Abstract: Organoiodonium salts, including certain novel symmetrical and unsymmetrical diaryliodonium;. polyiodonium and cyclic iodonium salts are synthesized by a significantly improved electrochemical coupling reaction which provides greater control and selectivity over the end product produced. Reaction mixtures comprising aryliodides and/or aromatic substrates are electrolyzed in novel reaction mediums comprising strong acid electrolyte, lower carboxylic acid, and preferably in the presence of acid anhydride in amounts >10 percent by-weight, and up to 50 percent by-weight or more, to provide a high degree of product selectivity, and at yields which can even be quantitative. The methods are conducted by introducing the electrolysis reaction mixture into an undivided electrochemical cell equipped with a cathode and preferably a conductive carbon anode.