Relative basicities of the oxygen atoms of the Linquist polyoxometalate [Mo6O19]2- and their recognition by hydroxyl groups in radical cation salts based on functionalized tetrathiafulvalene π donors

Electrocrystallization of three hydroxylated donor molecules derived from tetrathiafulvalene (TTF) or ethylenedithiotetrathiafulvalene (EDT-TTF), ie. Me3TTF-CH2OH, EDT-TTF(CH2OH)(2) and TTF(CH2OH)(4), in the presence of [n-Bu4N+](2)[Mo6O19](2-) afforded 2: 1 cation radical salts, [donor(+.)](2)[Mo6O19](2-), whose crystal structures have been solved by X-ray diffraction. In the three different salts complex hydrogen bond networks develop in the solid state where the oxygen atoms of both the hydroxyl groups and the [Mo6O19](2-) anions act as hydrogen bond accepters. The observed hydrogen bonding directed toward one surface, bridging oxygen atom of [Mo6O19](2-) is rationalized by an analysis of ab initio calculations of the distribution of electrostatic potentials.