Electrochemical Synthesis of Tetraethylammonium Tetrathiooxalate

Tetrathiooxalate was originally claimed to result from the reduction of CS2 with sodium. Jeroschewski demonstrated a practical synthesis of C2S42- by suppressing its condensation with CS2. His method involves the electrolytic reduction of CS2 in the presence of a cation that forms a poorly soluble salt with tetrathiooxalate. Additional features of the Jeroschewski method are the use of low temperatures and dilute solutions, both of which minimize the condensation side reaction. This chapter focuses on a procedure that is an adaptation of Jeroschewski's method, but uses a simpler apparatus. Solid (Et4N)2C2S4 can be stored under N2 or in a vacuum for months without decomposition. The most useful check of the purity is by optical spectroscopy. It is soluble in highly polar solvents including water.