Synthesis And Application Of Indolo [3,2-B] Carbazole Compounds

As a new generation of flat panel display technology, organic light-emitting diodes (OLEDs) has unparalleled advantages over traditional display technologies, including low-voltage driving, high luminous efficiency, short response time, good temperature characteristics, low production cost, excellent flexibility and plasticity, and large visual angle and so on. Especially, in the new century, sustained and rapid development of information technology puts forward higher request to information displayed system, and the OLEDs with great advantage have gained enormous attention in the scientific community and the business community.In the past few decades, with the purpose of improving the efficiency and stability of the OLEDs, many efforts have been made to develop various novel organic materials with desirable properties, and many materials have been used to fabricate display. However, there still exist many enormous challenges, such as production of large-screen display, improvement of efficiency and service life of OLEDs.At present, the OLEDs are almost multilayer devices, consisting of light emitting layer, hole-transporting layer, electron-transporting layer and electrodes et al. Anyway, the degree of recombination of the electron and hole in the light emitting layer determines the performance of OLEDs devices, so it is very necessary to design and develop the high performance materials with light emitting, hole-transporting and electron-transporting properties for the OLEDs. Based on the above reason, we became interested in incorporating the indolo[3,2-b]carbazole moiety and the dimesitylboron moiety into a single molecule to obtain novel materials with excellent luminescent, hole-transporting and electron-transporting properties.Indolo[3,2-b]carbazole (ICZ) and its derivatives have received much attention due to their large planar and rigid conjugated structures, strong intermolecular charge transfer, high fluorescence quantum yields together with their remarkable photophysical properties. So they are always used to be as the photoelectric building materials. And many ICZ derivatives with outstanding properties such as better morphological stability and thermal durability as well as desirable charge-injecting and transporting properties have been reported during the past few decades.Boron-containing π-conjugated compounds have emerged during the past decade. They have high fluorescence quantum yields owing to the overlap between the vacant p-orbital of the boron center and the conjugated moieties, which make these compounds a promising class of candidates for optoelectronic materials. Generally, for the application of organoboron compounds in optoelectronic materials and devices, the boron center must resist nucleophilic attack and hydrolysis. Researchers have readily achieved this by functionalizing the boron center with bulky aryl substituents. Thus, triarylboron compounds containing a dimesitylboron group and/or several dimesitylboron groups have been successfully developed as materials for nonlinear optics and anion sensing and utilized as emitting and/or electron-transporting materials for OLEDs.In this paper, we will discuss the synthesis, photophysical properties, theoretical study, and the electroluminescent and charge-transporting properties of the compounds.