Rotational Spectrum and Theoretical Calculations of Pyrazole···CO2 Complex:Tetrel and Hydrogen Bond Interactions

The complex between pyrazole and carbon dioxide has been generated in a supersonic jet and characterized using Fourier transform microwave spectroscopy and state of the art CCSD(T) theoretical calculations. The complex presents a planar configuration showing a simultaneous N···C=O n ® π* tetrel bond and a NH···O hydrogen bond. The TS internal rotation barrier that interconverts the oxygen atoms of CO2 has been calculated to be 10 kJ mol-1 at CCSD(T) level. The electronic characteristics of the minimum and TS have been analyzed. Machine Learning methods have been applied to predict the potential energy surface of the pyrazole···carbon dioxide complex.