Expanding the light absorption of poly(3-hexylthiophene) by end-functionalization with π-extended porphyrins.

Poly(3-hexylthiophene)s end-functionalized with π-extended porphyrins have been synthesized in a one-pot procedure. The polymers show a broad absorption profile extending to 700 nm and a fibrillar microstructure, which can be tuned through judicious selection of the porphyrin molar ratio

Structural and photophysical templating of conjugated polyelectrolytes with single-stranded DNA

A promising approach to influence and control the photophysical properties of conjugated polymers is directing their molecular conformation by templating. We explore here the templating effect of single-stranded DNA oligomers (ssDNAs) on cationic polythiophenes with the goal to uncover the intermolecular interactions that direct the polymer backbone conformation. We have comprehensively characterized the optical behavior and structure of the polythiophenes in conformationally distinct complexes depending on the sequence of nucleic bases and addressed the effect on the ultrafast excited-state relaxation. This, in combination with molecular dynamics simulations, allowed us a detailed atomistic-level understanding of the structure−property correlations. We find that electrostatic and other noncovalent interactions direct the assembly with the polymer, and we identify that optimal templating is achieved with (ideally 10−20) consecutive cytosine bases through numerous π-stacking interactions with the thiophene rings and side groups of the polymer, leading to a rigid assembly with ssDNA, with highly ordered chains and unique optical signatures. Our insights are an important step forward in an effective approach to structural templating and optoelectronic control of conjugated polymers and organic materials in general

Programmed Recognition between Complementary Dinucleolipids To Control the Self-Assembly of Lipidic Amphiphiles

This is the peer reviewed version of the following article: Morales‐Reina, S., Giri, C., Leclercq, M., Vela‐Gallego, S., de la Torre, I., Caston, J. R., ... & de la Escosura, A. (2020). Programmed Recognition between Complementary Dinucleolipids To Control the Self‐Assembly of Lipidic Amphiphiles. Chemistry–A European Journal, 26(5), 1082-1090, which has been published in final form at https://doi.org/10.1002/chem.201904217. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.One of the major goals in systems chemistry is to create molecular assemblies with emergent properties that are characteristic of life. An interesting approach toward this goal is based on merging different biological building blocks into synthetic systems with properties arising from the combination of their molecular components. The covalent linkage of nucleic acids (or their constituents: nucleotides, nucleosides and nucleobases) with lipids in the same hybrid molecule leads, for example, to the so-called nucleolipids. Herein, we describe nucleolipids with a very short sequence of two nucleobases per lipid, which, in combination with hydrophobic effects promoted by the lipophilic chain, allow control of the self-assembly of lipidic amphiphiles to be achieved. The present work describes a spectroscopic and microscopy study of the structural features and dynamic self-assembly of dinucleolipids that contain adenine or thymine moieties, either pure or in mixtures. This approach leads to different self-assembled nanostructures, which include spherical, rectangular and fibrillar assemblies, as a function of the sequence of nucleobases and chiral effects of the nucleolipids involved. We also show evidence that the resulting architectures can encapsulate hydrophobic molecules, revealing their potential as drug delivery vehicles or as compartments to host interesting chemistries in their interior.Research in Madrid received support from the Spanish Ministry of Economy and Competitivity (MINECO: CTQ‐2014‐53673‐P, CTQ‐2017‐89539‐P, and EUIN2017‐87022). This work was also supported in part by grants to JRC from MINECO (BFU2017‐88736‐R), and Comunidad Autónoma de Madrid (P2018/NMT‐4389). A.d.l.E. and M.S. thank the interdisciplinary framework provided by the European COST Action CM1304 (“Emergence and evolution of complex chemical systems”). A.d.l.E. and C.G. acknowledge the “Programme for Post‐Doctoral Talent Attraction to CEI UAM+CSIC—Intertalentum” (GA 713366). Research in Mons was supported by the Wallonia Region and the Fund for Scientific Research (FNRS, Belgium) under the grants MIS No. F.4532.16 (SHERPA) and EOS No. 30650939 (PRECISION). Confocal fluorescence microscopy was performed with the help of Sylvia Gutierrez Erlandsson, from the Advanced Light Microscopy Service of Centro Nacional de Biotecnologia (CNB). The professional editing service NB Revisions was used for technical preparation of the text prior to submission

Solvent Molding of Organic Morphologies Made of Supramolecular Chiral Polymers

12sihe self-assembly and self-organization behavior of uracil-conjugated enantiopure (R)- or (S)-1,1'-binaphthyl-2,2'-diol (BINOL) and a hydrophobic oligo(p-phenylene ethynylene) (OPE) chromophore exposing 2,6-di(acetylamino)pyridine termini are reported. Systematic spectroscopic (UVvis, CD, fluorescence, NMR, and SAXS) and microscopic studies (TEM and AFM) showed that BINOL and OPE compounds undergo triple H-bonding recognition, generating different organic nanostructures in solution. Depending on the solvophobic properties of the liquid media (toluene, CHCl3, CHCl3/CHX, and CHX/THF), spherical, rod-like, fibrous, and helical morphologies were obtained, with the latter being the only nanostructures expressing chirality at the microscopic level. SAXS analysis combined with molecular modeling simulations showed that the helical superstructures are composed of dimeric double-cable tape-like structures that, in turn, are supercoiled at the microscale. This behavior is interpreted as a consequence of an interplay among the degree of association of the H-bonded recognition, the vapor pressure of the solvent, and the solvophobic/solvophilic character of the supramolecular adducts in the different solutions under static and dynamic conditions, namely solvent evaporation conditions at room temperature.partially_openopenĐorđević, Luka; Marangoni, Tomas; Miletić, Tanja; Rubio-Magnieto, Jenifer; Mohanraj, John; Amenitsch, Heinz; Pasini, Dario; Liaros, Nikos; Couris, Stelios; Armaroli, Nicola; Surin, Mathieu; Bonifazi, DavideĐorđević, Luka; Marangoni, Tomas; Miletic, Tanja; Rubio Magnieto, Jenifer; Mohanraj, John; Amenitsch, Heinz; Pasini, Dario; Liaros, Nikos; Couris, Stelios; Armaroli, Nicola; Surin, Mathieu; Bonifazi, David

Structural and Spectroscopic Properties of Assemblies of Self-Replicating Peptide Macrocycles

Self-replication at the molecular level is often seen as essential to the early origins of life. Recently a mechanism of self-replication has been discovered in which replicator self-assembly drives the process. We have studied one of the examples of such self-assembling self-replicating molecules to a high level of structural detail using a combination of computational and spectroscopic techniques. Molecular Dynamics simulations of self-assembled stacks of peptide-derived replicators provide insights into the structural characteristics of the system and serve as the basis for semiempirical calculations of the UV-vis, circular dichroism (CD) and infrared (IR) absorption spectra that reflect the chiral organization and peptide secondary structure of the stacks. Two proposed structural models are tested by comparing calculated spectra to experimental data from electron microscopy, CD and IR spectroscopy, resulting in a better insight into the specific supramolecular interactions that lead to self-replication. Specifically, we find a cooperative self-assembly process in which β-sheet formation leads to well-organized structures, while also the aromatic core of the macrocycles plays an important role in the stability of the resulting fibers

From Interaction to Function in DNA‐Templated Supramolecular Self‐Assemblies

International audienceDNA-templated self-assembly represents a rich and growing subset of supramolecular chemistry where functional self-assemblies are programmed in a versatile manner using nucleic acids as readily-available and readily-tunable templates. In this review, we summarize the different DNA recognition modes and the basic supramolecular interactions at play in this context. We discuss the recent results that report the DNA-templated self-assembly of small molecules into complex yet precise nanoarrays, going from 1D to 3D architectures. Finally, we show their emerging functions as photonic/electronic nanowires, sensors, gene delivery vectors, and supramolecular catalysts, and their growing applications in a wide range of area from materials to biological sciences

Teaching photosensitizers a new trick: red light-triggered G-quadruplex alkylation by ligand co-localization

We propose a bimolecular approach for G-quadruplex alkylation, using a pro-reactive furan-containing ligand, activated by red-light irradiation of a proximate G4-binding photosensitizer. G4- over dsDNA alkylation can be achieved selectively and proves high-yielding at low ligand excess. HPLC and modelling studies allowed identifying potential residues involved in the alkylation

Self-assembled hybrid hydrogels based on an amphipathic low molecular weight peptide derivative and a water-soluble poly(para-phenylene vinylene)

The self-assembly of an amphipathic low molecular weight peptide and a water-soluble p-conjugated polyelectrolyte is studied in order to form hybrid hydrogel materials with synergistic properties. The self-assembly of the complex yields a network of one-dimensional fibrils, with enhanced fluorescence of the p-conjugated polyelectrolyte in the hydrogel form. These hybrid hydrogels are also tested to study the kinetics of release of a molecular dye.The authors thank the Cost Action CM 1304 (Emergence and Evolution of Complex Chemical Systems) for a Short Term Scientic Missions (STSM) of M. T.-S. in Mons. Research in Mons is supported by the Science Policy Office of the Belgian Federal Government (BELSPO – PAI 7/05). This work was also supported by the Fonds de la Recherche Scientique – FNRS under the under the grants n 1.B333.15F (CHIRNATES) and n F.4532.16 (MIS-SHERPA). J. R.-M. is FNRS post-doctoral researcher and M. S. is FNRS research associate. This work was also supported by the Ministry of Economy and Competitiveness of Spain (Grant CTQ2012-37735) and Universitat Jaume I (Grant P1-1B2013-57). M. T.-S. thanks the Ministry of Education, Culture and Sport of Spain for an FPU fellowship

DNA electronic circular dichroism on the inter-base pair scale:An experimental-theoretical case study of the at homo-oligonucleotide

A successful elucidation of the near-ultraviolet electronic circular dichroism spectrum of a short double-stranded DNA is reported. Time-dependent density functional theory methods are shown to accurately predict spectra and assign bands on the microscopic base-pair scale, a finding that opens the field for using circular dichroism spectroscopy as a sensitive nanoscale probe of DNA to reveal its complex interactions with the environment

Self-assembly and chiroptical properties in supramolecular complexes of adenosine phosphates and guanidinium-bispyrene

International audienc