Solution equilibrium between two structures of Perylene-F 2 TCNQ charge transfer co-crystals

We report on the solution growth of the two known structures of Perylene-F 2 TCNQ charge transfer complexes. The transformation accompanied by a marked morphological change from needle 1:1 to platelet 3:2 crystal structure is observed in the mother liquor. Lattice phonon Raman spectroscopy is used for an easy structure identification of the different morphologies before and after the process. X-ray and lattice phonons spectra of reference samples obtained by physical vapor transport is used to identify the two complexes. A fully spectroscopic analysis of the intramolecular Raman modes is presented to estimate the degree of ionicity, which is found to agree with the value previously reported