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We report on the preparation and characterization of two dimensional (2D) films of (S,S,P)-1 and (R,R,M)-1ortho-oligophenylene ethylene (o-OPE) enantiomers presenting high values of circularly polarized luminescence (CPL). The amphiphilic character of these two molecules allows a precise 2D self-assembly at the air/water interface and an efficient transfer onto a glass solid support. The morphological and chiroptical characterization of the solid supports after the transfer of 1, 8, 16 and 32 Langmuir films of (S,S,P)-1 and (R,R,M)-1 has been carried out. The strong chiroptical values of these monomers allow reliable ECD measurements to be obtained after a single transfer, with ECD values increasing as the number of transferred films increases. The semi-liquid behavior of the monomers on the solid substrate allows CPL measurements free of photoselection artifacts that show values similar to those obtained in solution and independent of monomer concentration. All these properties have allowed us to develop the first simple organic molecule (SOM)-based chiroptical barcoding presenting positive and negative regions as a proof of concept.

Resumen del póster presentado a la XXXVIII Reunión Bienal de la Real Sociedad Española de Química, celebrada en el Palacio de Congresos de Granada, del 27 de junio al 30 de junio de 2022., Bone is a complex tissue in continuous process of remodeling that maintains the structural integrity of the skeleton and protects inner organs. Bone pathologies (i.e., osteoporosis) are expected to increase due to the changes in population demographics. According to WHO, the worldwide hip fracture is expected to rise to 6 million by 2050. Despite the considerable progress in conventional scaffold-based tissue engineering, the recreation of physiological complexity has remained a challenge. Self-assembled peptides and proteins have turned out to be excellent templates for the growth of inorganic minerals trying to emulate natural biomineralization processes. Herein the biomimetic mineralization of amphiphilic short-peptides was studied with the final aim of designing sophisticated inorganic/organic nanocomposites with tunable structure-function relationships. Concretely, we have developed a protocol in which the self-assembly of amphiphilic peptides and the formation of apatite nanocrystals occurs simultaneously by addition of calcium ions in such a way that the competition for Ca2+ ions modulates crystal growth in a more precise way, emulating bone mineralization. As far as we know, both processes have never been studied simultaneously for this peptide. We found that substequiometric calcium concentration provides nanocomposite materials in which nanoapatite crystals are perfectly embedded and oriented along the peptide fibers (Figure1: Influence of Ca2+ concentration on the mineralization of aromatic peptides), as observed in mineralized collagen fibrils, the basic building blocks of the complex bone structure.

Chiral stapled o-OPEs show excellent circular polarized luminescence responses (glum of 1.1 × 10–2) which can be modulated by carbophilic interactions., ortho-Oligo(phenylene)ethynylenes (o-OPEs) stapled with enantiopure 2,3-dihydroxybutane diethers have highly intense circular dichroism (CD) spectra and excellent circular polarized luminescence (CPL) responses (glum values up to 1.1 × 10–2), which are consistent with homochiral helically folded structures. In the presence of Ag(i), a change in the CPL emission is observed, representing the first example of CPL active small organic molecular emitters, which can be modulated by carbophilic interactions in a reversible manner.

We acknowledge the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (ERC-2015-STG-677023 and ERC-2013-SYG-610256 NANOCOSMOS) and the innovation program under grant agreement No. 696656 (GrapheneCore1-Graphene-based disruptive technologies) and grant agreement No. 785219 (GrapheneCore2-Graphene-based disruptive technologies) for financial support. Grants PGC2018-101181-B-I00 and MAT2017-85089-C2-1-R funded by MCIN/AEI/ 10.13039/501100011033 and “ERDF A way of making Europe” by the “European Union”, and grant PID2020-113142RB-C21 funded by MCIN/AEI/ 10.13039/501100 011033 also provided financial support. We also acknowledge Comunidad de Madrid via Programa de Investigación Tecnologías 2018 (FOTOART-CM S2018/NMT-4367), the Swiss National Science Foundation (grant number 200020-182015), the NCCR MARVEL funded by the Swiss National Science Foundation (grant number 51NF40-182892) and FEDER/Junta de Andalucía-Consejería de Economía y Conocimiento (B-FQM-428-UGR20). C. S. S. and N. R. A. acknowledge Grants RYC2018-024364-I and BES-2015-072642, respectively, funded by MCIN/AEI/ 10.13039/501100011033 and “ESF Investing in your future”. I. R. M. acknowledges the University of Granada for her postdoctoral contract (Contrato Puente-Plan Propio UGR). F.V. thanks Ministerio de Universidades for the FPU grant (FPU18/05938)., On-surface synthesis, complementary to wet chemistry, has been demonstrated to be a valid approach for the synthesis of tailored graphenic nanostructures with atomic precision. Among the different existing strategies used to tune the optoelectronic and magnetic properties of these nanostructures, the introduction of non-hexagonal rings inducing out-of-plane distortions is a promising pathway that has been scarcely explored on surfaces. Here, we demonstrate that non-hexagonal rings, in the form of tropone (cycloheptatrienone) moieties, are thermally transformed into phenyl or cyclopentadienone moieties upon an unprecedented surface-mediated retro–Buchner-type reaction involving a decarbonylation or an intramolecular rearrangement of the CO unit, respectively., Junta de Andalucía-Consejería de Economía y Conocimiento B-FQM-428-UGR20, BES-2015-072642, RYC2018-024364-I, MCIN, Ministerio de Universidades FPU18/05938, European Commission FOTOART-CM S2018/NMT-4367, European Research Council, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung 200020-182015, European Social Fund, Universidad de Granada, European Regional Development Fund 011033, PID2020-113142RB-C21, S2018/NMT-4367, National Center of Competence in Research Materials’ Revolution: Computational Design and Discovery of Novel Materials 51NF40-182892, Agencia Estatal de Investigación

This study was supported by projects RTI-2018-095794-A-C22, RYC-2016-21042 and project PID2020-118498GB-I00 funded by MCIN/AEI/10.13039/501100011033 and projects P18-FR-3533 and P18-TP-0969 by FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades (Spain). Thanks go to the CIC personnel of the University of Granada for technical assistance. MCMT acknowledges grant PRE2018-083773 funded by MCIN/AEI/10.13039/501100011033 and FSE "El FSE invierte en tu futuro", Spain. GBRR also acknowledges Junta de Andalucia for her postdoctoral contract within the PAIDI 2020 program ( DOC_01383)., Self-assembled peptides and proteins have turned out to be excellent templates for the growth of inorganic minerals and can be used to emulate natural biomineralization processes. Doing this, researchers have developed complex sophisticated materials with properties, in some cases, similar to those found in nature. Of special interest is the development of scaffolds able to guide bone regeneration. The bone tissue comprises an organic matrix composed of aligned collagen fibers containing nanoapatite crystals oriented along the fiber direction. During bone mineralization, both processes, the self-assembly of collagen fibrils and mineralization occur simultaneously. Collagen fibers are able to control calcium phosphate nucleation and subsequent apatite crystal growth at a very limited range of collagen density and ionic concentration. In this study, we reproduced the simultaneity of both processes using an artificial peptide fluorenylmethoxycarbonyl-diphenylalanine (Fmoc-FF) that has the ability to self-assemble in water after the addition of Ca2+ ions. Therefore, the peptide self-assembly process and the mineralization of apatite are Ca-demanding processes and occur simultaneously. The role of peptide and ionic concentrations has been investigated affording organic/inorganic hybrid hydrogels with different degrees of homogeneity and mineralization. Interestingly, at very low Ca2+ concentrations, we found that apatite nanocrystals are integrated into Fmoc-FF fibrils and oriented as in biologically mineralized collagen fibrils, the basic building blocks of bone., FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades (Spain) P18-FR-3533 P18-TP-0969, FSE "El FSE invierte en tu futuro", Spain, Junta de Andalucia DOC_01383; RTI-2018-095794-A-C22; RYC-2016-21042; PID2020-118498GB-I00; MCIN/AEI/10.13039/501100011033; PRE2018-083773