[Todos] Seminario DQIAQF - INQUIMAE, martes 24 de mayo - 13 hs.

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Seminario DQIAQF - INQUIMAE,  Martes 24 de Mayo - 13 hs.

Aula de Seminarios INQUIMAE - DQIAQF
Facultad de Ciencias Exactas y Naturales
Ciudad Universitaria - Pab. 2  -  Piso 3


Luisa De Cola
Physikalisches Institut, and CeNTech, University of Münster, Mendelstrasse
, D-48149 Muenster (decola en uni-muenster.de)

“LUMINESCENT SOFT AND HARD ASSEMBLIES”



Electroluminescent metal complexes have been widely investigated for their
potential use as dopant in Organig Light Emitting Devices, OLEDs, and when
charged in Light Emitting Electrochemical Cells, LEECs. In this we will
discuss the formation of soft [1,2] and hard crystalline luminescent
systems [3-5]. Tuning the design of the metal complexes based mainly on
iridium and platinum metal ions and containing phenylpyridine, pyridine,
and pyridine azoles, or dinegative tridentate N-N-N ligands we are able to
control the degree of intermolecular interactions leading to the formation
of fibers and gels, or crystalline materials. In particular the
possibility to promote aggregation and the new emission properties rising
from the formation of the assemblies, such as enhancement of the emission,
will be discussed in two examples. A non-luminescent platinum complex,
becoming extremely emitting (90% emission quantum yields) upon
aggregation, is described. The Pt(II) complex can assemble in fibers or
even form luminescent gels. The material has been used to construct
electroluminescent devices [1]. The aggregation can also be prevented and
other neutral Pt(II) complexes have been prepared and used for OLED
materials. Finally crystalline iridium complexes (left figure) will be
discussed and porous structures have been obtained with some of them. In
particular, in one of the described systems, two luminescent iridium
complexes, possessing different emission colors, and complementary charges
are employed to form complex salts and non covalent linked crystalline
porous photo- and electroactive framework [3]. The strategy described can
be extended to many photo- and electroresponsive ionic transition metal
complexes and could constitute the future generation of organometallic
zeolite-like structures. The modulation of their properties with
appropriate guests will be then discussed.

 [1]  C. A. Strassert, C.-H. Chien, M. D. Galvez Lopez, D. Kourkoulos, D.
Hertel, K. Meerholz, L. De Cola Angew. Chem. Int. Ed., 2011, 50, 946. [2] 
M. Mydlak, M. Mauro, F. Polo, M. Felicetti, J. Leonhardt, G. Diener, L. De
Cola, C.A. Strassert submitted.
[3]  M. Mauro, K. C. Schuermann, R. Prétôt, A. Hafner, P. Mercandelli, A.
Sironi, L. De Cola  Angew. Chem. Int. Ed., 2010, 49, 1222.
[4]  N. Darmawan, R. Fröhlich, L. De Cola, submitted.
[5]  E. Quartapelle Procopio, M. Mauro, M. Panigati, D. Donghi, P.
Mercandelli, A. Sironi, G. D´Alfonso, L. De Cola J. Am. Chem. Soc., 2010,
132, 14397.