An
electrically conductive D–A–D aggregate composed of
a single component was first constructed by use of a protonated bimetal
dithiolate (complex <b>1H</b><sub><b>2</b></sub>). The
crystal structure of complex <b>1H</b><sub><b>2</b></sub> has one-dimensional (1-D) π-stacking columns where the D and
A moieties are placed in a segregated-stacking manner. In addition,
these segregated-stacking 1-D columns are stabilized by hydrogen bonds.
The result of a theoretical band calculation suggests that a conduction
pathway forms along these 1-D columns. The transport property of complex <b>1H</b><sub><b>2</b></sub> is semiconducting (<i>E</i><sub>a</sub> = 0.29 eV, ρ<sub>rt</sub> = 9.1 × 10<sup>4</sup> Ω cm) at ambient pressure; however, the resistivity
becomes much lower upon applying high pressure up to 8.8 GPa (<i>E</i><sub>a</sub> = 0.13 eV, ρ<sub>rt</sub> = 6.2 ×
10 Ω cm at 8.8 GPa). The pressure dependence of structural and
optical changes indicates that the enhancement of conductivity is
attributed to not only an increase of π–π overlapping
but also a unique pressure-induced intramolecular charge transfer
from D to A moieties in this D–A–D aggregate
