The infrared spectra of 15 aliphatic and aromatic zinc sulfinates are given. With zinc p-toluene-sulfinate, run neat as an extremely thin, flat crystal, the symmetric and asymmetric S → 0 peaks were clearly visible at 10.1 μ (990 cm−1) and 10.6 μ (943 cm−1), respectively, and similar absorptions were obtained for the other sulfinates run as Nujol mulls. In distinction to sulfonic acid salts, the sulfinates have practically no absorption in the 8-9 μ (1250-1110 cm−1) region, whereas the sulfonates have no absorption in the 10-11 μ (1000-910 cm−1) thus indicating the analytical value of the spectra in distinguishing these two groups of compounds.
James P. Weidner and Seymour S. Block, "Infrared Spectra of Zinc Sulfinates," Appl. Spectrosc. 23, 337-341 (1969)