B14 Synthesis of a Cobalt Complex by Electrolysis

Description
A cobalt anode is used to synthesize an intensely blue phosphonium salt of tetrachlorocobaltate(II) in acetonitrile. The energy for the reaction is supplied by a battery and voltage measurements are made at both the beginning and middle of the reaction so that a theoretical yield may be calculated using Faraday's Law. Crystals of the phosphonium salt, [Ph₃PH]₂[CoCl₄], recovered from the reaction are shown.

Equation
Co + 4 Cl^- --> CoCl₄²^- + 2 e^-

2 H⁺ + 2 e^- --> H₂

Reference