Rotational spectrum and structure of the OCS–(CO2)2 trimer

The rotational spectrum of the OCS–(CO2)2 trimer has been assigned. The rotational constants and dipole moment components are consistent with a non-planar, barrel-like structure which approximately aligns the three molecular axes in a parallel fashion. This conformation is in good agreement with rotational constants predicted from a distributed multipole electrostatic interaction which includes atom–atom terms representing dispersion and repulsion contributions.