The rotational spectrum of the chiral tagging candidate molecule, 3,3,3-trifluoro-l,2-epoxypropane (TFO), and of its heterodimer with the argon atom, is obtained using Fourier transform microwave spectroscopy from 5.6 to 18.1 GHz. With a strong, simple rotational spectrum, TFO shows promise for applications in chiral analysis through the conversion of enantiomers into spectroscopically distinct diastereomeric species through noncovalent attachment. The structure of the argon complex of TFO, determined from analysis of the microwave spectrum, is extremely similar to that previously found for ethylene oxide-argon but quite different from that suggested for propylene oxide-argon.