Methylated metals

H-1,2-Oxazine, 3,6-dihydro-6-(2-pyridyl)-mass spectra, 2, 529 2H-1,2-Oxazine, tetrahydro-synthesis, 2, 92 4H-l,2-Oxazine, 5,6-dihydro-pyrolysis, 3, 999 synthesis, 3, 1017 tautomerism, 3, 999 4H-1,2-Oxazine, 5,6-dihydro-3-methyl-metallation, 1, 484 4H-l,2-Oxazine, 5,6-dihydro-3-nitro-reactions, 3, 1000 6H-l,2-Oxazine, 3,5-diphenyl-stability, 3, 997 synthesis, 3, 1014... 

Quinoline, 8-mercapto-2-methyl-metal complexes, 2, 800 Quinoline, 2-methyl-8-(methylthio)-metal complexes, 2,801 Quinoline, 8-methylthio-metal complexes, 2, 801 Quinoline-2-carboxylic-acid, 8-hydroxy-methyl ester... 

Tin is shown to be methylated by organisms and other environmental factors. Organic tin compounds are much more toxic than the inorganic ones. This increase in toxicity due, e.g., to methylation is attributable to the increasing membrane permeability of the methylated metal compounds and to the remaining sensibility to react with sulfhydryl groups of proteins, especially of enzyme proteins. 

Hamasaki, T., H. Nagase, Y. Yoshioka, and T. Sato. 1995. Formation, distribution, and ecotoxicity of methyl-metals of tin, mercury, and arsenic in the environment. Crit. Rev. Environ. Sci. Technol. 25 45-91. 

Fig. 5. The Arrhenius plot of kl/k2i. e, dimethyl zinc O, trimethyl gallium , trimethyl indium. % figures are in terms of the theoretical yield of methyl radicals that would be obtained if all methyl-metal bonds were broken. All points are corrected to 13 torr pressure (toluene+0.3-2.5 % alkyl).

It would be desirable to be able to use data such as that given in Table 12 to predict Dt values for other methyl metallic alkyls and to set a pattern for ethyl and possibly higher alkyls. These dissociation energies should be approximately equal to the kinetic activation energy for the first stage of dissociation in a nonchain decomposition or to the activation energy of the initiation step in a chain decomposition. 

Tracer studies with 13C showed that the carbon of methoxy species formed in CO hydrogenation appeared as the central C atom of isobutylene.531 Methoxy was shown to be reduced to surface methyl species that was transformed to surface acetyl group via insertion of CO into the methyl-metal bond. Aldol condensation of C2 oxygenates with formaldehyde affords iso-C4 products.532 Earlier results of a different approach for isosynthesis using metal-zeolite catalyst systems are summarized in a 1998 review.533... 

Table 4.71. 13C Chemical Shifts (c>c in ppm) and Carbon-Metal Coupling Constants (JCM in Hz) of Representative Methyl-Metal Compounds [474], Coupling Constants refer to the more Abundant Metal Isotope.

Methyl-metal bond cleavage also occurred in the reactions of gold(I), gold(III), and platinum(II) compounds with thiols and selenols (207-209). The reactions of gold(I) and platinum(II) complexes were much faster than those of gold(III), due to the operation of a radical chain mechanism in the former cases. For the reactions with diphenylphosphine, however, the following order of reactivity was found (209) ... 

Benzohydroxamic acid dioxouranium complexes, 507 metal complexes, 506, 507 as metal precipitant, 506 Benzohydroxamic acid, iV-methyl-metal complexes, 506 Benzohydroxamic acid, N-phenyl-metal complexes, 507 reactions with carboxylic acids, 507 as metal precipitant, 506 titanium complexes, 506 Benzohydroxamic acid, A -(o-tolyl)-as metal precipitant, 506 Benzohydroxamic acid, N-wi-tolyl-p-methoxy-metal complexes, 506 Benzoic acid, dihydroxy-beryllium(II) complexes, 481 Benzoic acid, o-mercapto-esters... 

Formamide, diphenyl-metal complexes, 491 Formamide, -methyl-metal complexes synthesis, 492... 

Hydrosulfido complexes, 517 bonding, 519 reactivity, 519 structures, 519 synthesis, 518 types, 518 Hydroxamates metal complexes, 505-508 Hydroxamic acid, N-methyl-metal complexes, 507 Hydroxamic acid, phenyl-metal complexes stability, 506 Hydroxamic acids... 

Hydroxylamido complexes, 101 Hydroxylamine, N.N-di-f-butyl-metal complexes, 798 Hydroxylamine, N,N-diethyl-metal complexes, 798 Hydroxylamine, N-methyl-metal complexes, 798... 

Quinaldohydroxamic acid as metal precipitant, 506 Quinodimethane, tetracyano-metal complexes, 263 Quinoline, 8-(alkylthio)-metal complexes, 801 Quinoline, 8-hydroxy-metal complexes, 795 Quinoline, 8-hydroxy-2-methyl-cobalt(II) complexes, 795 Quinoline, 8-mercapto-metal complexes, 800 Quinoline, 8-mercapto-2-methyl-metal complexes, 800 Quinoline, 2-methyl-8-(methylthio)-metal complexes, 801 Quinoline, 8-methylthio-metal complexes, 801 8-Quinolineselenol metal complexes, 807 Quinones... 

---