Patterned Fluorescence Images Using a Photocleavable NVOC-Protected Quinizarin

We have prepared a NVOC-protected quinizarin derivative for patterned fluorescence image. The NVOC-protected precursor 2 was readily converted to the unprotected quinizarin in the polymer film by photoinduced chemical transformation. Finely-resolved image patterns were obtained when the film was exposed to UV light through a photomask. Since t-Boc-protecting strategy requires photoacid generators which sometimes thermally decompose to give strong acids in the unexposed areas and the NVOC protecting groups are relatively stable under acidic and/or basic environment, the NVOC-protecting strategy should be a useful alternative for the generation of patterned images. Photolabile protecting groups have widely been used in the fundamental and applied research areas. Among various photocleavable protecting groups reported, 6-nitroveratroyl-oxycarbonyl (NVOC) group, an o-nitrobenzyl derivative, has gained much attention due to efficient removal upon UV irradiation. Accordingly, the NVOC protecting strategy has been employed in a variety of solution and solid-phase chemistry. Generation of patterned color images in the polymer film using a photolabile a-methylnitroveratryl-oxycarbonyl (α-MNVOC) protecting group was reported. In this note, we report the first application of the NVOC protecting group to the direct generation of patterned fluorescent images