Electrochemical Formation of Contacts between Platinum or Gold Electrodes with the Organic Charge-Transfer Salts Tetrathiafulvalenium Bromide (TTFBrx, x = 0.74−0.79) or Bis(tetramethyltetraselenafulvalenium) Perchlorate ((TMTSF)2ClO4)

Conducting crystals of the charge-transfer salts TTFBrx (tetrathiafulvalenium bromide) and (TMTSF)2ClO4 (bis(tetramethyltetraselenafulvalenium) perchlorate) were studied. The needle-shaped crystals were grown between pairs of platinum or gold electrodes by oxidative electrodeposition. An electrical connection was formed when a crystal growing from one electrode (base electrode) encountered the second electrode (target electrode). It was found that electrical contacts form even if the potential of the target electrode is considerably lower than the electrocrystallization potential of the charge-transfer salt. Contacts between crystal and target electrode are surprisingly adherent, as seen in experiments where crystals detach from the base electrode and stick to the target electrode. They can also be disconnected and reconnected reversibly by manipulation of the potential of the base electrode, which results in dissolution and recrystallization of the organic salt in the vicinity of the target electrode.