Synthesis And Properties Of Derivatives Of Spirobifluorene

In the field of photoelectric display, the research and applications of organic and organic/inorganic hybrid optoelectronic materials and devices made significant progress and development. Organic light-emitting diodes (OLEDs) have received more and more attention by virtue of the following properties:direct current driving, self-luminous, small volume, fast response, full color emission, wide view angle and simple manufacture techniques.Recently, spirobifluorene have great significance in the field of OLED. According to the non-planar structure of spirofluorene, the previous research has focused on the modify of 2,2',7,7'-location. With these modification, morphologic and thermal stability have been greatly improved. However, the improvements of luminous performance have not met people's expectation. In order to regulate the transporting performance or improve the photophysical properties of material and device, one of the methods is to introduce functional groups which possess light performance or thermal stability to optimize the structure of the materials.As OLED materials, drendrimers are branched macromolecules, which possess many advantages for the special structure and easily adjustability.Based on spirobifluorene and combined advantage of dendrimers, two spirobifluorene derivatives A1 with carbazole electron donating group and A2 with cyano electron withdrawing group were synthesized.A1 and A2 exhibit good solubility in common organic solvents and are suitable for wet methods such as spin coating to make thin films.Furthermore, the degradation temperature are 535℃and 575℃respectively.All the results show that they have excellent thermal stability.Redox properties of A1 and A2 were studied with cyclic voltammetry. Additionally, LUMO energy level, HOMO energy level and Eg were calculated with absorption edge technology.These data show that A1 and A2 have the charge transporting properties and are expected to be used for OLED in the future.