IR spectrum of H2SO4 species trapped in low temperature solid CO and in CO containing matrices

Abstract

The IR spectrum of the vapors above neat sulfuric acid trapped in CO enriched argon matrices was studied and compared to their IR spectra in pure CO matrices. We assigned vibrational modes of (OC)·(H₂SO₄), (OC)·(H₂O)·(H₂SO₄), (OC)₂·(H₂SO₄) and (OC)·(SO₃) species isolated in argon matrices in all relevant spectral regions. Bonding between the moieties of the mixed complexes is indicated. These species are formed by surface diffusion within the deposited layer and do not represent a vapor phase equilibrium. No spectral evidence was found for any binary (H₂O)_m·(SO₃)_n or ternary (CO)_l·(H₂O)_m·(SO₃)_n complexes or of ionic species, to indicate a proton transfer below 30 K between the H₂SO₄ and H₂O moieties in either CO enriched or pure CO matrices.