2022 Volume 16 Issue 1 Pages A0123-
Molecular conductors demonstrate science of π electron systems where low-dimensionality and strong electron correlation play indispensable roles. Molecular conductors have been developed by collaboration between chemistry and physics. Chemistry prepares new materials that open new physics. On the other hand, deep insight of physics is fed back to new concepts of material design. This review describes cation radical salts of TTF (Tetrathiafulvalene) derivatives, DCNQI (N,N′-Dicyanobenzoquinonediimine)-Cu π-d systems, frustrated dimer-Mott systems, and single-component molecular Dirac electron systems from viewpoints of multi-dimensional and multi-orbital characters.