White light and colour-tunable emission from a single component europium-1,8-naphthalimide thin film

The synthesis and fabrication of spin coated films of a new Eu³⁺ complex [Eu(1)₃] derived from the 1,8-naphthalimide containing ligand 1H is presented. The complex is multi-emissive displaying blue emission from the 1,8-naphthalimide fluorophore and red emission from the Eu³⁺ centre in both solution-state and solid-state. This allows the overall emission to be tuned by changing the excitaton wavelength, where varing degrees of red and blue emission intensity alter the overall emission colour from blue, to red and including white-light emission. The complex was spin-coated onto quartz slides giving 134 nm thick coatings that retained the multi-emissive and colour tunable properties. Overall, resulting in a colour-tunable system which in solution, solid, and thin film states can alter the overall colour from deep red to dark blue.