We have studied the effect of the order-disorder transition of the orientation of Perchlorate (007) ions on the vibrational modes of ethylenediamine (NH2CH2CH2NH2) in [M(en)2][Pt(en)2Cl2](C104)4, where en is ethylenediamine and M = Pt or Pd ion, by means of Raman spectroscopy. Upon the transition into the ordered phase, the spectra due to the CH stretching modes split into two groups on account of the difference in the coordination sites of Pt(II)[Pd(II)] and Pt(IV). The spectral separation between the two groups is about 20 cm-1 at 270 K. On the other hand, the NH stretching and the NCCN skeleton modes exhibit no splitting. These results indicate that the protons of the methylene (CH2) group of the ethylenediamine have a strong interaction with the internal motion of the Perchlorate ions which bind the CDW chains.
- Raman scattering
- one-dimensional mixed-valence
- order-disorder transition
ASJC Scopus subject areas
- Physics and Astronomy(all)