Possible spin-allowed fragmentation channels for C₂H₆ following absorption of a photon with energy E_phot < 10 eV. Reactions (1)–(5) were used to describe the photoinduced loss of C₂H₆ in the recent modelling of the stratospheres of Saturn and Jupiter,^1,3 reactions (6) and (7) are implicated in the present data interpretation and the remaining reactions are numbered in order of increasing reaction enthalpy (calculated from data in ref. 47).

Products	ΔrH (0 K)/eV	Dissociation channel
C2H4 + H2	1.34	1
C2H4 + H + H	5.82	2
C2H2 + H2 + H2	3.08	3
CH4 + 1CH2(ã)	4.46	4
CH3 + CH3	3.81	5
CH3 + 3CH2(X̃) + H	8.55	6
C2H5 + H	4.30	7
CH4 + 1CH2(b̃)	5.89	8
C2H3 + H2 + H	6.07	9
C2H2 + H2 + H + H	7.56	10
CH4 + CH + H	8.40	11
CH3 + CH + H2	8.40	12
3CH2(X̃) + 3CH2(X̃) + H2	8.81	13
CH3 + 1CH2(ã) + H	8.94	14
	9.33	15
	9.54	16
1CH2(ã) + 1CH2(ã) + H2	9.59	17