The synthesis method of OXD-7 was studied chiefly.Its synthesis step as follows: 1.Ethyl 4-tert-butylbenzoate can be prepared by the esterification reaction of 4-tert-butylbenzonic acid and ethyl alcohol

then it was reacted with hydration hydrazine to get 4-(t-butyl)benzoyl hydrazine;2.m-phthaloyl chloride was prepared by the reflux reaction of isophthalic Acid and thionyl chloride;3.4-tert-butyl benzoyl hydrazine was added to the synthesized m-phthaloyl chloride.The mixture was(allowed) to react at 80℃ for 2 h

then the mixture was cooled and then poured into ice-water.The precipitate was filtered and washed with water

dry in 100℃

the previous compound of OXD-7 was prepared.Finally

the previous compound of OXD-7 was put into the three-necked bottle

POCl

3

and PCl

5

was added

heats to reflux for 5 h

the phosphorous oxychloride was removed by the distillation under a reduced pressure

filters

the residue was washed with water and recrystallized two times from ethyl alcohol to give 11.2 g of OXD-7

the purity is 97.2% by HPLC.The sublimation of OXD-7 was executed under the pressure of 35 Pa and the(temperature) of 300℃ used the sublimation system designed by ourselves.After the sublimation

the purity of OXD-7 is 99.2%

the melting point is 241.5℃.A blue organic electroluminescent device was fabricated and its structure is ITO/CuPu/NPB/OXD-7/Alq

3

/Mg-Ag/Al.An indium-tin-oxide coated glass substrate (anode substrate) was sequentially washed in a cleaning solution

rinsed in deionized water and dried.Copper phthalocyanine(150)

N

N′-bis-(1-naphthyl)-N

N′-diphenyl benzidine(600)

OXD-7

alumium-tris-8-hydroxyquinoline(350)were vapor deposited in turn on the ITO glass

then Mg-Ag alloy was vapor deposited as the anode

finally

metal aluminum was vapor deposited onto the Mg-Ag alloy as the protecting layer.The device was packaged in a dry glove box full of(nitrogen) for protection against ambient environment.The photoelectric property and life-time of OXD-7 were tested.The influence of the material purity to the lifetime and the brightness was studied and discussed.Under 8 V drive voltage

the device gives a blue emission peaked at 472 nm

the maximal brightness is about 456 cd/m

2

the CIE coordinate of the emission color is x=0.144 4

y=0.098 1.