THE SECOND RESONANCE SYSTEM OF HC3N. NEW RO-VIBRATIONAL GLOBAL ANALYSIS FOR ALL THE EXCITED STATES BELOW 1300 cm−1

The ro-vibrational spectrum of HC3N has been recently the object of a comprehensive study% ootnote{L. Bizzocchi, F. Tamassia, et al., {it Astoph. J. Supp. Ser.} 233:11, 2017} which put together new high-resolution mid-infrared measurements and all existing rotational data for the vibrationally excited states located below ∼ 1000 wn. The resulting global analysis yielded accurate and physically sound spectroscopic parameters for 12 states, thanks to the careful treatment of the l-type resonance effects in bending states and the consideration of various anharmonic resonances, in particular those connecting the polyad of states v4=1, v6=2, v5=v7=1, and v7=4. Here, the extension of the study to the second polyad of interacting states is presented, they are: v4=v7=1, (v6=2,v7=1), (v5=1,v7=2), and v7=5, and are located in the energy interval 1100--1300 wn. New far- and mid-infrared spectra have been recorded at SOLEIL, with a resolution of 0.001 wn, and further measurements of the millimeter and sub-millimeter spectra of the four interacting states have been performed at Garching and Bologna. The results of a new global analysis including all the states below ∼ 1300 wn are presented and discussed.