Cyclic Triindoles and Tetraindoles: Substituent and Symmetry Effects on their Structural and Electronic Characteristics

During the last decade heptacyclic 10,15-dihydro-5H-diindolo[3,2-a:3',2'-c]carbazole (triindole) has been extensively studied as a new π-conjugated platform in the construction of self-assembling materials for optoelectronics. Specially remarkably is the record hole mobility values determined on triindole liquid crystals.1 In order to facilitate the design of new materials on a molecular basis and establish clear guidelines to fine tuning electronic parameters, we have recently synthesized new triindole and tetraindole-based systems.2-3 Our joint experimental and theoretical investigation shows that N-substitution, symmetry lowering of the platform, and insertion of π-spacers in extended dimers strongly impact on the fundamental electronic properties of triindoles.2 In addition, saddle-shaped tetraindoles are found to be an interesting 3D rigid scaffold to obtain electroactive molecules with increased dimensionality.3 We hope that this study can not only advance useful structure-property relationships of conjugated indole-based systems but also guide the design of new materials with potential applications in organic electronics.References 1. E.M. García-Frutos, U.K. Pandey, R. Termine, A. Omenat, J. Barberá, J.L. Serrano, A. Golemme, B. Gómez-Lor, Angew. Chem. Int. Ed. 2011, 50, 7399 2. a) C. Ruiz, J.T. López Navarrete, M.C.Ruiz Delgado, B. Gómez-Lor, Org. Lett. 2015, 17, 2258−2261. b) C. Ruiz, E.M. García-Frutos, D.A. da Silva Filho, J.T. López Navarrete, M.C. Ruiz Delgado, and B. Gómez-Lor, J. Phys. Chem. C 2014, 118, 5470−5477 3. C. Ruiz, A. Monge, E. Gutiérrez-Puebla, I. Alkorta, J. Elguero, J. T. López Navarrete, M.C. Ruiz Delgado and B. Gómez-Lor, submittedUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Theoretical study of Covalent Organic Frameworks based on C3-symmetric Central Cores

In recent years, the design and synthesis of COFs (covalent organic frameworks) has been deeply investigated. These materials are constructed from the union of different covalently linked conjugated platforms and they have a wide range of analytical applications, such as adsorption and / or separation of certain compounds, catalysis or identification of analytes, among others.1 On the other hand, the π-conjugated nature of these systems together with their extended 3D nature make them excellent candidates to be used in organic electronics.2 Recently, in collaboration with the group of Dr. Berta Gómez-Lor, we have studied the electronic and optical properties of four new porous truxene-based polymers.3 The results of this work opens the door to the control of the degree of π-conjugation and therefore to the optoelectronic properties of these materials (i.e., their potential as nitroaromatic compound sensors) through the substitution position of the truxene units. Here we propose to expand this study to COFs (Figure 1) derived from platforms with C3 symmetry based not only on truxene (X=C) but also on triindole (X=N) and truxenone (X=CO) units by means of periodic DFT-calculations (see Figure 1). Specifically, we study how the different structural modifications affect the intra- and intermolecular properties of the systems for their subsequent synthesis and real application in organic electronic devices.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

A theoretical investigation of the diradical character and cyclophane formation in π-conjugated diradicals.

π-Conjugated diradical compounds which feature unpaired electrons in the ground state are essential for understanding the nature of chemical bonds and have potential applications in material science1. In fact, an important research effort by our group has been directed towards carbazole-based diradicaloids2, aiming to explore how external stimuli impacts on supramolecular organization, and thus on the resulting optical and electronic properties. Thanks to this research, we have demonstrated that these materials are potential building blocks for dynamic covalent chemistry (DCC)3. In our present work, we wanted to explore beyond carbazole-based diradicals and analyse what would be the diradical character after modification of the chemical structure of the carbazole skeleton. For this purpose, we will analyse the structural and electronic properties of carbazole-based diradicals after the following chemical modifications: (i) heteroatom substitution, (ii) core elongation and (iii) insertion of donor/acceptor groups. In addition, the effect of the heteroatom substitution on the dynamic interconversion between the monomer and cyclophane aggregates will be also investigated.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Sonochemical Synthesis of Optically Tuneable Conjugated Polymer Nanoparticles

The development of novel and simple methodologies for the obtaining of semiconductive polymer nanoparticles with fine-tuned optical properties represents nowadays a challenging research area as it involves a simultaneous chemical modification and nanostructuration of the polymer. Here, starting from poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], this objective is achieved with the one-pot synthesis of oligomers with tunable conjugation length and their nanostructuration, employing a miniemulsion method. Ultrasound irradiation of heterogeneous mixtures leads to the formation of hypochlorous acid that disrupts the electronic conjugation through polymer chain cleavage. Moreover, control over the degree of the electronic conjugation of the oligomers, and therefore of the optical properties, is achieved simply by varying the polymer concentration of the initial solution. Finally, the presence of surfactants during the sonication allows for the formation of nanoparticles with progressive spectral shift of the main absorption (from λ = 476 to 306 nm) and emission bands (from λ = 597 to 481 nm). The integration of conducting polymer nanoparticles into polymeric matrices yields self-standing and flexible fluorescent films

Theoretical study of the electronic and charge transport properties of Coronoid Carbazole-based Macrocycles

Carbazole (Cz) units have been recognized as crucial conjugated cores in organic electronics due to their good electro- and photoactive properties compared to other heterocycles.1 Furthermore, conjugated macrocycles should be useful building blocks for the construction of 2D porous surface networks or 3D inclusion complexes among other supramolecular structures.2 One of the most interesting features of conjugated cyclic oligomers is that their electronic, structural, and optical properties can be tuned as a function of their interior and exterior domains. Therefore, a systematic study of conjugated macrocycles with well-defined diameters has crucial importance to establish structure-property relationships of these materials. For that purpose, we carried out a purely theoretical study of coronoid molecules based on three different indolocarbazoles (ICz) structural isomers (see Figure 1) as indolo[2,3-a]carbazole (23a-4MC), indolo[2,3-b]carbazole (23b-4MC) and indolo[3,2-b]carbazole (32b-4MC). This work aims to identify new macrostructures with interesting electronic properties as well as to display the usefulness of the theoretical tools to advance knowledge in the organic electronics fieldUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Computational study of coronoid carbazole based Macrocycles: influence of isomerism.

Carbazole (Cz) units have been recognized as crucial conjugated cores in organic electronics due to their good electro- and photoactive properties, such as high hole-transporting mobilities, when compared to other heterocycles. On the other hand, conjugated macrocycles should be useful building blocks for the construction of 2D porous surface networks or 3D inclusion complexes among other supramolecular structures.2 One of the most interesting features of conjugated cyclic oligomers is that their electronic, structural, and optical properties can be tuned as a function of their interior and exterior domains. Therefore, a systematic study of conjugated macrocycles with well-defined diameters is of crucial importance to establish the structure-property relationships of these materials. For that purpose, we carried out a purely theoretical study of coronoid molecules based on three different indolocarbazoles (ICz) structural isomers (see Figure 1) as indolo[2,3-a]carbazole (23a-4MC), indolo[2,3-b]carbazole (23b-4MC) and indolo[3,2-b]carbazole (32b-4MC), which contain four indolecarbazole units (4MC). This work aims to identify new macrostructures with interesting electronic properties as well as to display the usefulness of the theoretical tools to advance knowledge in the organic electronics field. Overall, this investigation contributes to elucidating the electronic properties of coronoid macrocycles, guiding experimental chemists to produce new molecules with desirable properties.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Use of Alternative Wood for the Ageing of Brandy de Jerez

The use of alternative types of wood has arisen for the aging of the Brandy de Jerez, on a pilot plant level. In particular, besides the use of American oak, two more types of oak have been studied, French oak and Spanish oak, allowed by the Technical File for the ID Brandy de Jerez, and chestnut, which, though it is not officially allowed, is a type of wood which had been traditionally used in the area for the aging of wines and distillates. All of them have been studied with different toasting levels: Intense toasting and medium toasting. The study of the total phenolic composition (TPI), chromatic characteristics, organic acids, and sensory analysis have proven that chestnut leads to distillates with a higher amount of phenolic compounds and coloring intensity than oak. This behavior is the opposite as regards the toasting of the wood. Among the different types of oak, Spanish oak produces aged distillates with a higher phenolic composition and a higher color intensity. Regarding tasting, the best-assessed samples were those aged with chestnut, French oak, and American oak, and the assessors preferred those who had used a medium toasting level to those with an intense leve

Analysis of morphologic effects of polymeric semiconducting materials by Raman spectroscopy.

The organic electronics research field has greatly advanced in the last decades, already rendering materials able to compete with their inorganic counterparts. However, the final blossoming of this field is expected to come with the complete understanding and control of the charge transport parameters in organic materials. In polymeric semiconductors, tuning the film morphology and crystallinity has been found to be crucial for efficient charge transport in devices. In this sense, planar backbones with locked conformations induced by intramolecular interactions are good candidates for high performing polymers. Thus, being able to elucidate both ordered and disordered phases in semiconducting films has been proven to be of great interest. Raman spectroscopy is a rapid, noninvasive technique able to gather information on molecular and supramolecular levels, thus being really useful for this purpose. In this communication, optical spectroscopies and, in particular Raman spectroscopy, are used to analyze the impact of the gradual fluorination on the electronic properties of donor-acceptor polymers, demonstrating that the final performance is highly dependent on the building blocks in with the fluorine atoms are introduced.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Donor-acceptor truxene-based porous polymers: synthesis, optoelectronic characterization and defense-related applications

Funding for open Access charge: Universidad de Málaga / CBUA. This research was funded by MICINN/AEI/ 10.13039/501100011033 (project PID2022-139548NB-I00, PID2019-104125RB-I00, and PID2020-112590GB-C22) and by Junta de Andalucía (P09FQM-4708 and P18-FR-4559). N.M.-G. and S.G.-V. contributed equally to this work. The authors would like to thank the computer resources, technical expertise and assistance provided by the SCBI (Supercomputing and Bioinformatics) center and the vibrational spectroscopy (EVI) lab of the Research Central Services (SCAI) of the University of MálagaFour donor-acceptor (D-A) polymers are synthesized by combining two different electron donors (truxene and its more electron rich triaza analogue, triindole) with an electron-deficient monomer (benzothiadiazole) through two different positions (2,7,13 or 3,8,13) and their optoelectronic properties are studied by theoretical and experimental methods. One of the polymers exhibits remarkable sensing capabilities for explosive nitraoaromatics while another demonstrated efficient photocatalytic activity in the aerobic sulfoxidation of the sulfur mustard simulant 2-chloro-ethyl ethyl sulfide (MGS) sulfoxidation. These results highlight their potential applications in defense-related areas. Moreover, the structure-performance relationships observed among the four polymers have enabled us to deepen the understanding of the mechanisms underlying the performance of these polymers in the aforementioned applications, thereby providing valuable insights to further improve their properties

Insertion of a Spin Crossover FeIII Complex into an Oxalate-Based Layered Material: Coexistence of Spin Canting and Spin Crossover in a Hybrid Magnet

This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in Inorganic Chemistry, copyright © 2008 American Chemical Society. To access the final edited and published work see https://doi.org/10.1021/ic801165bThe syntheses, structures, and magnetic properties of the compounds of formula [FeIII(sal2trien)]2[MnII2(ox)3]·4H2O·C3H7NO (1) and [InIII(sal2trien)]2[MnII2(ox)3]·3H2O·CH3OH (2) are reported. The structure presents a homometallic 2D honeycomb anionic layer formed by MnII ions linked through oxalate ligands and a cationic double layer of [Fe(sal2trien)]+ or [In(sal2trien)]+ complexes intercalated between the 2D oxalate network. The magnetic properties and Mössbauer spectroscopy of 1 indicate the coexistence of a magnetic ordering of the Mn(II) oxalate network that behaves as a weak ferromagnet and a gradual spin crossover of the intercalated [Fe(sal2trien)]+ complexes.Financial support from the European Union (NoE MAGMANet, MERG-CT-2004-508033), the Spanish Ministerio de Educación y Ciencia (Project Consolider-Ingenio in Molecular Nanoscience, CSD2007-00010, and projects CTQ2005-09385-C03 and MAT2007-61584), and the Generalitat Valenciana are gratefully acknowledged. The authors also thank J. M. Martínez-Agudo and Prof. C. J. Gómez-García, University of Valencia, for assistance with the magnetic characterization and Prof. J. F. Létard and Dr. C. Desplanches, ICMCB, CNRS, Université Bordeaux 1, for the magnetic characterization under light irradiation.S