Dimethyl sulfoxide, reaction with metal

Precaution Flamm. reacts violently with water hydrolyzed in moist air forming HCI violent reactions with Al, NH3, K, Na, acetone, dimethyl sulfoxide, water, oxidizers, metals, toluene Hazardous Decomp. Prods. Heated to decomp., emits very toxic fumes of SOx and Cl ... 

Nucleophilic Substitution Route. Commercial synthesis of poly(arylethersulfone)s is accompHshed almost exclusively via the nucleophilic substitution polycondensation route. This synthesis route, discovered at Union Carbide in the early 1960s (3,4), involves reaction of the bisphenol of choice with 4,4 -dichlorodiphenylsulfone in a dipolar aprotic solvent in the presence of an alkaUbase. Examples of dipolar aprotic solvents include A/-methyl-2-pyrrohdinone (NMP), dimethyl acetamide (DMAc), sulfolane, and dimethyl sulfoxide (DMSO). Examples of suitable bases are sodium hydroxide, potassium hydroxide, and potassium carbonate. In the case of polysulfone (PSE) synthesis, the reaction is a two-step process in which the dialkah metal salt of bisphenol A (1) is first formed in situ from bisphenol A [80-05-7] by reaction with the base (eg, two molar equivalents of NaOH),... 

Solvent for Electrolytic Reactions. Dimethyl sulfoxide has been widely used as a solvent for polarographic studies and a more negative cathode potential can be used in it than in water. In DMSO, cations can be successfully reduced to metals that react with water. Thus, the following metals have been electrodeposited from their salts in DMSO cerium, actinides, iron, nickel, cobalt, and manganese as amorphous deposits zinc, cadmium, tin, and bismuth as crystalline deposits and chromium, silver, lead, copper, and titanium (96—103). Generally, no metal less noble than zinc can be deposited from DMSO. 

Zirconium tetrachloride is instantly hydrolyzed in water to zirconium oxide dichloride octahydrate [13520-92-8]. Zirconium tetrachloride exchanges chlorine for 0x0 bonds in the reaction with hydroxylic ligands, forming alkoxides from alcohols (see Alkoxides, METAl). Zirconium tetrachloride combines with many Lewis bases such as dimethyl sulfoxide, phosphoms oxychloride and amines including ammonia, ethers, and ketones. The zirconium organometalLic compounds ate all derived from zirconium tetrachloride. 

Ce4+ is a versatile one-electron oxidizing agent (E° = - 1.71 eV in HC10466 capable of oxidizing sulfoxides. Rao and coworkers66 have described the oxidation of dimethyl sulfoxide to dimethyl sulfone by Ce4+ cation in perchloric acid and proposed a SET mechanism. In the first step DMSO rapidly replaces a molecule of water in the coordination sphere of the metal (Ce v has a coordination number of 8). An intramolecular electron transfer leads to the production of a cation which is subsequently converted into sulfone by reaction with water. The formation of radicals was confirmed by polymerization of acrylonitrile added to the medium. We have written a plausible mechanism for the process (Scheme 8), but there is no compelling experimental data concerning the inner versus outer sphere character of the reaction between HzO and the radical cation of DMSO. 

Mixtures of the sulfoxide with metal salts of oxoacids are powerful explosives. Examples are aluminium perchlorate, sodium perchlorate and iron(III) nitrate [1], The water in hydrated oxosalts (aluminium perchlorate, iron(III) perchlorate, iron(III) nitrate) may be partially or totally replaced by dimethyl (or other) sulfoxide to give solvated salts useful as explosives [2], Metal nitrates and perchlorates solvated with DMSO are generally powerfully explosive, and under certain conditions a violent reaction is easily triggered [3], Several other explosions involving perchlorates and the sulfoxide have been reported. 

In addition to the unconventional methods of the formation of siloxane bonds such as those discussed earlier, the non-hydrolytic reactions of chlorosilanes in the presence of dimethyl sulfoxide, 7 and the reaction of dichlorosilanes with metal oxides,111 a new method has recently been discovered which involves the condensation of alkoxysilanes with organohydrosilanes with the release of hydrocarbon.112... 

When the radicals, coordinated with a catalyst, produce polymers, the catalyst is precipitated and inactivated by forming an inseparable bond with polymers, especially in a nonpolar solvent such as benzene. However, a polar solvent such as butyric acid or dimethyl sulfoxide is believed to expel the coordinated peroxy radical from the metal, thereby keeping it active during the reaction. 

The 1-fluoroquinuclidinium fluoride (NFQNF, 2) precipitates during the reaction and, after treatment with hot, dry acetone to remove quinuclidinium fluoride, is obtained as an extremely hygroscopic white solid which can be assayed iodometrically (reaction with aqueous acetonic KI occurs instantaneously at rt). l-Fluoroquinuclidinium fluoride (2) is readily soluble in water, methanol, ethanol, trifluoroacetic acid, and ethyl acetate, and reasonably so in acetonitrile, but appears to be insoluble in alkanes, arenes, chloromethanes, acetone, diethyl ether, tetrahy-drofuran, dimethylformamide and dimethyl sulfoxide. The fluoride 2 has a melting point of 126-128°C (dec.) and is less flammable than quinuclidine in air, igniting only on direct contact with a flame or after prolonged heating on a metal plate. It does not explode when struck with a hammer.73... 

The complications which result from the hydrolysis of alkali metal cyanides in aqueous media may be avoided by the use of non-aqueous solvents. The one most often employed is liquid ammonia, in which derivatives of some of the lanthanides and of titanium(III) may be obtained from the metal halides and cyanide.13 By addition of potassium as reductant, complexes of cobalt(O), nickel(O), titanium(II) and titanium(III) may be prepared and a complex of zirconium(0) has been obtained in a remarkable disproportion of zirconium(III) into zirconium(IV) and zirconium(0).14 Other solvents which have been shown to be suitable for halide-cyanide exchange reactions include ethanol, methanol, tetrahydrofuran, dimethyl sulfoxide and dimethylformamide. With their aid, species of different stoichiometry from those isolated from aqueous media can sometimes be made [Hg(CN)3], for example, is obtained as its cesium salt form CsF, KCN and Hg(CN)2 in ethanol.15... 

Coordinated a-amino amides can be formed by the nucleophilic addition of amines to coordinated a-amino esters (see Chapter 7.4). This reaction forms the basis of attempts to use suitable metal coordination to promote peptide synthesis. Again, studies have been carried out using coordination of several metals and an interesting early example is amide formation on an amino acid imine complex of magnesium (equation 75).355 However, cobalt(III) complexes, because of their high kinetic stability, have received most serious investigation. These studies have been closely associated with those previously described for the hydrolysis of esters, amides and peptides. Whereas hydrolysis is observed when reactions are carried out in water, reactions in dimethyl-formamide or dimethyl sulfoxide result in peptide bond formation. These comparative results are illustrated in Scheme 91.356-358 The key intermediate (126) has also been reacted with dipeptide... 

Langer, H. G., Redistribution reactions with Group IV metal compounds in dimethyl-sulfoxide (DMSO), Tetrahedron Letters, 43 (1967). 

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