Modern Polymer Spect..

3.19 A Workrd Example 187
Figure 3-50. Ternperaturedependent
infraied spectra of
n-nonadecane showing changes
through the solid-cc (T - 22OC)
and r-liquid (T - 29 "C) phase
transitions
i I , I
1400 1360 1320 I290 1240
v cm-'
(p) At T, the A, component of the factor group splitting of the CH2-bending
mode near 1417 cm-' practically disappears, even if not completely (Figure
3-53).
(q) At T, the valley between the A, (2845 cm-') and Bl, (2882 cm-') modes of the
C-H-stretching region becomes emptier and the band at 2845 cm- ' sharpens.
(r) At T, a slight increase in the scattering near 1090 cm-l is observed.
(s) At T, on the lower frequency side of the well-isolated peak near 890 cm-' (/3
mode) two weak bands are observed at 866 and 844 cm-' (Figure 3-54).