The rates of chemical reactions and the dependence of their rate constants on temperature are of central importance in chemistry. Advances in the temperature-range and accuracy of kinetic measurements, principally inspired by the need to provide data for models of combustion, atmospheric, and astrophysical chemistry, show up the inadequacy of the venerable Arrhenius equation--at least, over wide ranges of temperature. This critical review will address the question of how to reach an understanding of the factors that control the rates of 'non-Arrhenius' reactions. It makes use of a number of recent kinetic measurements and shows how developments in advanced forms of transition state theory provide satisfactory explanations of complex kinetic behaviour (72 references).
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http://dx.doi.org/10.1039/b704257b | DOI Listing |
J Neurol
January 2025
Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway.
Background: Impaired impulse control is often seen in Parkinson's disease (PD) patients using dopamine agonists.
Methods: We performed a therapeutic drug monitoring study of 100 PD patients using ropinirole or pramipexole extended release. Three blood samples were collected on the same day.
Absolute line strength measurements of hydroperoxyl (HO2) radical in the OO-stretching (ν3) fundamental band have been performed by means of mid-infrared time-resolved dual-comb spectroscopy. By employing two sets of dual-comb spectrometers, high-resolution time-resolved spectra of HO2 and HCl, formed in the photolysis reaction system of Cl2/CH3OH/O2, could be, respectively, measured near 1123 and 3059 cm-1. With kinetic simulations, spectral analysis of both HO2 and HCl, as well as the accurate line strength of the HCl R(9) transition at 3059.
View Article and Find Full Text PDFSmall Methods
January 2025
Institute of Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, Zürich, 8093, Switzerland.
In situ monitoring is essential for catalytic process design, offering real-time insights into active structures and reactive intermediates. Electron paramagnetic resonance (EPR) spectroscopy excels at probing geometric and electronic properties of paramagnetic species during reactions. Yet, state-of-the-art liquid-phase EPR methods, like flat cells, require custom resonators, consume large amounts of reagents, and are unsuited for tracking initial kinetics or use with solid catalysts.
View Article and Find Full Text PDFHeliyon
January 2025
Functional Omics and Bioprocess Development Laboratory, Institute of Biological Sciences, Faculty of Science, Universiti Malaya, Kuala Lumpur, 50603, Malaysia.
Eutrophication and hypereutrophication in lakes foster harmful blue-green algal blooms, which pose a significant threat to the ecological health of freshwater reservoirs. This study investigated the effectiveness of the bio-flocculation approach using the fungus strain BGF4A1 to remove these harmful blooms, specifically targeting cyanobacterial species like PCC-7914. Key flocculation parameters, cyanobacterial concentrations, adsorption kinetics, and pellet morphology were explored in this research.
View Article and Find Full Text PDFJ Chem Eng Data
January 2025
Institute of Physical Chemistry, Technical University Darmstadt, Peter-Grünberg-Straße 8, Darmstadt D-64287, Germany.
The thermal behavior of -octanol and related ether alcohols has been studied by differential scanning calorimetry (DSC). The melting point, heat of fusion, and isobaric heat capacities of -octanol obtained from the DSC measurements are in good agreement with literature values. The ether alcohols display kinetic barriers for forming a solid phase during cooldown.
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