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Tuning the electronics of nanotubes: Electron-accepting 11,11,12,12-tetracyano-9,10-anthraquinodimethane (TCAQ) nanotweezers endowed with a carboxylic acid-containing dendrimeric moiety form exceptionally stable n-/p-type dispersions with single-walled carbon nanotubes (SWCNTs) in water. Upon photoexcitation, the nanohybrids undergo a less common electron transfer from the SWCNTs to the TCAQ nanotweezers., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

Fully substituted peptide/[60]fullerene hexakis-adducts offer an excellent opportunity for multivalent protein recognition. In contrast to monofunctionalized fullerene hybrids, peptide/[60]fullerene hexakis-adducts display multiple copies of a peptide in close spatial proximity and in the three dimensions of space. High affinity peptide binders for almost any target can be currently identified by in vitro evolution techniques, often providing synthetically simpler alternatives to natural ligands. However, despite the potential of peptide/[60]fullerene hexakis-adducts, these promising conjugates have not been reported to date. Here we present a synthetic strategy for the construction of 3D multivalent hybrids that are able to bind with high affinity the E-selectin. The here synthesized fully substituted peptide/[60]fullerene hybrids and their multivalent recognition of natural receptors constitute a proof of principle for their future application as functional biocompatible materials., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

AbstractWe report on the synthesis and characterization of atomically precise one‐dimensional diradical peripentacene polymers on a Au(111) surface. By means of high‐resolution scanning probe microscopy complemented by theoretical simulations, we provide evidence of their magnetic properties, which arise from the presence of two unpaired spins at their termini. Additionally, we probe a transition of their magnetic properties related to the length of the polymer. Peripentacene dimers exhibit an antiferromagnetic (S=0) singlet ground state. They are characterized by singlet–triplet spin‐flip inelastic excitations with an effective exchange coupling (Jeff) of 2.5 meV, whereas trimers and longer peripentacene polymers reveal a paramagnetic nature and feature Kondo fingerprints at each terminus due to the unpaired spin. Our work provides access to the precise fabrication of polymers featuring diradical character which are potentially useful in carbon‐based optoelectronics and spintronics., Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

CRUE-CSIC (Acuerdos Transformativos 2022), Scholl oxidation has become an essential reaction in the bottom-up synthesis of molecular nanographenes. Herein, we describe a Scholl reaction controlled by the electronic effects on the starting substrate (1 a, b). Anthracene-based polyphenylenes lead to spironanographenes under Scholl conditions. In contrast, an electron-deficient anthracene substrate affords a helically arranged molecular nanographene formed by two orthogonal dibenzo[fg,ij]phenanthro-[9,10,1,2,3-pqrst]pentaphene (DBPP) moieties linked through an octafluoroanthracene core. Density Functional Theory (DFT) calculations predict that electronic effects control either the first formation of spirocycles and subsequent Scholl reaction to form spironanographene 2, or the expected dehydrogenation reaction leading solely to the helical nanographene 3. The crystal structures of four of the new spiro compounds (syn 2, syn 9, anti 9 and syn 10) were solved by single crystal X-ray diffraction. The photophysical properties of the new molecular nanographene 3 reveal a remarkable dual fluorescent emission., Ministerio de Ciencia, Innovación y Universidades (España), Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

CRUE-CSIC (Acuerdos Transformativos 2021), Ministerio de Ciencia e Innovación (MICINN), Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub

CRUE-CSIC (Acuerdos Transformativos 2021), Suitably engineered molecular systems exhibiting triplet excited states with very long lifetimes are important for high-end applications in nonlinear optics, photocatalysis, or biomedicine. We report the finding of an ultra-long-lived triplet state with a mean lifetime of 93 ms in an aqueous phase at room temperature, measured for a globular tridecafullerene with a highly compact glycodendrimeric structure. A series of three tridecafullerenes bearing different glycodendrons and spacers to the C60 units have been synthesized and characterized. UV/Vis spectra and DLS experiments confirm their aggregation in water. Steady-state and time-resolved fluorescence experiments suggest a different degree of inner solvation of the multifullerenes depending on their molecular design. Efficient quenching of the triplet states by O2 but not by waterborne azide anions has been observed. Molecular modelling reveals dissimilar access of the aqueous phase to the internal structure of the tridecafullerenes, differently shielded by the glycodendrimeric shell., Ministerio de Economía y Competitividad (MINECO), Centro de Excelencia Severo Ochoa, Generalitat de Catalunya, European Social Funds and the SUR del DEC de la Generalitat de Catalunya, Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub