Photolytically-driven carbonyl substitution reactions of (arene)Cr(CO)₃ compounds are limited by low yields and by lack of generality to the type of arene involved. Although electrochemical oxidations of such compounds provide for rapid generation of the monocation [(arene)Cr(CO)₃]⁺, traditional supporting electrolyte anions such as [PF₆]^- decompose the monocation by nucleophilic attack. Hence, cation radicals which are stable on the cyclic voltammetric time scale are unstable on the synthetic time scale. In the present work, studies were performed using a steroidal arene complex, (beta-Estradiol)Cr(CO)₃, 1. It was found that by changing the supporting electrolyte anions to weakly-coordinating anions such as [B(C₆F₅)₄]^- or [B(C₆H₃(CF₃)₂)₄]^-, electrolyte nucleophile attacks were minimized and the monocation was stable on a synthetic time scale. A redox sequence was possible in which 1 was anodically oxidized in the presence of triphenylphosphite (L), giving the cation [(beta-Estradiol)Cr(CO)₂L]⁺, 2⁺, followed by cathodic reduction to give 2, which can be isolated in good yield. The overall mechanism is an example of an electrochemical switching process, and promises to be valuable for the electrochemical preparation of (arene)Cr(CO)₂L complexes.