Detection of the cyanomidyl radical (HNCN): a new interstellar species
  with the NCN backbone
  We report here the first detection in the interstellar medium of the
cyanomidyl radical (HNCN). Using the Yebes 40m and the IRAM 30m telescopes, we
have targeted the doublets of the $N$=2$-$1, 4$-$3, 5$-$4, 6$-$5, and 7$-$6
transitions of HNCN toward the molecular cloud G+0.693-0.027. We have detected
three unblended lines of HNCN, these are the $N$=6$-$5 doublet and one line of
the $N$=4$-$3 transition. Additionally we present one line of the $N$=5$-$4
transition partially blended with emission from other species. The Local
Thermodynamic Equilibrium best fit to the data gives a molecular abundance of
(0.91$\pm$0.05)$\times$10$^{-10}$ with respect to H$_2$. The relatively low
abundance of this species in G+0.693-0.027, and its high reactivity, suggest
that HNCN is possibly produced by gas-phase chemistry. Our work shows that this
highly reactive molecule is present in interstellar space, and thus it
represents a plausible precursor of larger prebiotic molecules with the NCN
backbone such as cyanamide (NH$_2$CN), carbodiimide (HNCNH) and formamidine
(NH$_2$CHNH).
