| Popis: |
Difluorodiazirine fluoresces strongly in the vapor phase showing an extensive band system from about 352 to 451 nm and with no background continuum. The fluorescence is assigned as A 1 B 1 (nπ ∗ )- X 1 A 1 and corresponds to the 352 nm absorption system previously studied. The band system is dominated by a progression in ν1″, the a1 N = N stretching vibration, with ν4″, the a1 CF2 symmetrical deformation vibration, showing a shorter progression. The 000 and most others show type B rotational contours but type C bands, involving ν5″ (a2), and probably type A bands, involving ν7″ (b1) and perhaps ν6″ (b1) are also observed. The extremely low intensity of bands involving ν3″ (a1) is surprising but there seems to be no reason to doubt the assignment from infrared and Raman data. There is a strong vibrational perturbation affecting some quite strong bands in a region within about 275 cm−1 of bands 1n0400, where n = 0 – 3. The cause of the perturbation is not known. There is no evidence for the emission spectrum consisting of more than one band system. |
