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.
