The invention relates to novel caging-group-free photoactivatable fluorescent dyes having the structural formula I:

##STR00001##

as well as to the corresponding photoactivated fluorescent dyes having the structural formula II:

##STR00002##

The invention further relates to the use of the photoactivatable compounds as such or after photoactivation, in particular as fluorescent tags, analytical reagents and labels in optical microscopy, imaging techniques, protein tracking, nucleic acid labeling, glycan analysis, capillary electrophoresis, flow cytometry or as a component of biosensors, or as analytical tools or reporters in microfluidic devices or nanofluidic circuitry.

The present invention is generally directed to the synthesis and use of fluorophores. It is more specifically directed to the synthesis and use of deuterated fluorophores. In one case, the present invention provides a compound of the structure shown in FIG. 44.

The present invention is generally directed to the synthesis and use of fluorophores. It is more specifically directed to the synthesis and use of deuterated fluorophores. In one case, the present invention provides a compound of the structure shown in FIG. 44.