Hydrogen Bonds in Radical Cation Salts of TTF(CH₂OH)₄:  First Complete Series with the Octahedral Rhenium Cluster Anions [Re₆S_8-nCl_6+n]^n-4 (n = 0, 1, 2, 3)

Radical cation salts based on the [Re₆S_8-nCl_6+n]^n-4 (n = 0, 1, 2, 3) cluster anions and on tetrakis(hydroxymethyl)tetrathiafulvalene, TTF(CH₂OH)₄, have been electrochemically synthesized and structurally characterized. In all these salts incorporating each member of this series of isoelectronic and isosteric anions [Re₆S_8-nCl_6+n]^n-4, fully oxidized organic donors are combined in strong eclipsed (TTF(CH₂OH)₄)₂²⁺ dimers. The structure study reveals a complex hydrogen-bond network between hydroxyl groups of organic molecules but also at the organic−inorganic interface. The dimensionality of the organic hydrogen-bond network appears to depend on the cluster/TTF ratio. These molecular materials represent the first complete series of salts associating one particular TTF derivative to the anionic [Re₆S_8-nCl_6+n]^n-4 (n = 0, 1, 2, 3) clusters and allow the study of the effect of the cluster charge on the structural arrangement.