Me(3)TTF-PO3H2, a redox phosphonic acid and its monoanilinium salt [PhNH(3)(+)][Me(3)TTF-PO(OHO-], the electrocrystallized neutral (zwitterionic) pi radical [Me(3)TTF-PO(OHO-](.+), and their associated lamellar constructions in the solid state

The reaction of Me(3)TTFLi (TTF = tetrathiafulvalene) with CIP(O)-(OEt)(2) followed by hydrolysis with Me(3)SiBr affords the novel pi-donor molecule trimethyltetrathiafulvalenylphosphonic acid (Me(3)TTF-PO3H2) in a partially oxidized form. Subsequent reduction and neutralization with aniline gives the corresponding phosphonate monoanilinium salt. A unique hydrogen-bonded hexagonal net is identified within the lamellar structure of [PhNH(3)(+)][Me(3)TTF-PO(OHO-], which is described by analogy with the anti-CaSi2 structure type. Electrocrystallization of the former salt yields single crystals of a neutral (zwitterionic) pi radical, formulated as [Me(3)TTF-PO(OHO-](.+). Their structure reveals the presence of hydrogen-bonded molecular ribbons whose association creates a novel layered architecture similar to that obtained within radical cation salts of pi-donor molecules of larger spatial extension. The analysis of the calculated HO-MO-HOMO intermolecular interaction energies demonstrates that these slabs contain strong pi-pi intermolecular interactions despite the nonexistence of any 2D network of short S ... S contacts. The spin susceptibility of [Me(3)TTF-PO-(OHO-](.+), determined by single-crystal ESR measurements, is characteristic of triplet excitons, the origin of which may be understood from the electronic structure of the compound.