F:Flammable;
74-88-4Relevant articles and documents
Estimate of the iodine-iodine two-center three-electron bond energy in [CH3-I-I-CH3]+
Livant, Peter,Illies, Andreas
, p. 1510 - 1513 (1991)
The gas-phase ion-molecule association reaction CH3I+ + CH3I ? [CH3-I-I-CH3]+ in various bath gases was studied at 503 K. The iodine-iodine bond in the association product is an example of a two-center three-electron (2c-3e) or a 2σ/1σ* bond. The bond energy was estimated from ΔG° of reaction, which was in turn determined from equilibrium experiments. Assuming a value for ΔS° of reaction of -20 to -25 cal/(mol K), a bond strength of 23-26 kcal/mol is estimated. This is the first experimental gas-phase binding energy estimate for a 2c-3e bond in an organic molecule involving an iodine-iodine interaction and one of only a few experimental studies of well-characterized gas-phase 2c-3e bonding interactions between heteroatoms in organic molecules. A study of the ion-molecule reactions occurring at low ionizing energies leading to (CH3)2I+, [C2H3I2]+, and [CH3-I-I-CH3]+ is discussed.
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Henry
, p. 348 (1890)
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Rate Constants for Oxidation Reactions by Radical Cations from Methyl Iodide
Mohan, Hari,Asmus, Klaus-Dieter
, p. 118 - 122 (1988)
Radical cations from methyl iodide, CH3I.+, and are shown to be excellent oxidants with a one-electron redox potential presumably >/= +2 V.Absolute rate constants in the order of 1E9 M-1s-1 have been determined for their reactions with various organic sulfides, disulfides thiols, phenothiazines, and inorganic metal and halide ions.A similarly high reactivity has also been found for the hydroxyl radical adduct to methyl iodide, CH3I(OH)..The results are discussed in view of electronic and steric structure of these oxidizing radical species and the substrates to be oxidized.
The Decomposition of Acidic Karl Fischer Reagent in Methanol
Fischer, Wolfgang,Beckenkamp, Konrad
, p. 58 - 62 (1998)
The reaction between sulfur dioxide and iodine in methanol is started by traces of water in the solvent. Hydrogen iodide is formed and reacts with methanol to produce more water until all iodine is used up. An addition compound between iodine and hydrogen sulfite was found as an intermediate and characterized by Raman spectroscopy. Elementary sulfur is formed in a second reaction.
Martin,Sutton
, p. 812 (1952)
Thermal behaviour of a modified encapsulation agent: Heptakis-6-iodo-6-deoxy-beta-cyclodextrin
Fulia, Adriana,Vlase, Gabriela,oica, Codrua,Bercean, Vasile,Vlase, Titus,Ledei, Ionu
, p. 961 - 966 (2014)
Thermal behaviour of heptakis-6-iodo-6-deoxy-beta-cyclodextrin (HIDBCD) under inert and oxidative conditions was investigated by TG/DTG/DTA, FTIR, and using the hyphenate technique TG-FTIR. Due to the fact that thermal behaviour of HIDBCD was not studied before, we set our goal in the investigation of thermal degradation process in a dynamic air atmosphere vs. nitrogen atmosphere at a heating rate of 10 °C min-1, up to 500 °C, respectively, 600 °C. It was found that the degradation process in air occurs in a single step, with a total mass loss of 99.9 %. The results of TG/DTG/DTA-FTIR indicated that the thermal behaviour of this cyclodextrin can be divided into three stages and more information was provided about the reaction sequences and the relevant products of reaction.
Photoinitiation of gas-phase S(N)2 reactions through the evans-polanyi excited state surface [17]
Dessent,Johnson
, p. 5067 - 5068 (1997)
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Methyl sulfates as methoxy isotopic reference materials for δ13C and δ2H measurements
Greule, Markus,Keppler, Frank,Moossen, Heiko,Geilmann, Heike,Brand, Willi A.
, p. 343 - 350 (2019)
Rationale: Stable hydrogen and carbon isotope ratios of methoxy groups (OCH3) of plant organic matter have many potential applications in biogeochemical, atmospheric and food research. So far, most of the analyses of plant methoxy groups by isotope ratio mass spectrometry have employed liquid iodomethane (CH3I) as the reference material to normalise stable isotope measurements of these moieties to isotope–δ scales. However, comparisons of measurements of stable hydrogen and carbon isotopes of plant methoxy groups are still hindered by the lack of suitable reference materials. Methods: We have investigated two methyl sulfate salts (HUBG1 and HUBG2), which exclusively contain carbon and hydrogen from one methoxy group, for their suitability as methoxy reference materials. Firstly, the stable hydrogen and carbon isotope values of the bulk compounds were calibrated against international reference substances by high-temperature conversion- and elemental analyser isotope ratio mass spectrometry (HTC- and EA-IRMS). In a second step these values were compared with values obtained by measurements using gas chromatography/isotope ratio mass spectrometry (GC/IRMS) where prior to analysis the methoxy groups were converted into gaseous iodomethane. Results: The 2H- and 13C isotopic abundances of HUBG1 measured by HTC- and EA-IRMS and expressed as δ-values on the usual international scales are ?144.5 ± 1.2 mUr (n = 30) and ?50.31 ± 0.16 mUr (n = 14), respectively. For HUBG2 we obtained ?102.0 ± 1.3 mUr (n = 32) and +1.60 ± 0.12 mUr (n = 16). Furthermore, the values obtained by GC/IRMS were in good agreement with the HTC- and EA-IRMS values. Conclusions: We suggest that both methyl sulfates are suitable reference materials for normalisation of isotope measurements of carbon of plant methoxy groups to isotope–δ scales and for inter-laboratory calibration. For stable hydrogen isotope measurements, we suggest that in addition to HUBG1 and HUBG2 additional reference materials are required to cover the full range of plant methoxy groups reported so far.
Electronically Excited States of the CH3I2+ Ion
Griffiths, William J.,Harris, Frank M.,Parry, David E.
, p. 2801 - 2804 (1990)
A double-charge-transfer spectroscopy study has provided evidence for the existence of four low-lying electronic states of the CH3I2+ ion, the double-ionization energies to which are 27.0 +/- 0.3, 29.6 +/- 0.3, 31.3 +/- 0.5 and 36.5 +/- 0.5 eV.Three of these energies agree, within experimental error, with those determined previously in a dissociative double photoionization study of CH3I.The present investigation reveals for the first time the state at 29.6 eV.The value of the double-ionization energy to the ground triplet state, calculated in the present investigation using the single-determinant Hartree-Fock approximation to the many-electron wavefunction with corrections of second-order Moeller-Plesset perturbation theory for correlation effects, is 25.80 eV, somewhat lower than the measured value of 27.0 eV.
Nichol,Ubbelohde
, p. 415,419 (1952)
Functionalization of RhIII-Me Bonds: Use of capping Arene Ligands to Facilitate Me-X Reductive Elimination
Gu, Shunyan,Chen, Junqi,Musgrave, Charles B.,Gehman, Zo? M.,Habgood, Laurel G.,Jia, Xiaofan,Dickie, Diane A.,Goddard, William A.,Gunnoe, T. Brent
, p. 1889 - 1906 (2021/05/29)
We show how to improve the yield of MeX from CH4 activation catalysts from 12% to 90% through the use of capping arene ligands. Four (FP)RhIII(Me)(TFA)2 {FP = capping arene ligands, including 8,8′-(1,2-phenylene)diquinoline (6-FP), 8,8′-(1,2-naphthalene)diquinoline (6-NPFP), 1,2-bis(N-7-azaindolyl)benzene (5-FP), and 1,2-bis(N-7-azaindolyl)naphthalene (5-NPFP)} complexes. These complexes and (dpe)RhIII(Me)(TFA)2 (dpe = 1,2-di-2-pyridylethane) were synthesized and tested for their performance in reductive elimination of MeX (X = TFA or halide). The FP ligands were used with the goal of blocking a coordination site to destabilize the RhIII complexes and facilitate MeX reductive elimination. On the basis of single-crystal X-ray diffraction studies, the 6-FP and 6-NPFP ligated Rh complexes have Rh-arene distances shorter than those of the 5-FP and 5-NPFP Rh complexes; thus, it is expected that the Rh-arene interactions are weaker for the 5-FP complexes than for the 6-FP complexes. Consistent with our hypothesis, the 5-FP and 5-NPFP RhIII complexes demonstrate improved performance (from 12% to ～60% yield) in the reductive elimination of MeX. The reductive elimination of MeX from (FP)RhIII(Me)(TFA)2 can be further improved by the use of chemical oxidants. For example, the addition of 2 equiv of AgOTf leads to 87(2)% yield of MeTFA and can be achieved in CD3CN at 90 °C using (5-FP)Rh(Me)(TFA)2.
Modular Dual-Tasked C-H Methylation via the Catellani Strategy
Gao, Qianwen,Shang, Yong,Song, Fuzhen,Ye, Jinxiang,Liu, Ze-Shui,Li, Lisha,Cheng, Hong-Gang,Zhou, Qianghui
supporting information, p. 15986 - 15993 (2019/10/11)
We report a dual-tasked methylation that is based on cooperative palladium/norbornene catalysis. Readily available (hetero)aryl halides (39 iodides and 4 bromides) and inexpensive MeOTs or trimethylphosphate are utilized as the substrates and methylating reagent, respectively. Six types of "ipso" terminations can modularly couple with this "ortho" C-H methylation to constitute a versatile methylation toolbox for preparing diversified methylated arenes. This toolbox features inexpensive methyl sources, excellent functional-group tolerance, simple reaction procedures, and scalability. Importantly, it can be uneventfully extended to isotope-labeled methylation by switching to the corresponding reagents CD3OTs or 13CH3OTs. Moreover, this toolbox can be applied to late-stage modification of biorelevant substrates with complete stereoretention. We believe these salient and practical features of our dual-tasked methylation toolbox will be welcomed by academic and industrial researchers.
