Spirobifluorenyl indole derivatives, preparation method and applications thereof

The invention discloses spirobifluorenyl indole derivatives, a preparation method and applications thereof. The provided spirobifluorenyl indole derivatives can be used a multifunctional organic luminescent material. Spirobifluorenyl indole is taken as the core, due to the steric-hindrance effect of spirobifluorenyl indole, twisting in molecules is realized; the electron clouds of the highest occupied orbit and the lowest empty orbit of a molecule can be relatively separated to obtain a very small singlet-triplet state energy level difference, thus a luminescent molecule with a thermally induced delayed fluorescent property can be designed and prepared; the synthesis is relatively simple; the thermal properties, luminescent efficiency and light color of materials can be adjusted, even deep blue light can be obtained; the high fluorescent quantum efficiency can be realized, the derivatives can be taken as the fluorescent object and can also be taken as the host material of fluorescence and phosphorescence by u