Infrared matrix isolation study of H2SO4 and its complexes with H2O

Abstract

Infrared spectra of H₂SO₄ vapors, which also include H₂O and SO₃, were trapped in argon matrices. Vibrational assignments for monomeric H₂SO₄ were established and additional bands were assigned to the (H₂SO₄)₂, (H₂O)·(H₂SO₄) and (H₂O)₂·(H₂SO₄) species. For the (H₂O)·(H₂SO₄) complex, several isomers are shown to exist, the most stable being H₂O·HOSO₂OH. Temperature reversible changes in several bands of the latter complex are discussed in analogy to the trimeric (H₂O)₃ complex. The H₂O and H₂SO₄ molecules dispersed in the argon solid do not affect the stabilization of a mixed (H₂O)_m·(SO₃)_n complex. No spectral evidence for ionized species due to proton transfer was found in the matrix samples investigated.