Exotic new species are frequently proposed as candidates for possible astronomical detection. In 2019,
Cabezas and co-workers reported a study of
a number of linear cyanoacetylide molecules with a M–C≡C–C≡N structure containing the
alkali metals Li and Na and
alkaline earth metals Mg and Ca. The lightest
of the species they investigated was lithium cyanoacetylide, LiCCCN (or LiC3N). The work combined
theoretical predictions, experimental measurements, and astronomical observations. Rotational ransitions from
J=27-26 to J=44-43 were sought in a 3 mm line survey of IRC +10216 and were not detected.
The upper limit of the column density
of both LiCCCN and NaCCCN is 8x1010 cm-2.
To date, there has been no definitive detection of any molecule containing Li in space. Although there is
some evidence for LiH, the most recent
search for it with
ALMA did not detect it toward Sgr B2 or W49N. There
evidently have been no searches reported to date for other Li-containing compounds that might reasonably
be expected to be present in space, including LiF, LiCl, and LiCN.