Research on the development of new molecularbased organic metals and superconductors was stimulated by the first finding of metallic conductivity in a charge-transfer (CT) complex composed of tetrathiafulvalene (TTF, Figure 1) and tetracyanoquinodimethane (TCNQ) 1 and was subsequently accelerated by the discovery of superconductivity in the CT salts of tetramethyltetraselenafulvalene (TMTSF) followed by that in the CT salts of bis (ethylenedithio)-tetrathiafulvalene (BEDT-TTF or ET). 2 Simultaneously, continuous interest in this field has been sustained by synthetic organic chemists, resulting in the production of a huge number of π-electron donors for molecular conductors. 3 The ordinary molecular design of π-donors has evolved mainly from (i) the planarity for a facile formation of donor stacking,(ii) the extension of π-conjugation for a decrease in the on-site Coulombic repulsion involved in the formation of a dicationic species [an increase in delocalization of the generating positive charge (s)], and (iii) the introduction of chalcogen atoms for an increase in dimensionality of the conduction pathway, which was illustrated by the structural characteristics of the ET-based superconductors with nearly isotropic conductivity in the donor sheet including the intermolecular S ‚‚‚S network [two-dimensional (2D) character]. On the contrary, our molecular design strategy for constructing new π-donors is based on the following requirements:(i) extension of the σ-bond framework, which will lead to the lack of planarity, and (ii) reduction of the π-electron system, which will increase the on-site Coulombic repulsion. The motivation in this strategy is to give relief to the tight intermolecular cohesion leading to the stable metallic state so that a synthetic avenue to the realization of organic superconductivity might be opened up, as suggested by a series of studies of the phase diagrams