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

Citation
M. Masino et al., A new type of neutral-ionic interface in mixed stack organic charge transfer crystals: Temperature induced ionicity change in ClMePD-DMeDCNQI, PHYS CHEM P, 3(10), 2001, pp. 1904-1910
Citations number
23
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
ISSN journal
14639076 → ACNP
Volume
3
Issue
10
Year of publication
2001
Pages
1904 - 1910
Database
ISI
SICI code
1463-9076(2001)3:10<1904:ANTONI>2.0.ZU;2-F
Abstract
Raman and polarized infrared spectra of the mixed stack charge transfer cry stals 2-chloro-5-methyl-p-phenylenediamine-2,5-dimethyl-dicyanoquinonediimi ne (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 cross ing of the neutral-ionic borderline appears to be quite different from that of the few known temperature induced neutral-ionic phase transitions. Firs t, the ionicity change is continuous. Furthermore, the onset of stack dimer ization 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.