Concepció Rovira

Self‐Assembled Tetragonal Prismatic Molecular Cage Highly Selective for Anionic π Guests

The metal-directed supramolecular synthetic approach has paved the way for the development of functional nanosized molecules. In this work, we report the preparation of the new nanocapsule 3·(CF(3)SO(3))(8) with a A(4 B(2) tetragonal prismatic geometry, where A corresponds to the dipalladium hexaazamacrocyclic complex Pd-1, and B corresponds to the tetraanionic form of palladium 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (2). The large void space of the inner cavity and the supramolecular affinity for guest molecules towards porphyrin-based hosts converts this nanoscale molecular 3D structure into a good candidate for host-guest chemistry. The interaction between this nanocage and different guest molecules has been studied by means of NMR, UV/Vis, ESI-MS, and DOSY experiments, from which highly selective molecular recognition has been found for anionic, planar-shaped π guests with association constants (K(a)) higher than 10(9) M(-1) , in front of non-interacting aromatic neutral or cationic substrates. DFT theoretical calculations provided insights to further understand this strong interaction. Nanocage 3·(CF(3)SO(3))(8) can not only strongly host one single molecule of M(dithiolene)(2) complexes (M=Au, Pt, Pd, and Ni), but also can finely tune their optical and redox properties. The very simple synthesis of both the supramolecular cage and the building blocks represents a step forward for the development of polyfunctional supramolecular nanovessels, which offer multiple applications as sensors or nanoreactors.

Magnetic conductors. Current approaches and achievements

Abstract The recent achievements of our group in the synthesis of molecular and polymeric materials combining conductivity and magnetism are presented. These results will be grouped in three main areas: (1) molecular magnetic conductors based upon TTF-type donors and discrete metal complexes and clusters (metal halides, metal cyanides, metal oxalates, polyoxometalate clusters,…), (2) conducting molecular ferromagnets based upon extended magnetic layers incorporating donors in between the inorganic layers and (3) conducting polymers incorporating magnetic complexes and clusters.

Direct micro-patterning of TTF-based organic conductors on flexible substrates

We describe a new facile chemistry-based technique for patterning films of organic conductors on a polymeric substrate that consists of directly writing on the organic conducting surface using a local heat source such as a laser beam.

A New Organic Conductor and a Novel Structural Phase Transition in the BEDT-TTF Trihalide Family**

decrease of transmission (absorption increase) appears. This decrease cannot be explained by the photodegradation effect and can be accounted for by the photoinduced reorientation of azo groups. The increase of the transmission from D (a minimum point in curve a) to E indicates that azo chromophores with their long axis oriented in the direction perpendicular to the pump polarization also become photodegraded. In curve b, a decrease of transmission after the initial fast jump is observed (see the inset of Fig. 4), which is attributed predominantly to the photoinduced orientation effects. After this decrease, photodegradation in the direction perpendicular to the pump polarization dominates and therefore the transmission increases. Compared to curve b, the fast decrease of the transmission from C to D in curve a is due to the fact that the concentration of the azo dye trans isomers with their orientation parallel to the p? pump polarization is higher due to the prior pk pump excitation. We have reported on the experimental investigation of PIB in thin films fabricated by electrostatic sequential adsorption of CRP films. The formation of this large birefringence is attributed to the polarization-selective photodegradation of the azo dyes within the matrix of the polyelectrolyte. The investigations on photoinduced absorption change, dichroism, Raman and infrared spectra support the conclusion. Photoinduced alignment of azobenzene chromophores results in only a small contribution to the birefringence. The molecular structural details of the polarization-dependent PDAC matrix controlled photodegradation of CR are not completely clear at the present time. Further investigation of the photochemical reaction is necessary in order to thoroughly understand the mechanism involved in the polarization-selective photodegradation process. Nevertheless, we have successfully recorded holographic gratings based on this unusual PIB effect. A diffraction efficiency of 9 % in the first order was obtained with just a 1.3 mm thick film. The recorded birefringent gratings were stable and did not exhibit any long-term decay. We also observed that heating does not remarkably change the diffraction of the recorded grating on the film up to ~290.0 C. Above this temperature, discoloration and loss of materials from the film surface is observed. With azo dye‐containing polymers where photoinduced pure orientation effects play a major role similar or even better refractive index modulations in special cases and stability while maintaining reversibility have been achieved. Given the stable (including thermal stability) PIB exhibited by the electrostatic self-assembly CRP films, the assembled dye‐molecular composite films are especially suited to irreversible applications, such as long-term optical data storage, light-weight diffractive optical elements, and low-cost phase retarders at red or near infrared wavelength.

New conducting molecular metal/polycarbonate bilayered composites: (ET)2IBr2/PC-, (BET)2IBr2/PC- and (BET)2I3/PC-films*

Abstract Preparation of thin layers of oriented microcrystals of molecular metals using chemical oxidation by either I 2 . IBr or ICl vaporous of the polycarbonate films containing 2 % of ET or BET is presented. Compositions and crystal structures of the conducting layers were analyzed by X-ray, ESR and Raman spectroscopies. The polycrystalline β-(BET) 2 I 3 layer reveals a metal-like R(T) dependence (d.c.) down to low temperature.

Synthesis and characterization of endohedral metallofulleride K(18-crown-6)[Ho@C82(C2v)]

Endohedral metallofulleride K(18-crown-6)[Ho@C82(C2v)] was synthesized for the first time using a redox reaction of endohedral metallofullerene Ho@C82(C2v) with the electron donor potassium perchlorotriphenylmethide K(18-crown-6)[C(C6Cl5)3]. The new salt was characterized by spectrophotometry and mass spectrometry.

Coexistence of Ferromagnetic Coupling and Intramolecular Electron Transfer in a Purely Organic Mixed-Valence Molecule with a Triplet Ground State

Abstract The magnetic study of a purely organic biradical anion presenting electron transfer and ferromagnetic coupling between two radical centers simultaneously is discussed. The mixed-valence molecule was first generated electrochemically and the electron transfer was detected by optical spectroscopy. ESR measurements not only made the determination of the ground state possible, but also gave further evidence of transient site-localisation of the extra electron.

COMMON SENSE: Cost-effective sensors, interoperable with international existing ocean observing systems, to meet EU policies requirements

The COMMON SENSE (CS) project aims to develop cost-effective, multi-functional innovative sensors to perform reliable in-situ measurements in the marine environment. The COMMON SENSE sensors will focus on key parameters including eutrophication, heavy metals, marine litter (microplastics) and underwater noise. The project will focus on increasing the availability of sensor data and observations through the development and implementation of the Common Sensor Web Platform (CSWP), a software platform that will integrate the COMMON SENSE sensor data and observations and deliver them to the Web, in standard formats and through standard interfaces.

Piezoresistive biocompatible membranes for flexible pressure sensors

The article reports a promising approach to engineering biocompatible and highly piezoresistive membranes for flexible weightless transparent pressure sensors. The developed membranes are based on bi layer (BL) films composing a polycarbonate (PC) matrix “self-metallized” with organic molecular metal β-(ET)2I3, were ET=bis(ethylenedithio) tetrathiafulvalene. The presented approach permits engineering biocompatible all-organic membranes with sensitivity to pressure being of 13 Ω/mmHg; this value is significantly over the sensitivity of the previous reported BL film-based membrane sensors.

High Piezoresistive Organic Film for Plastic Pressure Sensors

A flexible pressure sensor based on a bi layer (BL) organic film has been fabricated. The conducting microcrystalline layer of an organic molecular conductor is used as a high sensitive piezoresistive material to detect and transmit pressure data. The polymeric matrix serves as both diaphragm and support for the placement of the conducting layer over it. Remarkably, the different electronic circuits can be directly designed on the conducting microcrystalline layer using a very simple technique. The sensors based on BL films can be employed in innovative applications such as smart clothing and robotic interfaces.