The infrared spectrum of the hydroxylamine dimer

The infrared spectra of the hydroxylamine monomer and dimer, trapped in nitrogen and argon matrices at ca. 17 K, have been obtained. Assignments have been made, based on concentration and matrix diffusion experiments, and on the wavenumber shifts arising from deuteration. The proposed assignments have been checked by comparison with those of a spectrum predicted for the dimer by means of a series of ab initio calculations, reported recently. The spectra have been interpreted in terms of a cyclic, doubly hydrogen bonded dimer of Ci2h symmetry, consistent with that predicted theoretically.