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A new luminescent azaindole derivative has been designed and synthesized to be implemented in a light-emitting device. The molecular geometry and frontier orbital energy have been investigated by using density functional theory. This newly synthesized molecule emits strongly both in solution and solid state. The fluorescence emission in THF upon addition of an increasing amount of HO has been measured also, displaying an increase of the fluorescence signal which is associated with an aggregation-induced emission phenomenon. Double-layer light-emitting devices including an active layer of the novel emissive material were successfully fabricated. The red-shift of the electroluminescence spectra with respect to the photoluminiscence emission was attributed to the presence of different types of complexes in the emissive material (EM) layer, which are preferentially formed between the nearest-neighbor hole-electron pairs of the electron injection and the EM layers (electroplex)., This work was financially supported by the Ministry of Economy and Competitiveness of Spain through Projects CTQ2013-40562-R and CTQ2014-56422-P. C.M. thanks the Research Foundation-Flanders for her postdoctoral fellowship. G.d.M. thanks the Ministry of Economy and Competitiveness for a “Ramón y Cajal” contract (RYC-2013-12772). The authors are also indebted to Belspo program through IAP VI/27 and VII/05 and to the KULeuven Research Fund through GOA 2011/3 and C14/15/053. The authors gratefully acknowledge financial support from the European Union’s Seventh Framework Programme FP7/2007-2013 under Grant Agreement No. 310651 SACS.

A new kind of low molecular-mass organic gelator (LMOG) π-electron-deficient N,N-octyl-7,7′-diazaisoindigo (1) with aggregation-induced enhanced emission (AIEE) phenomenon is described. This organogel is capable of self-assembling through intermolecular H-bonding and π-π interactions between diazaisoindigo molecules. Its rheological properties, X-ray diffraction pattern, optical properties and theoretical calculations were investigated. The AIEE effect is exhibited in fluorescence during the formation of the supramolecular organogel, which persisted in the xerogel state, and the spectral red-shifts suggest the formation of J-type aggregates during the gelation process via π-π interactions in microbelts or 3D networks. Fluorescence lifetime and quantum yield significantly increase from dilute solution to the aggregate state. From a theoretical perspective, the effect of the aggregation of 1 on the photophysical properties was also studied by means of the density functional theory (DFT). In this sense, the lowest energy electronic transitions were calculated for both the single molecule and different size aggregates in order to predict spectral shifts. In addition, the geometry and molecular properties of the excited state were analyzed in different material states., This work was financially supported by the MICINN of Spain (Grant CTQ2013-40562-R), by Consejería de Economia y Conocimiento, Junta de Andalucía (Grant FQM-337), Consejería de Educación y Ciencia de la Junta de Comunidades de Castilla-La Mancha (Project PEII11-0279-8538), and Diputación de Albacete (DIPUAB-16-GARZONRUIZ). The authors thank Centro de Servicios de Informática y Redes de Comunicaciones (CSIRC), Universidad de Granada (Spain),and Servicio de Supercomputación de la Universidad de Castilla-La Mancha for providing the omputing time. J.P. thanks Dr. M. Ramírez for his help in the PXRD pattern representation and interpretation and E. Rodríguez and P. Ciriafor their support. The authors thank Prof. J. Reimers, University of Technology Sydney, for allowing us to use the DUSHIN program.

The p-type semiconducting properties of a triphenylene-fused triindole mesogen, have been studied by applying two complementary methods which have different alignment requirements. The attachment of only three flexible alkyl chains to the nitrogen atoms of this π-extended core is sufficient to induce columnar mesomorphism. High hole mobility values (0.65 cm V s) have been estimated by space-charge limited current (SCLC) measurements in a diode-like structure which are easily prepared from the melt, rendering this material a good candidate for OPVs and OLEDs devices. The mobility predicted theoretically via a hole-hopping mechanism is in very good agreement with the experimental values determined at the SCLC regime. On the other hand the hole mobility determined on solution processed thin film transistors (OFETs) is significantly lower, which can be rationalized by the high tendency of these large molecules to align on surfaces with their extended π-conjugated core parallel to the substrate as demonstrated by SERS. Despite the differences obtained with the two methods, the acceptable performance found on OFETs fabricated by simple drop-casting processing of such an enlarged aromatic core is remarkable and suggests facile hopping between neighboring molecular columns owing to the large conducting/isolating ratio found in this discotic compound.

et al., We report the synthesis, mesomorphic behavior, and mobility values of a series of highly ordered N-substituted triindole-based columnar liquid crystals. Shortening the length of N-alkylic substituents from N-dodecyl to N-methyl chains results in a drastic approach of the disks within the columns and in an impressive increase in charge carrier mobility. An study of aggregation in solution provide insights into the intermolecular forces responsible of the reduction of the intrastack distance as the size of the N-alkyl chains is decreased and offer evidence of stabilization of the columns by the contribution of cooperative CH−π interactions. The materials presented here exhibit mobility values, even in totally misaligned columnar phases, that may compete with those of the best polycrystalline organic semiconductors, without the need of costly vacuum evaporation processes., Support by Comunidad Autónoma de Madrid under project S2009/MAT-1756 and by Ministerio de Ciencia e Innovación (Spain) under projects CTQ2010-18813, CTQ2009-09030/BQU, MAT2011-27978-C02-01 are gratefully acknowledged.