Organic ionic functional materials

Abstract

The present invention relates to a novel non-polymeric organic ionic compound comprising one ion having a functional organic group, such as a matrix group, a hole injection group, a hole transport group, an electron injection group and an electron transport group, and comprising another ion preferably being so small that it may act as a mobile ion in films containing the organic ionic compound. Furthermore, the present invention relates to a composition containing the novel organic ionic compound and another functional compound. The novel organic ionic compound or the composition may be used in organic devices as functional materials, such as matrix materials or for materials charge transport. The resulting organic devices are also object of the present invention.

Claims

1. A composition comprising a non-polymeric organic ionic compound having the following Formula (1):
(M).sup.+/(N).sup./+Formula (1), wherein the symbols have the following meanings: M is a mono-charged organic anionic compound comprising a functional group acting as a matrix group, a hole injection group, a hole transport group, an electron injection group or an electron transport group; N is an alkali or an alkaline earth metal group, wherein M and N are counter ions, and a functional organic compound selected from the group consisting of a matrix material, a fluorescent or phosphorescent emitter, a dye, a hole injection material, a hole transport material, an electron injection material and an electron transport material.

2. The composition according to claim 1, wherein the function of the functional organic group of M is different from the function of the functional organic compound.

3. The composition according to claim 1, further comprising a matrix compound and a fluorescent or phosphorescent emitter compound.

4. The composition according to claim 1, further comprising an ion conductor compound.

5. The composition according to claim 1, further comprising a matrix compound and a dye.

6. An electronic device comprising the composition according to claim 1.

7. The device according to claim 6, wherein the device is an organic light emitting diode, a polymer light emitting diode, an organic light emitting transistor, an organic light emitting electrochemical cell, an organic light emitting electrochemical transistor, an organic field effect transistor, a thin film transistor, an organic solar cell, an organic laser diode, an organic integrated circuit, a radio frequency identification tag, a photodetector, sensor, a logic circuit, a memory element, a capacitor, a charge injection layer, a Schottky diode, a planarizing layer, an antistatic film, a conducting substrate or a pattern, a photoconductor, an electrophotographic element, an organic solar concentrator, an organic spintronic device, or an organic plasmon emitting device.

8. The device according to claim 6, wherein the device is an organic light emitting electrochemical cell or an organic solar cell.

9. The device according to claim 6, wherein the device is for use for phototherapy in medicine.

10. The device according to claim 6, wherein the device is for use phototherapy in the field of cosmetics.

11. The composition according to claim 1, wherein M is selected from the group consisting of arylamine, styrylamine, fluorescein, perynone, phthaloperynone, naphthaloperynone, diphenylbutadiene, tetraphenylbutadiene, cyclopentadienes, tetraphenylcyclopentadiene, pentaphenylcyclopentadiene, coumarine, oxadiazole, bisbenzoxazoline, oxazone, pyridine, pyrazine, imine, benzothiazole, benz-oxazole, benzimidazole, aldazines, stilbene, styrylarylene derivatives, distyrylarylene derivatives, diphenylethylene, vinylanthracene, diaminocarbazole, pyran, thiopyran, diketopyrrolopyrrole, mellocyanine, acridone, quinacridone, and cinnamic acid esters.

12. The composition according to claim 1, wherein M is an anion of formula (28) to (42), (64) to (93), (116) to (124) or (148)-(153) ##STR00078## ##STR00079## ##STR00080## ##STR00081## ##STR00082## ##STR00083## ##STR00084## ##STR00085## ##STR00086## ##STR00087## wherein X is CR or N, and R can be the same or different in each occurrence and is selected from H, CN, linear and branched alkyl rest with 1 to 20 C-atoms, linear or branched alkenyl radical with 2 to 20 C-atoms and one or more non conjugated double bonds, linear or branched alkinyl rest with 2 to 20 C-atoms and one or more non conjugated triple bonds, partly or completely non saturated cycloalkyl rest with 3 to 7 C-atoms which can be substituted with alkyl rests with 1 to 6 C-atoms, saturated and partly or completely non saturated heteroaryls, heteroaryl-C.sub.1-C.sub.6-alkyl, or alkyl-C.sub.1-C.sub.6-alkyl, wherein different R together can form a ring, wherein one or more of the substituents R can partly or completely be substituted with halogen, particularly with F and/or Cl, and OR, CN, C(O)OH, C(O)NR.sub.2, SO.sub.2NR.sub.2, C(O)Y, SO.sub.2OH, SO.sub.2Y, NO.sub.2, wherein the substituents R are not substituted with halogen at the same time, wherein one or two carbon atoms of the substituents R, which are non adjacent or bound to an heteroatom, can be substituted by a group selected from O, S, S(O), SO.sub.2, N.sup.+R.sub.2, C(O)NR, SO.sub.2NR, and P(O)R wherein RH, unsubstituted, partly or completely with F substituted alkyl with 1 to 6 C-atoms, cycloalkyl with 3 to 7 C-atoms, unsubstituted or substituted phenyl and Y=halogen.

Description

WORKING EXAMPLES

Example 1

(1) Materials

(2) TEG1 is a triplet green emitter, which can be synthesized according to WO 2004/026886.

(3) ##STR00070##

(4) TMM1 is a triplet matrix material, which can be synthesized according to WO 2005/053055.

(5) ##STR00071##

(6) TMM2 is wide-gap material, used as triplet co-matrix material, which can be synthesized according to WO 2009/124627.

(7) ##STR00072##

(8) Poly(ethylene oxide) (PEO) is used as ion conducting material. PEO having a viscosity average molecular weight Mv=110.sup.6 can be purchased from Aldrich, and is used as received.

(9) The first ionic material IM1, lithium trifluoromethanesulfonate (LiCF.sub.3SO.sub.3), can be purchased from Aldrich, and is used as received and as reference.

(10) ##STR00073##

(11) The second ionic material IM2 is a new ionic compound according to the present invention, and can be synthesized as follows.

Example 2

(12) Synthesis IM2

(13) 1. Preparation of Aryl Arenesulfonyl Chloride:

(14) ##STR00074##

(15) A solution of thionyl chloride (20 ml, 274 mmol) in dry DMF (0.16 ml) is added to 2-phenylbenzimidazole-5-sulfonic acid (5 g, 20 mmol) (CAS 27503-81-7). The resulting composition is stirred at 60 C. for 3.5 h. The solution is poured into ice. The aqueous solution is extracted (dichloromethane), dried, and concentrated to give crude 2-phenylbenzimidazole-5-sulfonyl chloride (5.27 g, 98%) as an oil.

(16) 2. Preparation of Aryl Arenesulfonates:

(17) ##STR00075##

(18) To a solution of phenol (1.6 g, 17 mmol) in dichloromethane (30 ml) and 7 ml of triethylamine, 2-phenylbenzimidazole-5-sulfonyl chloride (5 g, 17 mmol) is added portionwise at room temperature. After stirring overnight, 25 ml of water is added to the composition and the composition is stirred for 2 h at 650. The composition is extracted with ethyl acetate (200 ml) and the organic layer is washed with water (150 ml), three times with 10% aqueous HCl (150 ml), two times with water (150 ml), two times with saturated aqueous NaHCO.sub.3, and two times with brine (100 ml). The resulting product is then dried over Na.sub.2SO.sub.4. The solvent is evaporated under vacuum. Flash chromatography on silica gel (hexane:ethyl acetate 80:20) yields the aryl arenesulfonates (88%).

(19) 3. Preparation of IM2:

(20) ##STR00076##

(21) 2-phenyl-3H-benzoimidazole-5-sulfonic acid phenyl ester (0.79 g, 2 mmol) is dissolved in 40 cm.sup.3 of ethanol and LiOH (0.048 g, 2 mmol) dissolved in 1 cm.sup.3 of water is added. The compound is re-crystallised in acetone. A white powder can be obtained by evaporation of the solvent and isolated by vacuum filtration. Yield 74%.

Example 3

(22) Quantum Chemical Calculations on IM2 and its Precursor

(23) Quantum simulations on organic neutral compounds are conducted employing Gaussian 03 W software (Gaussian Inc.). For organic compound comprising no metal, at first a semi-empirical method, Ground State/Semi-empirical/Default Spin/AM1 (Charge 0/Spin Singlet) is used to optimise the molecular geometry, and then the energy is calculated by TD-DFT (time-dependent density functional theory) method TD-SCF/DFT/Default Spin/B3PW91 with the basis set 6-31G(d) (Charge 0/Spin Singlet). For metal complexes comprising transition metals (incl. lanthanide and actinide), the geometry optimisation is conducted using Hartree-Fock with Basis Set LanL2 MB; and the energy calculation is then conducted by using TD-DFT with correction functional B3PW91 and basis set 6-31G(d) for non-metal elements and Lanz2DZ (Los Alamos National Laboratory 2-double-z) for transition metals. A couple of data can be obtained by such calculations but one of the most important results provided by quantum chemical calculations in this field include HOMO/LUMO energy levels (highest occupied molecular orbital/lowest unoccupied molecular orbital), band gaps and energies for triplet and singlet excited states. Hereby, the first triplet (T1) and first singlet (S1) excited states are most important. From the energy calculation one gets HOMO HEh and LUMO LEh in Hartree units. And the HOMO and LUMO values in electron volts (eV) is determined with following equations, which can be derived from the calibration using Cyclovoltametry (CV) measurements.
HOMO(eV)=((HEh*27.212)0.9899)/1.1206
LUMO(eV)=((LEh*27.212)2.0041)/1.385

(24) These values will be used as HOMO-LUMO levels of the compounds in the present invention. As an example, for TMM1 (see also Table 1) a HOMO of 0.21292 Hartree and a LUMO of 0.06843 Hartree can be calculated, which corresponds to a calibrated HOMO of 6.05 eV, and a calibrated LUMO of 2.79 eV, respectively.

(25) Instead of IM2, the precursor of IM2, Pre-IM2 is calculated.

(26) TABLE-US-00001 TABLE 1 Summary of energy levels of TMM1, TMM2, TEG1 and Pre-IM2 Homo Corr. Lumo Corr. Singulett Triplett T1 Material [eV] [eV] S1 [eV] [eV] TMM1 6.05 2.79 3.48 2.70 TMM2 6.17 2.28 3.09 2.93 TEG1 5.33 2.41 2.91 2.68 Pre-IM2 6.43 2.96 3.67 2.93

(27) Energy levels of TMM1, TMM2, TEG1 and Per-IM2 are summarized in Table 1. TMM1 and TMM2 both have a T1 higher that TEG1. Pre-IM2 has a T1 of 2.93 eV, which is suitable as a triplet matrix for TEG1, and a LUMO of 2.96 eV, which is good for electron transport. One skilled in the art will expect that IM2 has very similar electronic properties as Pre-IM2. Thus IM2 corresponds to an organic compound of Formula (1), wherein M comprises an electron transport group and/or matrix group.

Example 4

(28) Solution 1 and 2

(29) Two different solutions (formulations) comprising ionic compounds according to the invention (IM2) and reference (IM1) are prepared employing standard techniques known to the person skilled in the art. 1. Preparation of a composition according the Table 2; 2. Preparation of a solution 1 and 2 by dissolving the corresponding (see Table 2) composition in a mixed solvent of cyclohexanone and DMF in weight ratio of 1:1 with a concentration of 23 mg/ml; 3. Stirring the solutions in a glove box for 3 h; 4. The solutions are filtered employing Millipore Millex LS, Hydrophobic PTFE 5.0 m.

(30) Both solutions can then be used to build an emissive layer in an electroluminescent device by coating, or to get mixed powders by evaporating the solvents for further use.

(31) TABLE-US-00002 TABLE 2 Solutions with a concentration of 23 mg/ml Composition for EML [wt %] Solution1 TMM1(25%):TMM2(25%):TEG1(12%):IM1(15%):PEO(23%) Solution2 TMM1(25%):TMM2(25%):TEG1(12%):IM2(15%):PEO(23%)

Example 5

(32) Preparation of OLEC1 and OLEC2

(33) OLEC1 using IM1, and OLEC2 using IM2 in the emissive layer, in a sandwiched structure anode/PEDOT/Interlayer/EML/Cathode, are prepared according to the following steps: 1. PDEOT (Baytron P AI 4083) is deposited with a thickness of 80 nm onto ITO glass substrate (Technoprint Inc.) by spin coating and then heated for 10 min. at 120 C. in a clean room; 2. 20 nm Interlayer is deposited by spin coating from a toluene solution of HIL-012 (Merck KGaA) having a concentration of 0.5 wt %, and then heated at 180 C. for 60 min in a glove box; 3. The emissive layer is deposited by spin-coating the solution according to Example 4 yielding a layer with a thickness of 160 nm in the glove box; 4. The device is heated at 50 C. for 30 min. and then put in vacuum for 30 min to remove residual solvent; 5. An Al (150 nm) cathode is deposited by evaporation onto the emissive layer; 6. The device is encapsulated using a UV-cured resin, UV Resin T-470/UR7114 (Nagase Chemtex Corporation), and a glass cap.

Example 6

(34) Characterisation of OLEC1 and OLEC2

(35) OLEC1 and OLEC2 are then characterized by employing standard techniques well known to one skilled in the art. The following properties are recorded: VIL characteristics, EL spectrum and color coordinates, efficiency, driving voltages.

(36) The performance of OLECs is summarized in the Table 3, wherein Uon stands for turn-on voltage, and U(100) for the voltage at 100 nits.

(37) TABLE-US-00003 TABLE 3 Max. Eff. Uon U (100) CIE x CIE y OLEC1 4.3 5.5 8.4 0.36 0.60 OLEC2 8.2 4.4 7.0 0.35 0.61

(38) Both OLEC shows similar color coordinates (CIE), but compared to OLEC1 using the reference ionic compound IM1, OLEC2 using a new ionic compound according to the present invention shows a much improved performance, in aspects of efficiency and driving voltage.

(39) Further improvement in performance can be achieved by different ways, for example by optimization of the concentration in the EML, the thickness of the EML and/or interlayer, and particularly by further exploiting the materials and the corresponding device disclosed in the present invention.