Adiabatic dissociation of photoexcited chlorine molecules

Photofragmentation study of Cl2 using ion imaging

“…The spectrum has been attributed to transitions between the Cl 2 ͑X 1 ⌺ g ) ground electronic state and the purely repulsive 1 ⌸ u and B 3 ⌸ u excited electronic states. A correlation diagram between the atomic states of free Cl and the molecular electronic states of Cl 2 has been reported by Mulliken, 1 Herzberg, 2 Li et al 3 and Matsumi et al, 4 according to which the strong spin-orbit interaction in atomic chlorine mandates a Hund's case ͑c͒ description of Cl 2 . 5 Consequently, the proper notations for the molecular electronic states are 0 g ϩ ͑X 1 ⌺ g ), 1 u ( 1 ⌸ u ), for the states correlating to Cl( 2 P 3/2 )ϩCl( 2 P 3/2 ), and 0 u ϩ ͑B 3 ⌸ u ) for the state correlating to Cl( 2 P 3/2 )ϩCl( 2 P 1/2 ) 2 .…”

A complete quantum mechanical study of chlorine photodissociation

“…Fully state specific determination of the fragments was achieved in 1988 by Li et al, 6 using (3+1) resonantly enhanced multiphoton ionization (REMPI) to detect the atomic products from photodissociation at 325 nm. This confirmed the overwhelming dominance of the (Cl + Cl) channel, and led these researchers to conclude that chlorine photodisso-ciation was 'highly adiabatic' in character; proceeding almost entirely on a single potential energy surface.…”

“…The (3+1) REMPI scheme employed in Ref. 6 was insufficiently sensitive to detect excited state chlorine atoms. A similar study in 1989 by Matsumi et al 7 used more sensitive (2+1) REMPI, and concluded that the ratio between the ground and excited state Cl atoms at 351 nm was in the ratio of 100:1.…”

“…Considered to be a vital component in the mechanism of ozone depletion, 1 Cl 2 is one of the ten most produced chemicals in industry. 2 It has also been a testing ground for the development of new techniques, [3][4][5][6][7] providing the basis for several ground-breaking studies on photofragment polarization, 5,8,9 in particular the first paper to link the fully quantum mechanical expressions of Siebbeles et al 10 to ion imaging. 5 Much easier to study experimentally than hydrogen or fluorine, yet still sufficiently simple to be amenable to detailed theoretical studies, Cl 2 photodissociation has been the target of several high level potential energy surface calculations and, crucially, of angular momentum polarization studies over a range of wavelengths throughout its UV absorption spectrum.…”

Photofragmentation of Cl2 at 308 nm

“…The ultraviolet absorption spectrum of molecular chlorine between 250 and 450nm has been attributed to transitions between the C12(Xlg) ground electronic state and the purely repulsive 1II, and B3I-I, excited electronic states. A correlation diagram between the atomic states of free C1 and the molecular electronic states of C12 has been reported by Mulliken [1], Herzberg [2], Li et al [3] and Matsumi et al [4], according to which the strong spin-orbit interaction in atomic chorine mandates a Hund's case (e) description of C12 [5].…”