A new method for electrocrystallization of AgTCNQF4 and Ag2TCNQF4 (TCNQF4 = 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) in acetonitrile

Semiconducting AgTCNQF 4 (TCNQF 4 = 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) has been electrocrystallized from an acetonitrile (0.1 M Bu 4 NPF 6 ) solution containing TCNQF 4 and Ag(MeCN) 4 + . Reduction of TCNQF 4 to the TCNQF 4 1− anion, followed by reaction with Ag(MeCN) 4 + forms crystalline AgTCNQF 4 on the electrode surface. Electrochemical synthesis is simplified by the reduction of TCNQF 4 prior to Ag(MeCN) 4 + compared with the analogous reaction of the parent TCNQ to form AgTCNQ, where these two processes are coincident. Cyclic voltammetry and surface plasmon resonance studies reveal that the electrocrystallization process is slow on the voltammetric time scale (scan rate = 20 mV s −1 ) for AgTCNQF 4 , as it requires its solubility product to be exceeded. The solubility of AgTCNQF 4 is higher in the presence of 0.1 M Bu 4 NPF 6 supporting electrolyte than in pure solvent. Cyclic voltammetry illustrates a dependence of the reduction peak potential of Ag(MeCN) 4 + to metallic Ag on the electrode material with the ease of reduction following the order Au