AbstractBased on the [2‐(2‐nitrophenyl)propoxy]carbonyl (nppoc) group, six new photolabile protecting groups (2, 8, 9b, 16b, 25b, and 26), each covalently linked to a 9H‐thioxanthen‐9‐one (Tx) unit functioning as an intramolecular triplet sensitizer, were synthesized. Linkers were introduced between the Me group or the aromatic ring of nppoc and the 2‐position of Tx by means of classical organic synthesis combined with Pd catalyzed CC coupling reactions. The new photolabile protecting groups to be used in light‐directed synthesis of DNA chips were attached to the 5′‐O‐atom of thymidine via a carbonate linkage, giving rise to the caged nucleosides 7, 11, 13, 19, 20, and 30.