|Abstract or Summary
- This research was on the irreversible oxidation of trimethylamine by copper(II) chloride, which takes place at temperatures of about 75° and higher. The coordination of trimethylamine by copper(II) chloride, which is a preliminary reaction to the oxidation, was studied at 0°. The coordination of trimethylamine by the potential reduction product, copper(I) chloride, was also studied at 0°. High vacuum and dry nitrogen glovebox techniques were used in studying the coordination reactions, the stoichiometry of the oxidationreduction reaction, and the hydrolysis of the redox reaction products. Complexes in the copper(II) chloride - trimethylamine system at 0° are a blue-green solid, presumably CuCl ₂ N(CH₃)₃, with a dissociation pressure of several hundred torr, and the yellow-brown solid CuCl₂N(CH ₃)₃' which has a negligible dissociation pressure. The latter, which had been reported previously, exhibits normal paramagnetism at room temperature. Copper(I) chloride and trimethylamine at 0° form the stable complex CuCl N(CH₃)₃. The following reaction can be written for the irreversible thermally induced oxidation-reduction reaction. 2 CuC1₂+ 2 N(CH₃)₃ ----> 2 Cu Cl + (CH₃)₃NH⁺C1⁻ + (CH ₃) ₂ =CH⁺₂ Cl⁻ When the reactants were present in equimolar amounts the reaction stoichiometry was approximately 1:1. The dimethylmethyleneammonium and trimethylammonium caticais were identified by their characteristic infrared frequencies. The presence of the former was also indicated by the identification of its hydrolysis products, formaldehyde and dimethylamine. When trimethylamine was present in excess, the amine: copper(II) chloride reaction stoichiometry was variable, in the range 1.1 to 1.4:1. This is attributed to various complex equilibria involving copper(I) chloride, and to the reaction of trimethylamine with the dimethylmethyleneammonium cation to give a polymeric product. The results on the trimethylamine coordination complexes of copper(I) and copper(II) chloride differ from some previous reports in the literature. The oxidation of trimethylamine by copper(II) chloride closely resembles its previously described oxidation by vanadium(IV) chloride.