Publication: SÍNTESIS Y CARACTERIZACIÓN DE NUEVOS COMPLEJOS CATIÓNICOS Y ANIÓNICOS DE Ir (III) CON POTENCIALES APLICACIONES EN DISPOSITIVOS EMISIORES DE LUZ, LEC
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Date
2017-07
Authors
SALAS CLAVIJO, FELIPE ANDRÉS
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Abstract
Dentro de los diferentes tipos de dispositivos de iluminación que existen en la
actualidad, como los LED (Ligth Emitting Diode) y OLED (Organic Ligth Emitting
Diode), existe un dispositivo que aún se encuentra en desarrollo, llamado LEC
(Ligth-Emitting Electrochemical Cells). Estos dispositivos contienen como material
luminiscente un complejo de metal de transición iónico (iTMC: ionic Transition
Metal Complex), siendo los complejos de Ir(III) los más destacados. Manipulando
el gap HOMO-LUMO (HOMO: Highest Occupied Molecular Orbital y LUMO:
Lowest Unoccupied Molecular Orbital) de estos complejos, es posible modificar la
energía de emisión, y por ende, el color del dispositivo fabricado a partir de un Ir-
iTMC. Con el objetivo de generar nuevas especies de Ir(III) que presenten
emisiones a lo largo de todo el espectro visible, y que sean de mayor estabilidad
(disminución de efectos de auto-apagamiento), en el presente trabajo de Tesis, se
realizó la síntesis y caracterización fotofísica de una nueva serie de
complejos catiónicos de Ir(III) utilizando ligandos ciclometalados del tipo: F2ppy
= 2-(2,4’-difluorofenil)piridina y bzq = benzoquinolina. Los ligandos ancilares
utilizados fueron: neo = neocuproína, biq = 2,2’-biquinolina y dabiq = ácido [2,2'-
biquinolina]-4,4'-dicarboxílico. Entonces, se obtuvo una familia de seis complejos
catiónicos conformada por: C1: [Ir(F2ppy)2(neo)]+, C2: [Ir(F2ppy)2(biq)]+, C3:
[Ir(F2ppy)2(dabiq)]+, C4: [Ir(bzq)2(neo)]+, C5: [Ir(bzq)2(biq)]+ y C6: [Ir(bzq)2(dabiq)]+.
Con esta serie de complejos, se logró observar que de acuerdo a las naturalezas
electrónicas de ligandos, los complejos presentan emisiones que abarcan todo el
espectro visible, yendo desde el color azul hasta el color rojo. La utilización de
ligandos ancilares que generan una especie de jaula para los centros metálicos,
proveen el incremento de la estabilidad, evitando los efectos de auto-apagamiento,
y de esta manera prometen largos tiempos de vida de los dispositivos LEC.
En este trabajo de Tesis, también se propuso realizar la síntesis y
caracterización fotofísica de una nueva serie de complejos aniónicos de
Ir(III), utilizando como ligando ciclometalado ppy (ppy = 2-fenilpiridina), y ligandos
ancilares del tipo O^O, específicamente: sal = ácido 2-hidroxibezóico, CF3sal = ácido 2-hidroxi-4-(trifluorometil)benzoico y bd = 3-(carboxypredicentrina),para
obtener una familia de tres complejos aniónicos del tipo: A1: [Ir(ppy)2(sal)]-, A2:
[Ir(ppy)2(CF3sal)]- y A3: [Ir(ppy)2(bd)]-. En la síntesis de los complejos A1 y A2, se
presentaron problemas respecto a la caracterización estructural. Sin embargo, se
realizó un completo estudio teórico de las propiedades electrónicas y fotofísicas
para A1-A3, mostrando excelentes características de estos complejos para futuras
aplicaciones en dispositivos LEC. Por consiguiente, es importante profundizar en
la mejora de las condiciones experimentales que permitan obtener estos
complejos, con el fin de contribuir con una nueva serie de especies luminiscentes
que involucran el uso de ligandos de la naturaleza.
Among the different types of lighting devices that exist today, such as LED (Light Emitting Diode) and OLED (Organic Light Emitting Diode), there is a device that is still under research, called LEC (Ligth-Emitting Electrochemical Cells). These devices are manufacturing with luminescent material that correspond to ionic transition metal complexes (iTMC), where, the Ir(III) complexes are highlights. By manipulating the HOMO-LUMO gap (HOMO: Highest Occupied Molecular Orbital and LUMO: Lowest Unoccupied Molecular Orbital) of these complexes, it is possible to modify the emission energy, and hence the emission color of the device from an Ir-iTMC. With the aim to obtain new Ir(III) complexes that will exhibit emissions across the range of the visible spectrum, and they have a great stability (auto-quenching processes diminished), in the present Thesis project, it was perform the synthesis and photophysical characterization of a new series of Ir(III) cationic complexes using as ciclometalating ligands: F2ppy = 2- (2,4'- difluorophenyl) pyridine and bzq = benzoquinoline. The ancillary ligands used were: neo = neocuproine, biq = 2,2'-biquinoline and dabiq = [2,2'-biquinoline] -4,4'- dicarboxylic acid. Therefore, a family of six cationic complexes was obtained: C1: [Ir(F2ppy)2(neo)]+, C2: [Ir(F2ppy)2(biq)]+, C3: [Ir(F2ppy)2(bzq)]+, C4: [Ir(bzq)2(neo)]+, C5: [Ir(bzq)2(biq)]+ and C6: [Ir(bzq)2(dabiq)]+. With this series of complexes, it was possible to observe that according with the electronic nature of the ligands, the complexes show emissions that cover the entire visible spectrum, going from the blue color to the red color. The use of “cage-type” ancillary ligands of the metal centers provides a stability increase, avoiding the auto-quenching processes in order to promise a long lifetime of the LEC devices. In this work of Thesis, also it was propose to perform of the synthesis and photophysical characterization of a new series of Ir(III) anionic complexes using ppy (ppy = 2-phenylpyridine) as cyclometalating ligand, and sal = benzoic acid, CF3sal = (2-hydroxy-4-(trifluoromethyl) benzoic acid and bd = 3- (carboxypredicentrine). in order to obtain a family of three anionic complexes of the type: A1: [Ir(ppy)2(sal)]-, A2: [Ir(ppy)2(CF3sal)]- and A3: [Ir(ppy)2(bd)]-. In the synthesis and the structural characterization of A1 and A2 there were some problems. In spite of this, a complete theoretical study of the electronic and photophysical properties of A1-A3 was carried out, which showed excellent characteristics of these complexes for future applications in LEC devices. Therefore, it is important deepen in the enhanced of the experimental conditions that allow us to obtain these complexes, in order to contribute with a new series of luminescent materials that involve the use of nature ligands.
Among the different types of lighting devices that exist today, such as LED (Light Emitting Diode) and OLED (Organic Light Emitting Diode), there is a device that is still under research, called LEC (Ligth-Emitting Electrochemical Cells). These devices are manufacturing with luminescent material that correspond to ionic transition metal complexes (iTMC), where, the Ir(III) complexes are highlights. By manipulating the HOMO-LUMO gap (HOMO: Highest Occupied Molecular Orbital and LUMO: Lowest Unoccupied Molecular Orbital) of these complexes, it is possible to modify the emission energy, and hence the emission color of the device from an Ir-iTMC. With the aim to obtain new Ir(III) complexes that will exhibit emissions across the range of the visible spectrum, and they have a great stability (auto-quenching processes diminished), in the present Thesis project, it was perform the synthesis and photophysical characterization of a new series of Ir(III) cationic complexes using as ciclometalating ligands: F2ppy = 2- (2,4'- difluorophenyl) pyridine and bzq = benzoquinoline. The ancillary ligands used were: neo = neocuproine, biq = 2,2'-biquinoline and dabiq = [2,2'-biquinoline] -4,4'- dicarboxylic acid. Therefore, a family of six cationic complexes was obtained: C1: [Ir(F2ppy)2(neo)]+, C2: [Ir(F2ppy)2(biq)]+, C3: [Ir(F2ppy)2(bzq)]+, C4: [Ir(bzq)2(neo)]+, C5: [Ir(bzq)2(biq)]+ and C6: [Ir(bzq)2(dabiq)]+. With this series of complexes, it was possible to observe that according with the electronic nature of the ligands, the complexes show emissions that cover the entire visible spectrum, going from the blue color to the red color. The use of “cage-type” ancillary ligands of the metal centers provides a stability increase, avoiding the auto-quenching processes in order to promise a long lifetime of the LEC devices. In this work of Thesis, also it was propose to perform of the synthesis and photophysical characterization of a new series of Ir(III) anionic complexes using ppy (ppy = 2-phenylpyridine) as cyclometalating ligand, and sal = benzoic acid, CF3sal = (2-hydroxy-4-(trifluoromethyl) benzoic acid and bd = 3- (carboxypredicentrine). in order to obtain a family of three anionic complexes of the type: A1: [Ir(ppy)2(sal)]-, A2: [Ir(ppy)2(CF3sal)]- and A3: [Ir(ppy)2(bd)]-. In the synthesis and the structural characterization of A1 and A2 there were some problems. In spite of this, a complete theoretical study of the electronic and photophysical properties of A1-A3 was carried out, which showed excellent characteristics of these complexes for future applications in LEC devices. Therefore, it is important deepen in the enhanced of the experimental conditions that allow us to obtain these complexes, in order to contribute with a new series of luminescent materials that involve the use of nature ligands.
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DISPOSITIVOS LEC