Recurring chains following addition of atomic hydrogen to acetylene

The C/sub 2/H/sub 3/ radical was prepared by attachment of H atoms to C/sub 2/H/sub 2/. Complex chain reactions ensue: C/sub 2/H/sub 3/ + H/sub 2/ ..-->.. C/sub 2/H/sub 4/ + H; C/sub 2/H/sub 3/ + C/sub 2/H/sub 2/ ..-->.. C/sub 4/H/sub 5/; C/sub 4/H/sub 5/ + H/sub 2/ ..-->.. C/sub 4/H/sub 6/ (1,3-butadiene) + H; C/sub 4/H/sub 5/ + C/sub 2/H/sub 2/ ..-->.. C/sub 6/H/sub 6/ + H (cis addition); C/sub 4/H/sub 5/ + C/sub 2/H/sub 2/ ..-->.. C/sub 6/H/sub 7/ (trans addition); C/sub 6/H/sub 7/ + H/sub 2/ ..-->.. C/sub 6/H/sub 8/ (trans-1,3,5-hexatriene) + H; C/sub 6/H/sub 7/ + C/sub 2/H/sub 2/ ..-->.. C/sub 8/H/sub 9/ (leading to higher members). Relative rate coefficients are derived from product ratios, and the system has been closely matched with a model scheme. The products of the mutual termination reaction of two C/sub 2/H/sub 3/ radicals have been investigated.