Real space demonstration of induced crystalline 3D nanostructuration of organic layers

La filiació de Marcos Paradinas Aranjuelo en el moment de la publicació és l'Institut Català de Nanociència i NanotecnologiaThe controlled 3D nanostructuration of molecular layers of the semiconducting molecules CH (pentacene) and N,N'-dioctyl-3,4,9,10-perylene tetracarboxylic diimide (PTCDI-C8) is addressed. A tip-assisted method using atomic force microscopy (AFM) is developed for removing part of the organic material and relocating it in up to six layer thick nanostructures. Moreover, unconventional molecular scale imaging combining diverse friction force microscopy modes reveals the stacking sequence of the piled layers. In particular, we unambiguously achieve epitaxial growth, an issue of fundamental importance in thin film strategies for the nanostructuration of more efficient organic nanodevices

Influence of the relative molecular orientation on interfacial charge-transfer Excitons at donor/acceptor Nanoscale heterojunctions

We address the impact of the relative orientation between donor (D) and acceptor (A) molecules at the D/A heterojunction on the exciton dissociation. For this purpose, two-dimensional heterojunctions of diindenoperylene (DIP) and N,N'-dioctyl-3,4,9,10-perylene tetracarboxylicdiimide (PTCDI-C) deposited onto SiO/Si are grown, which exemplify two model interfaces with the π-staking direction either perpendicular or parallel to the interface. Aspects related to the morphology of the heterojunctions and charge photogeneration are studied by scanning probe force methods and photoluminescence (PL) spectroscopy. Results from PL spectroscopy indicate that the exciton dissociation is influenced by the different relative molecular orientations of A and D. For the configuration with stronger orbital overlap between A and D at the interface, the exciton dissociation is dominated by recombination from an interfacial charge-transfer state. © 2014 American Chemical Society

Compelling DNA intercalation through ‘anion– anion’ anti-coulombic interactions: boron cluster self-vehicles as promising anticancer agents

Anticancer drugs inhibit DNA replication by intercalating between DNA base pairs, forming covalent bonds with nucleotide bases, or binding to the DNA groove. To develop safer drugs, novel molecular structures with alternative binding mechanisms are essential. Stable boron hydrides offer a promising alternative for cancer therapy, opening up additional options like boron neutron capture therapy based on 10B and thermal neutron beams or proton boron fusion therapy using 11B and proton beams. These therapies are more efficient when the boron compound is ideally located inside cancer cells, particularly in the nucleus. Current cancer treatments often utilize small, polycyclic, aromatic, planar molecules that intercalate between ds-DNA base pairs, requiring only a spacing of approximately 0.34 nm. In this paper, we demonstrate another type of intercalation. Notably, [3,3′-Fe(1,2-C2B9H11)2]−, ([o-FESAN]−), a compact 3D molecule measuring 1.1 nm × 0.6 nm, can as well intercalate by strong non-bonding interactions preferentially with guanine. Unlike known intercalators, which are positive or neutral, [o-FESAN]− is a negative species and when an [o-FESAN]− molecule approaches the negatively charged DNA phosphate chain an anion–anion interaction consistently anti-electrostatic via Ccluster–H⋯O–P bonds occurs. Then, when more molecules approach, an elongated outstandingly self-assembled structure of [o-FESAN]−–[o-FESAN]− forms moving anions towards the interthread region to interact with base pairs and form aggregates of four [o-FESAN]− anions per base pair. These aggregates, in this environment, are generated by Ccluster–H⋯O–C, N–H⋯H–B and Ccluster–H⋯H–B interactions. The ferrabis(dicarbollide) boron-rich small molecules not only effectively penetrate the nucleus but also intercalate with ds-DNA, making them promising for cancer treatment. This amphiphilic anionic molecule, used as a carrier-free drug, can enhance radiotherapy in a multimodal perspective, providing healthcare professionals with improved tools for cancer treatment. This work demonstrates these findings with a plethora of techniquesAuthors received support from the Spanish Ministerio de Economía y Competitividad (PID2020-116728RB-I00, PID2022-136802NB-I00, RED2022-134120-T and TED2021-129738B-I00), the Generalitat de Catalunya (2017SGR1720). L. Gutiérrez Gálvez was supported by FPU19/06309 grant from the Spanish Ministry of Universities. S. Y. was supported by the China Scholarship Council (CSC) under Grant No. 202006990034

Microfluidic pneumatic cages : A novel approach for in-chip crystal trapping, manipulation and controlled chemical treatment

The precise localization and controlled chemical treatment of structures on a surface are significant challenges for common laboratory technologies. Herein, we introduce a microfluidic-based technology, employing a double-layer microfluidic device, which can trap and localize in situ and ex situ synthesized structures on microfluidic channel surfaces. Crucially, we show how such a device can be used to conduct controlled chemical reactions onto on-chip trapped structures and we demonstrate how the synthetic pathway of a crystalline molecular material and its positioning inside a microfluidic channel can be precisely modified with this technology. This approach provides new opportunities for the controlled assembly of structures on surface and for their subsequent treatment

Profundización en metodologías y espacios docentes innovadores

Fac. de FilologíaFALSEsubmitte

Crecimiento y propiedades de capas muy delgadasde óxidos, y su interacción con metales depositados en su superficie

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid. Facultad de Ciencias. Departamento de Física de Apliques. Fecha de lectura: 11-09-198

In-situ scrutiny of the relationship between polymorphic phases and properties of self-assembled monolayers of a biphenyl based thiol

Two polymorphic phases of ω-(4'-methylbiphenyl-4-yl) butane-1-thiol (BP4) molecules formed on Au(111) were investigated by multidimensional atomic force microscopy, combining conductivity measurements, electrostatic characterization, friction force mapping, and normal force spectroscopy. Based on the same molecular structure but differing in molecular order, packing density, and molecular tilt, the two phases serve as a test bench to establish the structure-property relationships in self-assembled monolayers (SAMs). From a detailed analysis of the charge transport and electrostatics, the contributions of geometrical and electronic effects to the tunneling are discussed

Real space demonstration of induced crystalline 3D nanostructuration of organic layers

La filiació de Marcos Paradinas Aranjuelo en el moment de la publicació és l'Institut Català de Nanociència i NanotecnologiaThe controlled 3D nanostructuration of molecular layers of the semiconducting molecules CH (pentacene) and N,N'-dioctyl-3,4,9,10-perylene tetracarboxylic diimide (PTCDI-C8) is addressed. A tip-assisted method using atomic force microscopy (AFM) is developed for removing part of the organic material and relocating it in up to six layer thick nanostructures. Moreover, unconventional molecular scale imaging combining diverse friction force microscopy modes reveals the stacking sequence of the piled layers. In particular, we unambiguously achieve epitaxial growth, an issue of fundamental importance in thin film strategies for the nanostructuration of more efficient organic nanodevices