Infrafred matrix isolation study of the hydrogen-bonded complexes between ethylene oxide and three hydrogen halides

Abstract Codeposition of M/ethylene oxide and M/HX samples, M = argon or nitrogen, X = Cl, Br, I, produced broad infrared bands that can be assigned to the HX stretching band of 1:1 complexes. The corresponding DX bands are sharp and, as in the case of the HX/ dimethylether/M systems, raise the problem of the origin of the band profiles in these medium strength H-bonded systems. Samples annealing and/or concentration increase produced larger aggregates. One of them is identified as the (HX) 2 — ethylene oxide species characterized, on the basis of H/D isotopic dilution, by a bifid structure which the two HX molecules are equivalent. For HI, some additional results suggest an infrared photodissociation of the 1:1 complex in argon matrices and ion pair formation by increasing HI concentration.