential solution to address access barriers; however, there is scant literature on how to best implement them with migrant and refugee populations. Our aim was to explore with service providers and consumers the barriers, enablers, and experiences with Hubs and the resulting building blocks required for acceptable Hub implementation for migrant and refugee families.
View Article and Find Full Text PDFCatal Sci Technol
December 2024
Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern Freiestrasse 3 3012 Bern Switzerland
Even though α-arylation of ketones is attractive for direct C-H functionalization of organic substrates, the method largely relies on phosphine-ligated palladium complexes. Only recently, efforts have focused on developing nitrogen-based ligands as a more sustainable alternative to phosphines, with pyridine-functionalized pyridinium amidate (pyr-PYA) ,'-bidentate ligands displaying good selectivity and activity. Here, we report on a second generation set of catalyst precursors that feature a 5-membered N-heterocycle instead of a pyridine as chelating unit of the PYA ligand to provide less steric congestion for the rate-limiting transmetalation of the enolate.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States.
Controlling the rate of electron spin relaxation in paramagnetic molecules is essential for contemporary applications in molecular magnetism and quantum information science. However, the physical mechanisms of spin relaxation remain incompletely understood, and new spectroscopic observables play an important role in evaluating spin dynamics mechanisms and structure-property relationships. Here, we use cryogenic magnetic circular dichroism (MCD) spectroscopy and pulse electron paramagnetic resonance (EPR) in tandem to examine the impact of ligand field (d-d) excited states on spin relaxation rates.
View Article and Find Full Text PDFIUCrdata
December 2024
The title compound, [Fe(CHNO)(CHN)], was synthesized solvothermally. The complex exhibits a distorted octa-hedral coordination geometry. The Fe ion is located on an inversion centre.
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