Crystal and Molecular Structure of a Thymine Phototrimer

Abstract
Thymine trimer was isolated from a frozen aqueous solution of thymine which was irradiated with ultraviolet light and was presumably formed through the rearrangement of an initial oxetane photoproduct. X-ray diffraction analysis of a single crystal has confirmed the trimeric diol structure and has established the stereoconfiguration of the molecule. The possible importance of the diol structure in photobiology is pointed out.