  It is indisputable that the search for high-temperature superconductivity has
stimulated the work on low-dimensional organic conductors at its beginning.
Since the discovery of true metal-like conduction in molecular compounds more
than 50 years ago, it appeared that the chemical composition and the quasi
one-dimensional crystalline structure of these conductors were determining
factors for their physical properties; materials with incommensurate conduction
band filling favoring the low-dimensional electron-phonon diverging channel and
the establishment of the Peierls superstructure and more rarely
superconductivity at low temperature, while those with commensurate band
filling favor either magnetic insulating or superconducting states depending on
the intensity of the coupling between conductive chains. In addition, the
simple structures of these materials have allowed the development of
theoretical models in close cooperation with almost all experimental findings.
Even though these materials have not yet given rise to true high-temperature
superconductivity, the wealth of their physical properties makes them systems
of choice in the field of condensed matter physics due to their original
properties and their educational qualities. Research efforts continue in this
field. The present retrospective, which does not attempt to be an exhaustive
review of the field, provides a set of experimental findings alluding to the
theoretical development while a forthcoming article will address in more
details the theoretical aspect of low dimensional conductors and
superconductors.
