A contribution to the structure determination of Ar–thiophene: the electric dipole moment Original Research Article

Employing pulsed molecular beam Fourier transform microwave spectroscopy (FTMW) an electric dipole moment of μT=μa = 0.5296(13) D was determined for thiophene, C4H4S, from Stark effect measurements. The components of the electric dipole moment along the a and b principal axis system of the Ar–thiophene complex were determined to be μa = 0.01414(11) D and μb = 0.5279(13) D, and compared with the values yielded by ab initio calculations. The experimental and theoretical dipole moments combined with the calculated stabilization energies are only consistent with a structure having Cs symmetry in which the distance between S and the center of mass of the complex is 1.72 Å and Ar is tilted away from S.