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Radiochemistry for Preclinical Imaging Studies
Published in George C. Kagadis, Nancy L. Ford, Dimitrios N. Karnabatidis, George K. Loudos, Handbook of Small Animal Imaging, 2018
There are numerous carbon-11-labeled building blocks and labeling reagents that are accessible by using fast and efficient organic chemistry as well as sophisticated automation approaches. An overview of this rapidly growing field is shown in Figure 16.8 (Welch and Redvanly 2003; Allard et al. 2008; Miller et al. 2008). [11C]CO2 usually requires “wet” reactions with organometallic agents. This comes with a significant risk of reduced specific radioactivity by introducing carrier carbon dioxide with a contaminated reagent. [11C]CH4 may often be converted into a secondary labeling agent in a gas phase reaction (e.g., halogenation) without major possibility of introducing carrier. The recent trend is to use [11C]CH4 as the primary irradiation product because of its potential to deliver higher specific radioactivity and its scope for simple gas phase production of secondary labeling agents. The main focus for preclinical PET radiochemistry would be on reactive intermediates that quickly transfer 11C from the gaseous starting materials into molecules of biological interest. Here, [11C]iodomethane can be regarded as the most important building block. This versatile molecule is readily accessible to PET centers by a number of commercial platforms (Miller et al. 2008). [11C] Iodomethane can be introduced into a wide variety of substrates by using alkylation reactions with acidic nitrogen, oxygen, or sulfur functional groups.
Methyl Iodide
Published in Pradyot Patnaik, Handbook of Environmental Analysis, 2017
Synonym: iodomethane; formula CH3I; MW 142.94; CAS [74-88-4]; used as a methylating agent and in microscopy; colorless liquid, turns yellow or brown on exposure to light or moisture; boils at 42.5°C; vapor pressure 375 torr at 20°C; freezes at −66.5°C; decomposes at 270°C; density 2.28 g/mL; low solubility in water (2%); soluble in alcohol and ether; toxic and carcinogenic.
Revolatilization of iodine by bubbly flow in the suppression pool during an accident
Published in Journal of Nuclear Science and Technology, 2022
Kotaro Nanjo, Jun Ishikawa, Tomoyuki Sugiyama, Marco Pellegrini, Koji Okamoto
The liquid-phase reactions included in the KICHE code include water radiolysis and inorganic and organic reactions associated with the production of I2 and organic iodine [7]. When CsI enters the liquid phase, it dissociates, and iodine takes the form of iodide ions (I−). The dose rate in the suppression pool, which can affect water radiolysis and iodine chemistry, is calculated from the amount of FPs retained in the suppression pool, assuming that all the emitted gamma and beta rays are absorbed in the liquid phase. This rate is assumed to be approximately 3 kGy/h at a maximum after core melt starts [25]. Iodine ions are oxidized to I2 under certain conditions, and some of these I2 ions can be transformed to organic iodine by organic impurities. Typical organic impurities are caused by the elution of organic solvents from the containment paint. Since both I2 and organic iodine are volatile, they are transported from the liquid phase to the gas phase [26]. In this study, organic iodine was defined separately as high-volatility organic iodine (HVRI), represented by iodomethane, and low-volatility organic iodine (LVRI), represented by iodoacetic acid.
Aqueous Biphasic Systems Using Chiral Ionic Liquids for the Enantioseparation of Mandelic Acid Enantiomers
Published in Solvent Extraction and Ion Exchange, 2018
Francisca A. e Silva, Mariam Kholany, Tânia E. Sintra, Magda Caban, Piotr Stepnowski, Sónia P. M. Ventura, João A. P. Coutinho
The six CILs here used were synthesized in our laboratory according to well-established protocols.[46] Briefly, an alkylation reaction between dimethyl sulfate and quinine yielding [C1Qui][C1SO4] was performed, L-valine-based CILs were obtained in a three step synthesis entailing reduction of L-valine, Eschweiler-Clark reaction and N-alkylation and L-proline-based CILs were synthesized by alkylation reactions between L-proline and iodomethane, bromoethane, or dimethyl sulfate affording [C1C1C1Pro]I, [C2C2C2Pro]Br or [C1C1C1Pro][C1SO4], respectively. Relevant features of CILs, namely melting temperature (Tm, °C), decomposition temperature (Td, °C) and specific rotations () can be consulted in Supplemental Material, Table S1.[46]
Synthesis and application of cationic fluorocarbon surfactants
Published in Journal of Dispersion Science and Technology, 2023
Saipeng Zhang, Mingxin Zhang, Xingjiang Liu, Liuhe Wei
Isophorone diisocyanate, 4,4′-diphenyl methane diisocyanate, 4,4′ -dicyclohexyl methane diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, 1H,1H,2H,2H-tridecafluoro-1-octanol, 2-(dimethylamino)ethanol, iodomethane, dibutyltin laurate, toluene, tetrahydrofuran, dichloromethane, petroleum ether, deionized water are available provided by Shanghai Exploration Platform. Toluene and tetrahydrofuran need to be used after redistillation, other reagents and solvents are used as they are.