Gas-phase formation and spectroscopic characterization of the disubstituted cyclopropenylidenes <i>c</i>-C<sub>3</sub>(C<sub>2</sub>H)<sub>2</sub>, <i>c</i>-C<sub>3</sub>(CN)<sub>2</sub>, and <i>c</i>-C<sub>3</sub>(C<sub>2</sub>H)(CN)
Astronomy & astrophysics