Figure 11.

Raman spectra of methyl butanoate, sorted by descending effective temperature. Top trace: gas phase spectrum at room temperature. a–e: jet spectra with same substance concentration (1.50 in Figure 10), but different nozzle temperatures $T_{\mathrm{N}}$ and distances between nozzle and laser beam r. (a) T_N = 150 °C, r = 0.5 mm. (b) T_N = 150 °C, r = 1.0 mm. (c) T_N = room temperature, r = 0.5 mm. (d) T_N = room temperature, r = 1.0 mm. (e) like d with 20% helium replaced by argon. Vertical bars at the bottom: selection of intense lines of the four conformers, relative intensities of tgt and tgg scaled by 0.2.