“…In the field of molecular conductors, 1 the variability offered by organic chemistry gives endless possibilities to modify at will the electroactive molecules, be they organic donor or acceptor molecules or metal complexes with chemical variations on the nature and number of ligands. In that respect, square-planar metal bis(dithiolene) complexes 2,3 provide a huge playfield as the two R 1 and R 2 substituents on the MS 2 C 2 R 1 R 2 metallacycles can be engineered to control their shape and symmetry, particularly if R 1 ≠ R 2 , 4,5 or if R is chiral, 6,7 but also their HOMO/LUMO energies and HOMO–LUMO gap 8 (and associated optical properties in the NIR), 9,10 the extend of intermolecular interactions such as the S⋯S overlap interactions but also hydrogen 11 or halogen 12 bonding interactions. The most successful complex in these series are the [M(dmit) 2 ] ones (Chart 1, dmit: 1,3-dithiole-2-thione-4,5-dithiolate), which provided a large number of mixed-valence conducting (and even superconducting) salts, 2,5 when associated with closed-shell (ammonium, phosphonium, sulfonium, …) or open-shell (tetrathiafulvalenium, ferricenium, …) cations.…”