Complexes of an argon atom with the linear anions HCC − and HC 4−: results of coupled cluster calculations

Abstract

Large-scale coupled cluster calculations have been carried out for the complexes of an argon atom with the linear anions HCC − and HC 4 −. In both cases, almost T-shaped structures are energetically favoured. Their equilibrium dissociation energies ( D e) are predicted to be 501(5) and 507(5) cm −1, respectively. In contrast to the isoelectronic neutral systems Ar + HCN and Ar + HC 3N, no energy minima are found for the ‘hydrogen-bonded’ configurations. While the complex Ar ⋯ HCC − is rather flexible, Ar ⋯ HC 4 − appears to be fairly rigid, quite similar to isoelectronic Ar ⋯ HC 3N or Ar ⋯ HC 4H.