Rotational spectrum of anisole-CO2: Cooperative C•••O tetrel bond and C-HO hydrogen bond

Rotational spectrum of the 1:1 anisole-CO2 complex has been investigated using a pulsed jet Fourier transform microwave spectrometer supplemented with quantum chemical calculations. In the pulsed jet, only one isomer has been observed which is characterized by a dominant C center dot center dot center dot O tetrel bond and two C-H center dot center dot center dot O-CO2 weak hydrogen bonds. Different theoretical methods predict different orders of relative energies of plausible conformations. The experimental observation is most consistent with the theoretical estimation at the B3LYP-D3(BJ)/6-311++G(d, p) level of theory. Johnson's non-covalent interaction, quantum theory of atoms in molecules and natural bond orbital analyses have been applied to better understand the nature of non-covalent interactions at play in the anisole-CO2 complex.

Automated summary

The rotational spectrum of the 1:1 anisole-CO2 complex was studied using a pulsed jet Fourier transform microwave spectrometer and quantum chemical calculations. Experimental observations and theoretical estimations at the B3LYP-D3(BJ)/6-311++G(d, p) level of theory suggested the presence of a dominant C center dot center dot center dot O tetrel bond and two C-H center dot center dot center dot O-CO2 weak hydrogen bonds in the complex. Johnson's non-covalent interaction, quantum theory of atoms in molecules, and natural bond orbital analyses were employed to understand the nature of non-covalent interactions in the anisole-CO2 complex.