Emission bands of halogens - Part II. Iodine bands arising in 1g (3Π1g) andΠ2,1g states
The wavelengths of the maxima of all the diffuse bands from 4800 to 2680 A are given. The bands occur in different groups which involve frequency differences of the order of 165 cm.−1, 215 cm.−1 and 360 cm.−1 among the component bands. Five groups of bands with frequency difference of 165 cm.−1 are explained in Paper I. In this paper five groups with frequency differences of 215 cm.−1 and another five groups with frequency differences of 360 cm.−1 among the component bands are discussed. It is shown that they arise in a transition from two initial stable states with frequencies of 215 cm.−1 and 360 cm.−1 to a common set of five different final states which are all unstable. These final states are identified with just those states which are the only theoretically possible ones. The well-known continuum at 3416 A which occurs in emission and in absorption at high temperature is attributed to the transition 1g (3Π1g → Ou− (1Σu−)) in the iodine molecule. The mechanism of the fluorescent bands corresponding to the emission bands is also discussed.