Overlapping $B^{3}e??±_{0u}a?? X^{1}e??′^{+}_{g}$ and $^{1}e??±_{1u} a?? X^{1}e??′^{+}_{g}$ non-radiative characteristic of Br2 vapour in the wavelength region 505a€“541 nm

摘要

The vibronic vapour phase photoacoustic spectrum of Br2 in the wavelength region 505a€“541 nm (19796a€“18480 cm-1) has been recorded using microphone as well as pump-probe method. Discrete vibronic bands superimposed on a monotonically increasing continuum background towards the dissociation limit results from the overlapping $B^{3}e??±^{+}_{0u}a?? X^{1}e??′^{+}_{g}$ and $^{1}e??±_{1u}a?? X^{1}e??′^{+}_{g}$ electronic transitions. Vibronic bands originating from e?‘￡'' = 0 have been used to estimate the relative rate of non-radiative relaxation as a function of the excited state e??μ $^{3}e??±_{0u}$ vibrational quantum number e?‘￡'. A comparison with the optical absorption spectroscopy of Br2 leads to the identi???cation of three broad spectral regions between 505 and 541 nm (19796 and 18480 cm-1) on the basis of different non-radiative relaxation processes.