Spin-Peierls, Spin-Ladder and Kondo Coupling in Weakly Localized Quasi-1D Molecular Systems: An Overview

We review the magneto-structural properties of electron–electron correlated quasi-one- dimensional (1D) molecular organics. These weakly localized quarter-filled metallic-like systems with pronounced spin 1/2 antiferromagnetic (AF) interactions in stack direction exhibit a charge decoupling where magnetoelastic coupling picks up to pair into S = 0 singlet dimers. This is well illustrated by observation spin-Peierls (SP) instability (TMTTF)2X Fabre salts and related o-DMTTF donor. instabilities are revealed formation pseudo-gap degrees freedom triggered development SP structural correlations. The divergence these 1D fluctuations, together interchain coupling, drive 3D-SP ground state. More surprisingly, we show that Per2-M(mnt)2 system, undergoing Kondo between metallic Per dithiolate AF coupled ½ (for M Pd, Ni, Pt), enhances instability. Then, consider zig-zag ladder DTTTF2-M(mnt)2 unusual state due combination 4kF localization effect 2kF along ladder. Finally, some specific features concerning coexistence symmetrically different BOW CDW orders organics, nucleation solitons perturbed systems.