The enthalpy and sticking probability for the dissociative adsorption of methyl iodide were measured on Pt(111) at 320 K and at low coverages (up to 0.04 ML, where 1 ML is equal to one adsorbate molecule for every surface Pt atom) using single crystal adsorption calorimetry (SCAC). At this temperature and in this coverage range, methyl iodide produces adsorbed methyl (CH(3,ad)) plus an iodine adatom (I(ad)). Combining the heat of this reaction with reported energetics for Iad gives the standard heat of formation of adsorbed methyl, ΔH(f)(0)(CH3,ad), to be −53 kJ/mol and a Pt(111)–CH3 bond energy of 197 kJ/mol. (The error bar of ±20 kJ/mol for both values is limited by the reported heat of formation of I(ad).) This is the first direct measurement of these values for any alkyl fragment on any surface.
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http://dx.doi.org/10.1021/ja400899p | DOI Listing |
Molecules
November 2024
Department of Chemistry, Faculty of Science, Sohag University, Sohag 82524, Egypt.
A series of new quinazolin-2,4-dione derivatives incorporating amide/eight-membered nitrogen-heterocycles -, in addition, acylthiourea/amide/dithiolan-4-one and/or phenylthiazolidin-4-one - and -. The starting compound was prepared by reaction of 4-(2,4-dioxo-1,4-dihydro-2-quinazolin-3-yl)-benzoyl chloride with ammonium thiocyanate and cyanoacetic acid hydrazide. The reaction of with strong electrophiles, namely, -aminophenol, -amino thiophenol, and/or -phenylene diamine, resulted in corresponding quinazolin-2,4-dione derivatives incorporating eight-membered nitrogen-heterocycles -.
View Article and Find Full Text PDFACS Cent Sci
November 2024
State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou 215123, China.
Inorg Chem
December 2024
National Co-Innovation Center for Nuclear Waste Disposal and Environmental Safety, Southwest University of Science and Technology, Mianyang 621010, China.
Nitrogen-rich small molecules are frequently doped into porous materials to enhance their iodine adsorption properties. To explore how imidazole confinement in metal-organic frameworks (MOFs) affects iodine adsorption, we obtained a UiO-66-based composite by embedding imidazole in UiO-66 pores via solid-phase adsorption (Im@UiO-66). Characterization confirmed that imidazole was successfully confined within the UiO-66 pores, with each unit of UiO-66 accommodating up to 27 imidazole molecules.
View Article and Find Full Text PDFRSC Adv
November 2024
University of Chemistry and Technology (UCT) Prague Technicka, 5 Prague 166 28 Czech Republic
Radiat Prot Dosimetry
November 2024
Department of Radioecology, Institute for Environmental Sciences, 1-7 Ienomae, Obuchi, Rokkasho, Kamikita, Aomori, 039-3212, Japan.
Japan's first commercial nuclear fuel reprocessing plant is expected to release radioiodine into the atmosphere, and orchard grass plants grown in the vicinity of this plant may absorb this radioiodine. In this study, we investigated the mechanism underlying the absorption and volatilization of iodine in the leaves of orchard grass. Our findings suggest that iodine can be transferred from the leaves of this grass to the atmosphere via two routes: direct volatilization and absorption followed by volatilization.
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