The hexatriynylide ion is the first anion that has been detected in space by radioastronomical means. The experimental measurements were taken from
(1) M. C. McCarthy, C. A. Gottlieb, H. Gupta, and P. Thaddeus, 2006, Astrophys. J., 652, L141.
The ab initio dipole moment was taken from
(2) S. J. Blanksby, A. M. McAnoy, S. Dua, and J. H. Bowie, 2001, Mon. Not. R. Astron. Soc. 328, 89.