The rotational spectrum and molecular properties of a hydrogen-bonded complex formed between hydrogen cyanide and hydrogen chloride

Abstract

The rotational spectra of four isotopic species of a weak complex formed between HCN and HCl have been detected and analyzed by using the technique of Fourier-transform microwave spectroscopy conducted in a Fabry–Perot cavity with a pulsed nozzle molecular source. The rotational constants B̃0, centrifugal distortion constants DJ, and nuclear quadrupole coupling constants χaa that result are as follows: Interpretation of the spectroscopic constants leads to the conclusion that the atoms in the complex are colinear in the order HCN⋅⋅⋅HCl, with the weak binding through a hydrogen bond to the N atom HCN. Some quantitative details of the molecular geometry and intermolecular potential function have also been determined for the complex and are compared with those similarly obtained for other members of the series HCN⋅⋅⋅HX and the series B⋅⋅⋅HCl, where B is one of several different proton acceptors.