 The gas phase structure of methanesulfenic acid was found by microwave spectroscopy (rotational spectroscopy) to be CH3–S–O–H.Sulfenic acids can be stabilized through steric effects, which prevent the sulfenic acid from condensing with itself to form thiosulfinates, RS(O)SR, such as allicin from garlic.Through the use of X-ray crystallography, the structure of such stabilized sulfenic acids were shown to be R–S–O–H.