Knowledge Bank

Last year we presented the first rotational analysis of the ground state of the two conformers of allyl isocyanide from 4 GHz to 905 GHz. The analysis of the rotational spectrum of the cis conformer of allyl isocyanide was extended. We resolved Coriolis interactions of $a$ and $b$ types between the excited vibrational states $\nu 1=1$ and $\nu 2=1$, calculated to be at 156 $cm-1$ ($A\prime$) and 167 $cm-1$ ($A″$) respectively (MP2/aug-cc-pvtz), from 150 GHz to 600 GHz}. Strong perturbations were observed in the 150-310 GHz range for low values of the quantum number $Ka$ starting from $Ka=0,1$. The anharmonicities appeared as well at higher frequencies for larger quantum numbers. The two modes were fitted together with the SPFIT/SPCATnderline{\textbf{148}}, 371-377, 1991.} suite of programs and a set of Coriolis parameters was accurately determined. The fit contains more than 3000 lines up to $J=99$ and $Ka=12$ for both modes. We did not detect these species neither in the IRAM 30-m line survey of Orion KL nor in the PRIMOS survey towards SgrB2. Nevertheless, we provided upper limits to their column density in Orion KL. \em{This work was supported by the CNES and the Action sur Projets de l'INSU, PCMI.} %The fit contains more than 3000 lines up to $J=99$ and $ka=12$ for both modes. The proceeding of the analysis to higher $ka$ quantum numbers showed even more complications due to additional interactions with $\nu 3=1$ and $\nu 4=1$. %Zero-kinetic-energy (ZEKE) photoelectron spectroscopy was used to probe the vibrational levels in the ground electronic state of the chlorobenzene cation using a two-color photoionization scheme via the S$1$ electronic state of the neutral nderline{\textbf{102}}(12), XXXX March 1995.}. Exciting through different S$1$ vibrational levels has revealed mixing of some S$1$ normal coordinates in the ground state of the cation. A previously-identified Fermi resonance in the S$1$ state of the neutral is also confirmed by the ZEKE spectra. The adiabatic ionization energy is measured as $73170\pm 5$,cm$\mathrm{<mrow\; data-mjx-texclass="ORD">-1</mrow>}$.