A new type of neutral-ionic interface in mixed stack organic charge transfer crystals: Temperature induced ionicity change in ClMePD-DMeDCNQI

作者：Masino M; Girlando A^*; Farina L; Brillante A

来源：Physical Chemistry Chemical Physics, 2001, 3(10): 1904-1910.

DOI：10.1039/b100243k

Raman and polarized infrared spectra of the mixed stack charge transfer crystals 2-chloro-5-methyl-p-phenylenediamine-2,5-dimethyl-dicyanoquinonediimine (ClMePD-DMeDCNQI) are reported as a function of temperature. A detailed spectral interpretation allows us to gain new insight into the temperature induced neutral-ionic transition in this compound. In particular, the crossing of the neutral-ionic borderline appears to be quite different from that of the few known temperature induced neutral-ionic phase transitions. First, the ionicity change is continuous. Furthermore, the onset of stack dimerization precedes, rather than accompanies, the neutral-ionic crossing. The (second order) phase transition is then driven by the dimerization, but the extent of dimerization is in turn affected by the ionicity change.

• 出版日期2001