Structural investigations into a new polymorph of F₄TCNQ: towards enhanced semiconductor properties

During the course of research into the structure of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F₄TCNQ), C₁₂F₄N₄, an important compound in charge-transfer and organic semiconductor research, a previously unreported polymorph of F₄TCNQ was grown concomitantly with the known polymorph from a saturated solution of dichloromethane. The structure was elucidated using single-crystal X-ray diffraction and it was found that the new polymorph packs with molecules in parallel layers, in a similar manner to the layered structure of F₂TCNQ. The structure was analysed using Hirshfeld surface analysis, fingerprint plots and pairwise interaction energies, and compared to existing data. The structure of a toluene solvate of F₄TCNQ is also reported.