Phenyl pyridine-iridium metal complex compounds for organic electroluminescent device, process for preparing the compounds, and organic electroluminescent device using the compounds
The present invention relates to luminescence materials for an organic electroluminescent device (OELD), and particularly to phenyl pyridine-iridium metal complex compounds of formula (1), and preparation method thereof. In addition, the present invention relates to an organic electroluminescent device using the luminescence materials according to the present invention, which can greatly enhance the efficiency of luminescence and increase the operating life time of the device: wherein R 1 , R 2 and R 3 each are the same as defined in the specification.
1. A compound represented by the following formula (1):
wherein R 1 , R 2 and R 3 each are independently a straight or branched alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 5 to 18 carbon atoms, a substituted or un-substituted aromatic group having 5 to 18 carbon atoms, or two or more of R 1 , R 2 and R 3 taken together form an aliphatic cycle having 5 to 20 carbon atoms, or an aromatic cycle having 5 to 20 carbon atoms.
2. The compound according to claim 1 , wherein the compound is Ir-1, Ir-2, or Ir-3.
3. A preparation method of the compound of formula (1) comprising the steps of:
1) reacting the phenyl pyridine compound of formula (2) below with IrCl 3 *xH 2 O or Na 3 IrCl 6 *xH 2 O to form a precursor compound of the formula:
; and;
2) reacting the precursor compound obtained by the above step 1) with the compound of formula (3) below to obtain the compound of formula (1):
wherein R 1 , R 2 and R 3 each are the same as defined in claim 1 .
4. An organic electroluminescent device having one or more organic thin layers formed between a first electrode and a second electrode, wherein at least any one layer of the organic thin layers comprises one or more compounds represented by the formula (1) according to claim 1 or 2 .
5. The organic electroluminescent device according to claim 4 , wherein the organic thin layer comprises one or more layer selected from the group consisting of a hole transport layer, an emission layer, a hole blocking layer, an electron transport layer, and an electron injection layer.
6. The organic electroluminescent device according to claim 5 , wherein at least one or more compounds represented by the formula (1) are used as dopant of the emission layer.
7. The organic electroluminescent device according to claim 5 , wherein at least one or more compounds represented by the formula (1) are used as host of the emission layer.