  Mysterious high temperature structureless transitions in (TMTTF)2X compounds
have been discovered in mid 80's (Coulon, Lawersanne,vet al), but left
unexplained and abandoned, together with other warnings from structural effects
(Moret, Pouget, et al), with dramatic consequences for the whole field.
Recently their nature has been identified as the ferroelectricity (Nad,
Monceau, et al) and, more generally, the charge disproportionation (Brown, et
al). New phenomena unify an unusual variety of concepts: ferroelectricity of
good conductors, structural instability towards Mott- Hubbard state, Wigner
crystallization in a dense electronic system, ordered 4kF density wave,
richness of physics of solitons, interplay of structural and electronic
symmetries. The ferroelectric state gives rise to several types of solitons
carrying electronic charge, a noninteger charge, spin or both spin and charge
in special cases. They are clearly observed via conductivity, electric and
magnetic susceptibilities. Solitons are challenging for optics where they
already seem to determine the pseudogap in absorption. Various features also
appear, or are expected, from collective electronic and coupled electron-phonon
modes. REFERENCES: cond-mat/0012237 cond-mat/0304076 cond-mat/0304483
cond-mat/0306006
