The hexatriynyl radical (C6H) was initially observed in the Taurus Molecular Cloud by
Suzuki et al.
and in IRC+10216 by
Guélin et al. in the
late 1980s. The Japanese group made their observations with the 45 m telescope at
Nobeyama Radio Observatory,
while the European group employed the
IRAM 30 m telescope.
The formal name of C6H may seem a bit cumbersome, but it
follows standard nomenclature rules for naming organic species. The proper name of triacetylene is
derived from the number of number of carbon atoms (hexa-), the number of C-C triple bonds (tri-),
and the class suffix for triply-bonded hydrocarbons
or hexatriyne. The final "e" is replaced by "yl"
to indicate the radical, hexatriynyl. There are five syllables: hex-a-tri-yn-yl.