The fluorescence of the concentrated solutions of N-vinylcarbazole and the structure of the second excimer sites of poly-N-vinylcarbazole

The emission properties of N-vinylcarbazole have been investigated. Fluid solutions were observed covering a broad range of concentration to exhibit the structureless excimer emission bands at energies approximately 2 200 cm−1 and 4 100 cm−1 to the red of the 355 nm emission band of the monomer fluorescence of dilute solution. In high concentration range (1M) N-vinylcarbazole shows broad fluorescence composed of three components. The broad emission at the longer wavelength (λ max=415 nm) is assigned to the sandwich-like excimer fluorescence and the interesting, new emission in the short-wavelength region (λ max=385 nm) is assigned to the second excimer fluorescence in analogy to poly-N-vinylcarbazole.