New fluorescent phenothiazine carboxylates for fluorescent nanomaterials

Fluorescent electrospun polymers doped with new 10-ethyl-10H-phenothiazine-3-carboxylate derivatives were prepared, and their optical properties were investigated. The fluorescence emission properties were studied in solution and solid state for 10-ethyl-10H-phenothiazine-3-carboxylic acid (2) and for two if its salts (3a, b). The quantum yields and fluorescence lifetimes were also determined for 10-ethyl-10H-phenothiazine-3-carboxylates before and after incorporation in polymeric matrices. From fluorescence emission in solid state and in solution, large Stokes shifts were recorded in all investigated solvents for the salts 3a, b.