The time-resolved Raman observation of a prototype of the hetero-atom three electron bonds (-X-OH) that often form on encounter of the OH radical with chemical species in water is reported. In spite of their wide chemical and biochemical importance, no experimental structural information exists, thus far, on any such bond in solution or in the gas phase. The nature of the >S-O bond formed on the reaction of the OH radical with dimethyl sulfide in water, investigated in the present work, would necessitate a reexamination of the existing reaction mechanisms in related biological systems and development of the appropriate computational methods.