Abstract
Emphasis has been placed to the phenomena which seem to clearly show the nature of the one-dimensional array of TCNQ and to the X-ray analyses of two types of the superlattice structures of a molecular complex and an anion radical salt of TCNQ. The subjects outlined are as follows: (1) the possibility of a neutral↔ionic transition of the ground state charge distribution in the mixed-stacking columns of charge transfer complexes, (2) the relation between electrical conductivities and columnar structures of TCNQ anion radical salts, (3) Peierls instability of one-dimensional metal, (4) charge distribution and localization of excess electrons in TCNQ columns, (5) the evidence for monomer-dimer transition of alkali metal-TCNQ from X-ray diffraction patterns of these salts, (6) observation of X-ray satellite reflexion and the analysis of the sinusoidal structure of PTZ-TCNQ, (7) X-ray analysis of the anti-phase domain structure and stacking disorder of NH4-TCNQ.
