The geometry and intermolecular binding of HCN...BrCl probed by rotational spectroscopy

Article abstract of DOI:10.1016/0009-2614(95)00534-B

Ground-state rotational spectra of several isotopomers of a linear complex formed between HCN and BrCl were observed by pulsed-nozzle, F-T microwave spectroscopy and analysed to give the spectroscopic constants B(0), D(J), χ(Br), χ(Cl), and M(bb)(Br). The order HCN...BrCl of thenuclei was established from the changes in the B(0) values on isotopic substitution. The small fractional electronic charge (.delta~0.05) transferred from Br to Cl on complex formation and the intermolecularstretching force constant (k(σ)~11 N m**-1) estimated from the spectroscopic constants indicates a weak interaction of HCN and BrCl, with little perturbation of the charge distribution of BrCl.