China
Africa
Explore chapters and articles related to this topic
A Method for the Preparation of Pyromellitic Acid from Durene via Liquid Phase Oxidation
Published in John R. Kosak, Thomas A. Johnson, Catalysis of Organic Reactions, 2020
Durene is obtained from complex mixtures of aromatics from oil-refining processes (“reformate gasoline”) or from cracking processes in olefin manufacture (“pyrolysis gasoline”) [1]. More recently the methanol to gasoline process, which went on-stream in New Zealand in 1986, has been found to produce large quantities of durene as a by-product. It is estimated that as much as 60 million pounds of durene may be isolated from this source [2].
Recent progress on exciplex-emitting OLEDs
Published in Journal of Information Display, 2019
A significant feature of exciplexes is their photoluminescence (PL) spectra. As the fraction of CT in the exciplex increase, the PL spectra of exciplexes are redshifted from the PL spectra of the constituent molecules, broad, and featureless without the vibrational progression [9,13]. One example is shown in Figure 1b, where exciplexes are formed between 9,10-dicyanoanthracene (DCA) and various alkylbenzenes such as p-xylene, 1,2,4-trimethylbenzene, 1,2,3,5-tetramethylbenzene, durene, pentamethylbenzene, and hexamethylbenzene in cyclohexane [9]. DCA and the alkylbenzens are the electron acceptor and electron donors, respectively. The average degrees of CT of each exciplex-forming systems are also given in Figure 1(b). Exciplexes participating in emission have various degrees of CT which are dependent on the microscopic environment and librational displacement. The simulated PL spectra (red curves) of exciplexes are well matched with the experimental ones (black curves). The decrease of the oxidation potentials of the donors corresponding to the increase of the energy levels of the HOMO of the donors leads to the decrease of the energy of the pure CT state. It gives rise to the increase of the average degree of CT of exciplexes, resulting in the reduction of the characteristics from the pure LE state, and the expansion of the characteristics from the pure CT state.