Structure and properties of the argon⋅acetylene van der Waals molecule

Abstract

Radio frequency spectroscopy and Stark effect measurements have been carried out on Ar⋅HCCH and Ar⋅DCCD produced in acetylene seeded argon beams. Because of the very small electric dipole moment, μ=0.02697(3) D, only the 110–111 transition and low frequency pure Stark transitions were observed. Observations are only compartible with a T-shaped equilibrium structure with an Ar to acetylene distance of 3.25(1)Å. Deuterium hyperfine data provide a 204.4(10) KHz value for eqQ of acetylene and arcos (√<cos2ϑ≳)=72(1)° for the complex.