Structure, optical and electro-physical properties of tetramerized anion-radical salt (N-Xy-Qn)(TCNQ).

The (N-Xy-Qn)(TCNQ) anion-radical salt characterized by tetramerized stacks of the TCNQ acceptor molecules has been synthesized and characterized using vibrational spectroscopy and electrical resistivity measurements. The bond lengths analysis based on the crystal structure data, indicates that the TCNQ molecules are non-uniformly charged with -0.83 e localized on the inner B molecules and -0.

Stabilization of Pancake Bonding in (TCNQ) Dimers in the Radical-Anionic Salt (N-CH-2-NH-5Cl-Py)(TCNQ)(CHCN) Solvate and Antiferromagnetism Induction.

We report a new antiferromagnetic radical-anion salt (RAS) formed from 7,7,8,8-tetracyanquinonedimethane (TCNQ) anion and 2-amino-5-chloro-pyridine cation with the composition of (N-CH-2-NH-5Cl-Py)(TCNQ)(CHCN). The crystallographic data indicates the formation of (TCNQ) radical-anion π-dimers in the synthesized RAS. Unrestricted density functional theory calculations show that the formed π-dimers characterize with strong π-stacking "pancake" interactions, resulting in high electronic coupling, enabling efficient charge transfer properties, but π-dimers cannot be stable in the isolated conditions as a result of strong Coulomb repulsions.