Reactions of sodium N,N-diethyldithiocarbamate with some organic solvents

Abstract

Sodium N,N-diethyldithiocarbamate reacts smoothly with rnethylene chloride (even in the presence of various transition metal ions) to give the dithiocarbamate ester Et2NC(S)SCH2S(S)CNEtz in very high yield. With chloroform and acetonitrile, proton abstraction occurs followed by partial decomposition of the N,N-diethyldithiocarbamic acid so formed to give diethylammonium N,N-diethyldithiocarbamate.Canadian Journal of Chemistry, 48,3827 (1970) Although there is a very considerable literature on the synthesis of metal N,N-dialkyldithiocarbamate complexes in aqueous solutions (I), it is only recently that reactions between metal halides and sodium N,N-diethyldithiocarbamate (Nadtc) have been examined under anhydrous conditions (2). In almost all cases, the metal-dtc complex is the major product although in certain reactions aimed at the synthesis of pentakis-(N,Ndimethyldithiocarbamato)Nb(V), an organic product, tetramethylthiuram disulfide [(Me2-NCS,),] has been isolated (3). It appears that the metal is reduced to Nb(1V) and the tetramethylthiuram disulfide is produced via the radical Me2NCS2'. In no case, however, has there been mention of the possibility of a reaction between Nadtc and the anhydrous organic solvent.As a continuation of our work on anhydrous metal halide -dtc systems (4), we have carried out reactions between sodium N,N-diethyldithiocarbamate and halides of Nb(V), Ta(V), Pa(V), and Mo and W (in various oxidation states) in several organic solvents under anhydrous and inert atmosphere conditions. These reactions produce not only the expected metal halide -dtc complexes (to be reported in separate papers) but also totally unexpected organic products formed by reactions of the Nadtc with the solvents. Indeed, in some reactions, the organic products are formed in very high yield to the almost complete exclusion of the metal halide -dtc complex. We therefore now report our findings concerning the reactions of sodium N,N-diethyldithiocarbamate with methylene chloride, chloroform, and acetonitrile under strictly anhydrous, oxygen-free conditions.The Nb(V) and T a p ) chlorides and bromides react vigorously and exothermically with Nadtc in methylene chloride to form the appropriate metal-dtc complexes together with varying amounts of an organic product analyzing for C, ,H22N2S,. Formation of the organic product is suppressed if the reaction mixture is cooled below reflux temperatures and the Nadtc added slowly. With the corresponding metal iodides, the complex formation is very slow but the reaction mixture, on vigorous agitation at room temperature for long periods, gives the expected complex and moderate yields of the organic product. If the reaction mixture is heated under reflux, the organic product is formed in almost quantitative yield to the virtual exclusion of the metal-dtc complex. That the complex is not an intermediate in the formation of the organic product is shown by the fact that mixtures of Nadtc and methylene chloride give excellent yields (> 90 %) of the organic material on heating ...

Reactions of Sodium N,N-Diethyldithiocarbamate with the Chlorides and Bromides of Niobium(V), Tantalum(V), and Protactinium(V)

“…In this latter solvent all the reactions are vigorously exothermic and produce the organic product dtc2CH2 (9) in addition to the desired metal complexes. This organic species is formed in negligible yields from the reaction between Nadtc and methylene chloride at room temperature even after prolonged standing but yields increase to over 90% when the mixture is refluxed.…”

“…studies were carried out as previously described (9). Concentrated methylene chloride solutions of the compounds at 40-42 "C were used for the latter work and the methylene protons of the solvent were used as the reference peak (4.73 r) and checked periodically using TMS.…”

“…As part of our studies (1) on reactions between sodium N,N-diethyldithiocarbamate (Nadtc) and anhydrous metal halides in non-aqueous solvents, we have studied reactions (which have been the subject of a preliminary communication (2)), involving the niobium(V), tantalum(V), and protactinium(V) halides. Almost all of the work on dithiocarbamate complexes of these elements has been reported only recently (3).…”

Reactions of Sodium N,N-Diethyldithiocarbamate and Potassium Ethyl Xanthate with some 3d Transition Metal Halides in the presence of 2,2′-Bipyridyl and 1,10-Phenanthroline

“…The reaction between dtc-and CH,Cl, is clearly extremely fast, much faster in fact than the reaction (14) between Nadtc and methylene chloride, which must be refluxed for several hours in order to obtain an appreciable yield of CH,dtc,. It may be that the latter reaction is relatively slow because of the insolubility of Nadtc in methylene chloride, while in the above reaction the dtc-species is in solution and therefore probably able to react with the solvent much more rapidly.…”

“…X-Ray powder photographs and mass spectral studies were carried out as previously described (14). Magnetic moments were measured in a double ended Gouy tube suspended from a semi-micro balance between the poles of a Varian electromagnet.…”