Azidoacetylene - interpretation of gas phase infrared spectra based on high-level vibrational configuration interaction calculationsElectronic supplementary information (ESI) available. See DOI: 10.1039/c3cp50268f

Azidoacetylene is a highly explosive substance, which has been synthesized and characterized for the first time quite recently [Banert et al. , Angew. Chem. , Int. Ed. , 2012, 51 , 7515]. As outlined in this work, the vibrational spectrum of azidoacetylene is dominated by strong couplings. For that reason, we have studied the vibrational spectrum of the title compound by gas phase measurements and high-level vibrational structure calculations beyond the harmonic approximation. Based on the interplay of theory and experiment, we were able to identify all fundamentals, strong Fermi resonances and intense overtones, which contribute to the spectrum. The vibrational spectrum of azidoacetylene, being dominated by strong Fermi resonances and intense overtones, has been analyzed by vibrational configuration interaction calculations.