Rotational spectrum and structure of the oxetane–argon Van der Waals complex

The rotational spectrum of the Van der Waals complex oxetane–argon has been observed using a molecular beam–Fourier transform microwave spectrometer in the frequency range of 5–18.5 GHz. The complex has Cs symmetry with the argon atom located above the plane of oxetane, 3.57 Å from the center of mass of the ring. The line joining the Ar atom with the center of mass of oxetane makes an angle of ∼10° with the normal to the oxetane plane.