Reaction Of Methyl Iodide Research Articles

Simultaneous tracking of ultrafast surface and gas-phase dynamics in solid-gas interfacial reactions.

Real-time detection of intermediate species and final products at the surface and near-surface in interfacial solid-gas reactions is critical for an accurate understanding of heterogeneous reaction mechanisms. In this article, an experimental method that can simultaneously monitor the ultrafast dynamics at the surface and above the surface in photoinduced heterogeneous reactions is presented. This method relies on a combination of mass spectrometry and femtosecond pump-probe spectroscopy. As a model system, the photoinduced reaction of methyl iodide on and above a cerium oxide surface is investigated. The species that are simultaneously detected from the surface and gas-phase present distinct features in the mass spectra, such as a sharp peak followed by an adjacent broad shoulder. The sharp peak is attributed to the species detected from the surface, while the broad shoulder is due to the detection of gas-phase species above the surface, as confirmed by multiple experiments. By monitoring the evolution of the sharp peak and broad shoulder as a function of the pump-probe time delay, transient signals are obtained that describe the ultrafast photoinduced reaction dynamics of methyl iodide on the surface and in the gas-phase. Finally, SimION simulations are performed to confirm the origin of the ions produced on the surface and in the gas-phase.

A Raman Spectroscopic Study of Radiation-Grafted Anion-Exchange Membranes Containing Different Anions

Anion exchange membranes (AEM) are being developed for use in a variety of electrochemical energy systems, such as alkaline membrane fuel cells, AEM-based electrolysers, reverse electrodialysis (RED), and redox flow batteries (RFB). The AEMs used will contain a variety of anions, depending on the application. For fuel cells and electrolysers (H2 generating or CO2 conversion), then alkaline anions such as OH-, CO3 2-, and HCO3 - are important. For RED cells and RFBs, non-alkali anions such as Cl-, HSO4 -, and SO4 2- are more relevant. If an AEM is synthesised using a methyl iodide reaction, then monitoring the ion-exchange of the resulting "as-synthesised" I- forms to other forms, such as Cl-, is important as it is well known that it can be difficult to completely ion-exchange soft anions such as I- out of AEMs (particularly those containing aromatic cationic groups).This presentation will highlight some initial results obtained from an on-going Raman spectroscopic study of radiation-grafted AEMs (RG-AEM). This study was initiated to see if Raman spectro-microscopy can be used to identify the anion form of a RG-AEM by looking at the shifts and intensity changes of Raman peaks as a function of anion. The RG-AEMs will be made from either the grafting of vinylbenzyl chloride onto ETFE (followed by reaction with amines such as trimethylamine, imidazole and pyridine) or the grafting of alternative monomers such as vinylpyridine onto ETFE (followed by reaction with methyl iodide).The below Figure shows Raman spectra (Renishaw inVia Raman microscope: 785 nm laser, 1800 lines mm-1 grating, and x20 objective giving a Airy spot diameter of ca. 3 μm) of a RG-AEM made from the grafting of vinylpyridine onto ETFE films (with a final methyl iodide reaction) in both the I- and Cl- forms (three spectra each):. Figure 1

Carbon‐iodide bond activation by cyclometalated Pt (II) complexes bearing tricyclohexylphosphine ligand: A comparative kinetic study and theoretical elucidation

Cyclometalated Pt (II) complexes [PtMe(C^N)(L)], in which C^N = deprotonated 2,2′‐bipyridine N‐oxide (Obpy), 1, deprotonated 2‐phenylpyridine (ppy), 2, deprotonated benzo [h] quinolone (bzq), 3, and L = tricyclohexylphosphine (PCy3) were prepared and fully characterized. By treatment of 1–3 with excess MeI, the thermodynamically favored Pt (IV) complexes cis‐[PtMe2I(C^N)(PCy3)] (C^N = Obpy, 1a; ppy, 2a; and bzq, 3a) were obtained as the major products in which the incoming methyl and iodine groups adopted cis positions relative to each other. All the complexes were characterized by means of NMR spectroscopy while the absolute configuration of 1a was further determined by X‐ray crystal structure analysis. The reaction of methyl iodide with 1–3 were kinetically explored using UV–vis spectroscopy. On the basis of the kinetic data together with the time‐resolved NMR investigation, it was established that the oxidative addition reaction occurred through the classical SN2 attack of Pt (II) center on the MeI reagent. Moreover, comparative kinetic studies demonstrated that the electronic and steric nature of either the cyclometalating ligands or the phosphine ligand influence the rate of reaction. Surprisingly, by extending the oxidative addition reaction time, very stable iodine‐bridged Pt (IV)‐Pt (IV) complexes [Pt2Me4(C^N)2(μ‐I)2] (C^N = Obpy, 1b; ppy, 2b; and bzq, 3b) were obtained and isolated. In order to find a reasonable explanation for the observation, a DFT (density functional theory) computational analysis was undertaken and it was found that the results were consistent with the experimental findings.

Substituted manganese phthalocyanines as bleach catalysts: synthesis, characterization and the investigation of de-aggregation behavior with LiCl in solutions

This study reported the oxidative degradation of morin dye with hydrogen peroxide catalyzed by manganese phthalocyanines as low temperature bleaching catalysts for laundry applications. A novel series of manganese phthalocyanines (MnPcs) have been synthesized starting with tetrakis[4-(1,3-dioxolan-2-yl)phenoxy)]phthalocyaninatomanganese(III) (2) prepared by the cyclotetramerization of 4-[4-(1,3-dioxolan-2-yl)phenoxy]-phthalonitrile (1). De-protection of acetal groups of 2 to the aldehyde group in an acetic acid/FeCl3 system yielded the tetrakis(4-formylphenoxy)phthalocyaninatomanganese(III) (3). The condensation of 3 with 3-(dimethylamino)-1-propylamine gave Schiff base-substituted Mn(III)Pc 4. Finally, quaternization of the dimethylamino functional groups with the reaction of methyl iodide produced cationic manganese(III) phthalocyanine 5 which was soluble in both DMSO and water. These new MnPcs were characterized by the combination of spectroscopic methods (FT-IR, UV–Vis and mass spectroscopy). The effects of structural variables of the prepared compounds (2–5) on their dissolution in the solvent system LiCl/DMAc-DMF-DMSO and THF were also investigated. Degradation of morin at 25 and 40 °C in the presence of catalysts (2–5)/H2O2 combination in basic medium was examined by online spectrophotometric method, and the bleaching activities of the prepared compounds have been evaluated comparatively. It was found that the prepared catalysts have more effective bleaching performance at 25 °C than tetraacetylethylenediamine (TAED) which is a bleach activator commercially used in powder detergent formulations.

Synthesis of Oleanolic Acid Analogues and Their Cytotoxic Effects on 3T3 Cell Line.

Oleanolic acid (OA) is a known natural compound with many important biological activities. Thirteen oleanolic acid derivatives linked at C-3 and C-28 were synthesized and their structures were confirmed by 1H- and 13C NMR and mass spectral analyses. Among them, compounds 4, 6, 8-10, 12, 13 were synthesized for the first time. They were evaluated for their cytotoxic activity. They showed proliferative effect at low concentrations while cytotoxic effect was observed at high concentrations in a dose dependent manner. We have first synthesized compounds 1 and 2 from the reaction of methyl iodide and OA. Compound 1 was reduced with LiAlH4 to give compound 3, and compound 2 gave compound 9 with MOMBr as a new compound. The compound 10 was then obtained from the reduction of compound 9 with LiAlH4 as a new oleanolic acid derivative. A diol derivative 11 was synthesized from OA and LiAlH4 at the room temperature. Compound 4 was obtained from the reaction of compound 3 with CBr4 as a new analogue of OA, and the reduction of compound 4 afforded compound 5 as a known product. In addition, we synthesized compounds 6-8 from compound 3 using MsCl, MeI and p-nitrobenzoyl chloride, respectively, in good yields. Compounds 6 and 8 are new analogues of OA. The new compounds 12 and 13 were also synthesized starting from OA using with MOMBr and TBDMSiCl as the reagents. The all synthesized compounds were purified by using column chromatography and/or crystallization. In the present study, thirteen OA derivatives linked at C-28 and (or) C-3 were synthesized and evaluated for their cytotoxic activity on 3T3 cell lines which are the standard fibroblast cell lines, derived from Swiss albino mouse embryo tissue. 3T3 cell viability was observed at low concentrations of the tested triterpenoids while they displayed anti-proliferative effect at higher concentrations. Oleanolic acid 28-methyl ester (2) showed fairly different behavior from all the other compounds tested and found to be the least cytotoxic compound. However, at 200 µM concentration, it exhibited the same cytotoxicity with compounds 3, 9 and 10 around 58-59%. Among the tested 13 compounds, 7 exhibited the most drastic decline for the viability from 12,5 µM to 25 µM concentration. Compound 6 displayed the most cytotoxic effect, almost in all concentrations, particularly at 6.25 and 25 µM concentrations while the highest cytotoxic effect at 50 µM was observed for compound 11 among all the tested triterpenoids. As a result, all the tested OA derivatives showed proliferative effect at 1,56 µM although no proliferative effect was observed for OA. Moreover, OA exhibited higher cytotoxic effect than its derivatives, particularly at higher concentrations (50, 100, 200 µM) with an exception for compound 11. Because, the latter showed highest proliferative effect at lowest concentration, and highest anti-proliferative effect at highest concentration which surpassed all the OA derivatives.

Transalkylation of alkyl aryl sulfides with alkylating agents

The reaction of methyl iodide with tert-butylphenylsulfide in DMF leads to a transalkylation that produces methylphenylsulfide. This transalkylation reaction was further studied by 1H NMR spectroscopy. The polarity of the solvent, the electron density on the sulfur atom, and the strength of the alkylating agent (MeI, EtI, BuI, dimethyl sulfate, or dimethyl carbonate) played important roles in the reaction. The suggested mechanism of the reaction involves the formation of a dialkyl aryl sulfonium salt that subsequently eliminates the radical. This mechanism was supported by the observation of higher conversion rates for compounds with more branched alkyl groups on the sulfur atom, which may lead to the formation of more stable radicals.

Specific reactivity of 2,4,6-tri-tert-butylanilide anions and its application to benzylation reagent

The reaction of methyl iodide with an anilide anion prepared from 2,4,6-tri-tert-butylanilide and NaH in CH3CN gave N-methyl anilide (N-alkylation product) as a major product, while in the reaction of benzyl bromide with the anilide anion in DMF, O-benzyl imidate (O-alkylation product) was obtained with almost complete selectivity. The treatment of O-benzyl imidate with alcohols and carboxylic acids in the presence of trifluoromethane sulfonic acid gave benzyl ethers and benzyl esters, respectively.

Preparation of Methylated Products of A-type Procyanidin Trimers in Cinnamon Bark and Their Protective Effects on Pancreatic β-Cell.

Polyphenols are partial metabolized to methylated conjugations in vivo, and then could modify bioavailability and bioactivity related to the uptake of parent compounds. Our previous studies have found that the antidiabetic effects of cinnamon barks are mainly related to polyphenol components, particularly A-type procyanidin trimer cinnamtannin-1 (CT1). It is necessary to understand the antidiabetic activity of methylations of CT1, nevertheless, sufficient amounts of methylated CT1 are difficult to obtain from metabolites in vivo. In this study, O-methyl derivatives of CT1 were prepared through one-pot methyl iodide reaction and isolation via column chromatography and RP-HPLC semipreparation. The structures of O-methyl substituents were determined through NMR (Nuclear Magnetic Resonance) and HPLC-ESI-MS (High-performance liquid chromatography-electrospray ionization-mass spectrometry). Five purified O-methyl substituents and 2 isomers of CT1 were obtained. Their protective effects on a palmitic acid-induced pancreatic β-cell apoptosis model were then evaluated. Results showed that the protective effects on pancreatic β-cell of O-methyl substituents were weaker than those of CT1. The results suggested that the methylation of catechol groups could be a relevant factor contributing to the decline of protective effects on pancreatic β-cell of CT1 via obstructing quinone intermediate formation and affecting antioxidant abilities. The antidiabetic effects of O-methyl derivatives of CT1 should be further determined by other antidiabetic models.

Synthesis, characterization, crystal structure, solvatochromism, fluorescence and electrochemical studies of new organometallic platinum complexes, kinetic investigation of oxidative addition reaction

A new organoplatinum(II) complex containing 2,2′-biquinoline ligand (biq) was synthesized by the reaction of [Pt(p-MeC6H4)2(SMe2)2] with 2,2′-biquinoline in a 1:1 molar ratio. In this complex the ligand was coordinated to metal via the chelating nitrogen donor atoms. Also, platinum(IV) complex was obtained by the oxidative addition reaction of the methyl iodide with the platinum(II) complex in acetone. The platinum complexes have been found to possess 1:1 metal to ligand stoichiometry and the molar conductance data revealed that the metal complexes were non-electrolytes. The platinum(II) and platinum(IV) complexes exhibited square planar and octahedral coordination geometry, respectively. The emission spectra of the platinum(II) and platinum(IV) complexes were studied in dichloromethane. Furthermore, electrochemical properties of the metal complexes were investigated in dimethylformamide (DMF) solvent at 150 mV s−1 scan rate. The ligand and metal complexes showed both reversible and irreversible processes at this scan rate. The complexes have been characterized by IR, 1H NMR, UV/Vis, elemental analysis and conductometry. The crystal structure of the platinum(II) complex containing 2,2′-biquinoline has been determined by single crystal X-ray diffraction. Moreover, kinetic studies of the oxidative addition reaction of methyl iodide with the platinum(II) complex in different temperatures were investigated. It was indicated that the reaction occurred by the SN2 mechanism. The rate of reaction in two different solvents was compared and the activation parameters were determined.

Synthesis and Characterization of Methyl(perfluoroalkyl)Tellurium(II) Compounds, MeTeRf (Rf = CF3, C2F5), the Corresponding Tellurium(IV) Dihalides, MeTe(Rf)X2 (X = F, Cl, Br, I), and Bis(trifluoroacetates), MeTe(Rf)(OCOCF3)2

Abstract MeTeRf (Rf = CF3, C2F5) can easily be prepared via the reactions of methyl iodide and the corresponding tetramethylammonium perfluoroalkyltellurates(0), [NMe4]TeRf (Rf = CF3, C2F5). Both compounds are easily oxidized by xenon difluoride and the heavier halogens to yield the corresponding dihalides, MeTe(Rf)X2 (X = F, Cl, Br, I) and by ArI(OCOCF3)2 to give the corresponding trifluoroacetates, MeTe(Rf)(OCOCF3)2. All compounds are characterized byspectroscopic means. The molecular structures of MeTe(Rf)F2,MeTe(Rf)Cl2, MeTe(Rf)Br2, and of 4‐MeC6H4I(OCOCF3)2 were elucidated by XRD methods.

Methyl iodide oxidative addition to [Rh(acac)(CO)(PPh3)]: an experimental and theoretical study of the stereochemistry of the products and the reaction mechanism

Density functional theory was used to investigate the oxidative addition and subsequent carbonyl insertion and deinsertion steps of the reaction of methyl iodide to a rhodium(I) acetylacetonato complex of the formula [Rh(acac)(CO)(PPh(3))] (Hacac = acetylacetone). This process has been studied experimentally for many rhodium β-diketonato complexes, but, to the best of our knowledge, this is the first systematic computational study of the complete reaction sequence. Experimental (1)H techniques complement the theoretical results on the stereochemistry of the reaction intermediates and products. (1)H NMR also revealed the existence of a second rhodium(III)-acyl product, which has not been previously observed in this reaction. The calculated Gibbs free energy of activation of the oxidative addition reaction is 71 kJ mol(-1), which is in agreement with the experimental value of 82(1) kJ mol(-1). The DFT-calculated oxidative addition corresponds to an associative S(N)2 nucleophilic attack by the rhodium metal centre on the methyl iodide, which is in agreement with calculated and experimental (in brackets) activation parameters of the reaction, 27 (38.8) kJ mol(-1) for ΔH((≠)) and -147 (-146) J K(-1) mol(-1) for ΔS((≠)).

Synthesis and biodistribution of [11C]SN‐38

AbstractSN‐38 (7‐ethyl‐10‐hydroxy camptothecin) is a topoisomerase I inhibitor that is the active chemotherapeutic agent of irinotecan, indicated for colon cancer. Because the rate of response to irinotecan treatment is low, it is of interest to have a prognostic indicator to identify and more selectively treat those who are likely to respond to treatment. We have therefore prepared SN‐38 labeled with carbon‐11. SN‐38 was prepared by radical oxidation of 3‐[11C]propionaldehyde and subsequent radical addition of the ethyl fragment to 10‐hydroxycamptothecin. Labeled propionaldehyde was prepared by reaction of methyl iodide with 2‐lithiomethyl‐1,3‐dioxolane. Overall chemical yield was 34% from carbon dioxide. The murine biodistribution and radiation dosimetry of [11C]SN‐38 was measured by PET scanning in preparation for initial human studies. Biodistribution was fairly uniform except for hepatobiliary and urinary excretion. Copyright © 2010 John Wiley & Sons, Ltd.

Optimization of cellulose acrylate and grafted 4-vinylpyridine and 1-vinylimidazole synthesis

Optimization of cellulose acrylate synthesis by reaction with sodium cellulosate and acryloyl chloride was carried out. Optimal conditions for conducting the synthesis reaction of cellulose acrylate were as follows: the molar ratio of cellulose/potassium-t-butoxide/acryloyl chloride was 1:3:10 and the optimal reaction time was 10 h. On the basis of elemental analysis with optimal conditions for conducting the reaction of cellulose acrylate, the percentage of substitution of glucose units in cellulose Y = 80.7%, and the degree of substitution of cellulose acrylate DS = 2.4 was determined. The grafting reaction of acrylate vinyl monomers onto cellulose in acetonitrile with initiator azoisobutyronitrile (AIBN) in a nitrogen atmosphere was performed, by mixing for 5 h at acetonitrile boiling temperature. Radical copolymerization of synthesized cellulose acrylate and 4-vinylpyridine, 1-vinylimidazole, 1-vinyl-2-pyrrolidinone and 9-vinylcarbazole, cellulose-poly-4-vinylpyridine (Cell-PVP), cellulose-poly-1- vinylimidazole (Cell-PVIm) and cellulose-poly-1-vinyl-2-pyrrolidinone (Cell-P1V2P) and cellulose-poly-9-vinylcarbazole (Cell-P9VK) were synthesized. Acrylate cellulose and cellulose grafted copolymers were confirmed by IR spectroscopy, based on elementary analysis and the characteristics of grafted copolymers of cellulose were determined. The mass share of grafted copolymers, X, the relationship of derivative parts/cellulose vinyl group, Z, and the degree of grafting copolymers of cellulose (mass%) were determined. In reaction of methyl iodide and cellulose-poly-4-vinylpyridine (Cell-PVP) the cellulose-1-methyl-poly-4-vinylpyridine iodide (Cell-1-Me-PVPJ) was synthesized. Cellulose acrylate and grafted copolymers were obtained with better thermal, electrochemical and ion-emulation properties for bonding of noble metals Au, Pt, Pd from water solutions. The synthesis optimization of cellulose acrylate was applied as a model for the synthesis of grafted lignin copolymers and grafted tannin polymers with vinyl monomers.

Steric and Solvent Effects on the Secondary Kinetic α-Deuterium Isotope Effects in the Reaction of Methyl Iodide with Organoplatinum(II) Complexes: Application of a Second-Order Technique in Measuring the Rates of Rapid Processes

The kinetic isotope effects (KIEs), kH/kD, have been determined for reaction of CH3I/CD3I with several organoplatinum(II) complexes [PtR2(NN)], in which the bidentate NN ligand is bpy = 2,2′-bipyridine, tBu2bpy = 4,4′-bis(tert-butyl)-2,2′-bipyridine, phen = 1,10-phenanthroline, or Me2phen = 2,9-dimethyl-1,10-phenanthroline, at different temperatures and in solvents having different polarities. The values obtained for the secondary α-deuterium KIEs are close to 1 and are dependent on the solvent; values of up to 7−10% larger are obtained for the reactions in the polar solvent acetone as compared to those obtained in the nonpolar solvent benzene. The data also indicate that the steric crowding around the square-planar coordination sphere of the platinum(II) complexes with the ligand Me2phen results in higher KIEs. The reactions involving dimethylplatinum(II) complexes, [PtMe2(NN)], were fast, and a 1:1 molar ratio (of complex and reagent) technique was successfully used to measure the rate constants accurately by conventional UV−visible spectroscopy. It is shown that there are significant advantages to measuring the reaction rates under second-order condition, as compared to the usual pseudo-first-order method.

Synthesis and kinetic studies of new bipyridyl platinum(II) phenoxide complexes by phase transfer catalysis: Crystal structure of [(bipy)Pt(OC6H4-4-OMe)2

Abstract The synthesis of new platinum bipy (bipy = 2,2′-bipyridyl) complexes containing phenoxide ligands is reported, together with kinetic studies of their oxidative addition reactions with MeI to produce phenoxo platinum(IV) complexes. Complexes of the form [(bipy)Pt(OC 6 H 4 -4-X) 2 ] (X = OCH 3 , CH 3 , H, Br, Cl) are prepared by the reaction of the chloro complex [(bipy)PtCl 2 ] with substituted phenols and KOH in a two phase system of water and chloroform in the presence of benzyl triphenylphosphonium chloride. Platinum(IV) complexes are formed by oxidative addition of MeI to the platinum(II) complexes obtained. The complexes are characterized by elemental analysis, UV–Vis, IR, mass spectrometry and 1 H and 13 C NMR spectroscopy. The reaction of methyl iodide with [(bipy)Pt(OC 6 H 4 -4-OMe) 2 ] to give [(bipy)PtMe(I)(OC 6 H 4 -4-OMe) 2 ] follows the rate law rate = k 2 [(bipy)Pt(OC 6 H 4 -4-OMe) 2 ][MeI]. The values of k 2 increase with increasing polarity of the solvent, suggesting a polar transition state for the reaction.

Synthesis of 2-(3,3-dimethyl-3,4-dihydroisoquinol-1-yl)propanoic acid amides and their influence on blood coagulation

A series of new 2-(3,3-dimethyl-3,4-dihydroisoquinol-1-yl)propanoic acid amides have been synthesized using the reaction of methyliodide with 2-(3,3-dimethyl-1,2,3,4-tetrahydroisoquinolin-1-idene)ethanamides that proceeds on the β-atom of the enamine fragment to form iodides of 2-(isoquinol-1-yl)propanoic acid derivatives. Investigation of the influence of the synthesized compounds on blood coagulation showed that all of them are hemostatics. The most active compounds possess radicals such as morpholine and 2-(3,4-dimethoxyphenyl)ethylamine, are not substituted at the amide fragment, and decrease the blood coagulation time by 14-16%.

Stereochemistry of the reaction products of the oxidative addition reaction of methyl iodide to [Rh((C 4H 3S)COCHCOR)(CO)(PPh 3)]: A NMR and computational study. R = CF 3, C 6H 5, C 4H 3S

A NMR study of the reaction mixture of the square planar [Rh((C 4H 3S)COCHCOR)(CO)(PPh 3)] complex and CH 3I, where R = CF 3, C 6H 5 or C 4H 3S, revealed that two types of alkyl and one (R = CF 3) or two (R = C 6H 5 or C 4H 3S) types of acyl species exist in the system. Two isomers of each species with an unsymmetrical β-diketonato ligand were observed. 1H– 1H NOESY NMR unambiguously showed that the PPh 3 group is in the apical position in the more stable Rh III-alkyl product. Theoretical computations of the equilibrium geometry of the possible reaction products, consistent with experimental observations, revealed that the first alkyl product results from trans addition to Rh I and that the second thermodynamic alkyl product adopts an octahedral geometry with the PPh 3 group and the iodide above and below the square planar plane. Theoretical computations also revealed that the thermodynamic acyl product adopts a square-pyramidal geometry with the COCH 3 group in the apical position.

Solvation effects in oxidative addition reaction of Methyliodide to Pt(II) complex: A theoretical study with RISM–SCF method

Solvation effects in S N2-type oxidative addition of MeI to PtMe 2(NH 3) 2 was theoretically investigated with RISM–SCF, which provides both of quantum chemical and statistical mechanical information on solvation system. Though the reaction is very difficult to occur in gas phase because of the high barrier which is induced by dissociation of iodide anion from methyl group, the reaction easily occurs in nitromethane because iodide anion is stabilized by nitromethane solvent. This stabilization mainly arises from the solvation free energy of platinum center and iodide anion. The solvation structure obtained from RISM–SCF provides the reason why this reaction easily occurs in nitromethane.

Electron stimulated reactions of methyl iodide coadsorbed with amorphous solid water

The electron stimulated reactions of methyl iodide (MeI) adsorbed on and suspended within amorphous solid water (ice) were studied using a combination of postirradiation temperature programmed desorption and reflection absorption infrared spectroscopy. For MeI adsorbed on top of amorphous solid water (ice), electron beam irradiation is responsible for both structural and chemical transformations within the overlayer. Electron stimulated reactions of MeI result principally in the formation of methyl radicals and solvated iodide anions. The cross section for electron stimulated decomposition of MeI is comparable to the gas phase value and is only weakly dependent upon the local environment. For both adsorbed MeI and suspended MeI, reactions of methyl radicals within MeI clusters lead to the formation of ethane, ethyl iodide, and diiodomethane. In contrast, reactions between the products of methyl iodide and water dissociation are responsible for the formation of methanol and carbon dioxide. Methane, formed as a result of reactions between methyl radicals and either parent MeI molecules or hydrogen atoms, is also observed. The product distribution is found to depend on the film's initial chemical composition as well as the electron fluence. Results from this study highlight the similarities in the carbon-containing products formed when monohalomethanes coadsorbed with amorphous solid water are irradiated by either electrons or photons.

The course of oxidative addition reactions of haloalkynes and haloalkenes to dimethyl- and dialkynylaurate(I) anions [RAuR] −

The reactions of halo-alkynes Cl–C CH, C–lC C–Cl or PhC C–I with solutions of Li +[MeAuMe] − in diethylether containing Ph 3P do not give the expected oxidative addition products Me 2(RC C)Au(PPh 3) with R = H, Cl, Ph. A mixture of other complexes is obtained instead which are generated in secondary reactions involving reductive elimination of ethane and/or dialkyne. However, addition of the halo-alkene H(Cl)C CCl 2 to the same substrate solution affords trans-Me 2[ trans-H(Cl)C C(Cl)]Au(PPh 3) in good yield. Its molecular structure with pseudo- C s symmetry has been determined by the solution NMR spectra and a single-crystal X-ray diffraction study. The reaction of methyl iodide with solutions of Li +[RC CAuC CR] − in diethylether containing PPh 3 give the quaternary salts Ph 3PMe + [RC CAuC CR] − as the main products and only small amounts of cis-Me 2(RC C)Au(PPh 3) complexes probably formed in a series of oxidative addition, reductive elimination, and substitution reactions. The structure of Ph 3PMe + [PhC CAuC CPh] − has been determined.