Observation of the C7H radical was reported in 1997 by
Guélin et al. in IRC+10216
using the and based upon the laboratory data
of Travers et al. (see also
McCarthy et al.). The detection does
not appear to have been confirmed by subsequent study to date, though a search in TMC-1 by
Bell et al. did not find the species.
The full name of the C7H radical is
1,3,5-heptatriynylidyne, which indicates that there
are three triple bonds. The figures below show the alternating short and long bond lengths (in Å)
and how the bonding arises from the orbitals of the carbon atom.