Aluminum chelate complex for organic EL material
View Patent ↗This invention provides an organic EL material useful for the emissive layer of an organic EL element which deteriorates little in luminance when operated over a prolonged period of time and shows excellent durability. The material is an aluminum chelate complex which is represented by general formula (1) in which Ar 1 is a mono- or bicylic arylene group, Ar 2 is a mono- or bicyclic aryl group, R 1 -R 6 are hydrogen or hydrocarbon groups containing 1-8 carbon atoms and contains a compound represented by general formula (1) in which Ar 2 is a halogen as an impurity in an amount of 350 wt ppm or less.
1. A method for preparing an aluminum chelate complex for an organic EL element represented by general formula (1) which contains less than 350 wt ppm of a compound represented by general formula (2) as an impurity:
in general formulas (1) and (2), Ar 1 is naphthylene, Ar 2 is naphthyl or phenyl, the total number of aromatic rings in Ar 1 and Ar 2 is 3 to 4 and these aromatic rings may be condensed; R 1 -R 6 are independently hydrogen or hydrocarbon groups containing 1-8 carbon atoms; and X is Br, Cl or I, said method comprising:
reacting aluminum isopropoxide successively with a quinolinol derivative and a phenolic compound represented by HO—Ar 1 —Ar 2 which comprises purifying the quinolinol derivative and the phenolic compound in such a manner as to reduce the amount of a compound contained therein and represented by HO—Ar 1 —X to 350 wt ppm or less and then submitting them to the reaction.
2. A method for preparing an aluminum chelate complex for an organic EL element represented by general formula (1) which contains less than 350 wt ppm of a compound represented by general formula (2) as an impurity:
in general formulas (1) and (2), Ar 1 is a bicyclic arylene group, Ar 2 is a mono- or bicyclic aryl group, the total number of aromatic rings in Ar 1 and Ar 2 is 3 to 4 and these aromatic rings may be condensed; R 1 -R 6 are independently hydrogen or hydrocarbon groups containing 1-8 carbon atoms; and X is a halogen, said method comprising:
reacting aluminum isopropoxide successively with a quinolinol derivative and a phenolic compound represented by HO—Ar 1 —Ar 2 which comprises purifying the quinolinol derivative and the phenolic compound in such a manner as to reduce the amount of a compound contained therein and represented by HO—Ar 1 —X to 350 wt ppm or less and then submitting them to the reaction.
3. A method for preparing an aluminum chelate complex for an organic EL element represented by general formula (1) which contains less than 350 wt ppm of a compound represented by general formula (2) as an impurity:
in general formulas (1) and (2), Ar 1 is a bicyclic arylene group, Ar 2 is a mono- or bicyclic aryl group, the total number of aromatic rings in Ar 1 and Ar 2 is 3 to 4 and these aromatic rings may be condensed; R 1 -R 6 are independently hydrogen or hydrocarbon groups containing 1-8 carbon atoms; and X is a halogen, said method comprising:
reacting aluminum isopropoxide successively with a quinolinol derivative and a phenolic compound represented by HO—Ar 1 —Ar 2 which comprises purifying by sublimation the crude aluminum chelate complex containing 350 wt ppm or more of a compound represented by general formula (2) after washing with or recrystallization from an organic solvent until the amount of said halogen-containing compound becomes 350 wt ppm or less.
4. A method for preparing an aluminum chelate complex as described in claim 2 which comprises reacting a compound represented by HO—Ar 1 —X with a compound represented by (Ar 2 )a-Y (wherein Y is Cu, X, Li, B(OH) 2 , MgX, ZnX and SnMe 3 , X is a halogen and a is an integer of 1-10) to form the phenolic compound represented by HO—Ar 1 —Ar 2 .
5. A method for preparing an aluminum chelate complex as described in claim 4 which comprises purifying by recrystallization the phenolic compound obtained by the reaction and represented by HO—Ar 1 —Ar 2 and purifying by sublimation the aluminum chelate complex obtained from said phenolic compound.
6. A method for preparing an aluminum chelate complex as described in claim 3 which comprises reacting a compound represented by HO—Ar 1 —X with a compound represented by (Ar 2 )a-Y (wherein Y is Cu, X, Li, B(OH) 2 , MgX, ZnX and SnMe 3 , X is a halogen and a is an integer of 1-10) to form the phenolic compound represented by HO—Ar 1 —Ar 2 .
7. A method for preparing an aluminum chelate complex as described in claim 6 which comprises purifying by recrystallization the phenolic compound obtained by the reaction and represented by HO—Ar 1 —Ar 2 and purifying by sublimation the aluminum chelate complex obtained from said phenolic compound.