Luminescent labels based on aromatic and heterocyclic compounds, including reactive intermediates used to synthesize these compounds, and methods of synthesizing and using these reporter compounds. These labels combine high photostabilities, large Stokes' shifts and contain a pyrimidinium moiety as a water-soluble group. These luminescent compounds relate generally to the following structure: The methods relate generally to the synthesis and/or use of reporter compounds for fluorescence lifetime or fluorescence polarization based applications.