Study On The Synthesis And Properties Of Diphenoquinone Electronic Transporting Materials

Diphenoquinone is a kind of important electron transport material, which has stable electron transport performance, excellent photosensitive, lower dark potential decline, good durability and repeatability. However, its poor solubility and compatibility with resins restrict its practical application. Simultaneously, because of the immature synthesis technology, higher yield and large-scale production of this kind of compound has not been achieved. In this paper, the synthesis process of 3,5-dimethyl-3',5'-diter-butyl-4,4'-diphenoquinone and 3-chloro-3',5,5'-tritertbutyl- 4,4'-diphenoquinone was developed, and the amplified synthesis of 3,3',5,5'- tetramethyl-4,4'-diphenoquinon was studied. The photoconductive property analysis and comparision of the synthesized materials were also involved.The infuences of the factors, such as feeding method, reaction time, reaction temperature and materials ratio, on the oxidative coupling of 2,6-dimethyl phenol and 2,6-ditertbutyl phenol to prepare 3,5-dimethyl-3',5'-di-ter-butyl-4,4'-diphenoquinone were studied. In the optimimum synthesis process, the raw materials are mixed in chloroform and dropped to reactor in 2h, the reaction temperature and time was controlled at 50℃and 4h respectively, and the molar ratio of potassium permanganate to the two reactants is 8:1:1. The yield and purity of the product was 48.99% and 99.53% respectively.2-chloro-2',6,6'-tritertbutyl-4,4'-biphenol was prepared from 3,3',5,5'-tetratert- butyl-4,4'-diphenoquinone via detertbutylation and chlorination reaction. And then, 3-chloro-3',5,5'-tritertbutyl-4,4'-diphenoquinone was obtained after the oxidation of 2-chloro-2',6,6'-tritertbutyl-4,4'-biphenol. The optimum condition of detertbutylation and chlorination s that HCl gas is accessed under a nitrogen atmosphere, the amount of carbon tetrachloride solvent is 25mL/g raw material, the molar ratio of aluminum chloride and reactant is 0.77:1, the reaction time is 10h and the reaction temperature is 15~20℃. The optimum condition of oxidation reaction is that the amount of chloroform solvent is 50mL/g raw material, the molar ratio of lead dioxide oxidant to reactants is 20:1, the reaction temperature is 50℃, and the reaction time is 3h. The yield of two reactions was 62.47% and 84.02%. And the HPLC purity of the two products was 90.80% and 99.13%. The structure of products are confirmed by melting point, IR, MS and 1H-NMR analysis.The synthesis of 3,3',5,5'-tetramethyl diphenoquinone using 2,6-ditertbutyl phenol as raw material, was amplified. In 1L flask, 0.30 mole of raw material was oxidized by 1.5 mole potassium permanganate in 0.45L of chloroform at 55℃for 8h. The yield and purity of the product was 90.78% and 99.42% respectively, and thepreparation scale is each batch of 32.68g. Photoconductive properties of 3,5-dimethyl-3',5'-ditertbutyl-4,4'-dipheno- quinone, 3-chloro-3',5,5'-tritertbutyl-4,4'-diphenoquinone, 3,3',5,5'-tetramethyl-4,4'- diphennoquinone, and 3,3',5,5'-tetratertbutyl-4,4'-diphenoquinone were studied and compared. The results showed that 3,5-dimethyl-3',5'-ditertbutyl-4,4'-diphenoqui- none and 3-chloro-3',5,5'-tritertbuyl-4,4'-diphenoquinone have good compatibility with the resin, higher recharge potential, lower residual potential and good photosensitivity.