Design and synthesis of regioisomerically pure unsymmetrical xanthene derivatives for staining live cells and their photochemical properties.

We have demonstrated the synthesis of regioisomerically pure unsymmetrical xanthene derivatives consisting of three units which can be independently modified to control their physical properties. The photochemical properties of the synthetic unsymmetrical xanthene derivatives were investigated in solution by UV-vis absorption and fluorescence measurements, and their cell imaging properties were examined by confocal laser-scanning microscopy.