SÁNCHEZ DE ARMAS , María Rocío

In this work, new coumarin based dyes for dye sensitized solar cells (DSSC) have been designed by introducing several substituent groups in different positions of the NKX-2311 structure. Two types of substitutions have been considered: the introduction of three electron-donating groups (–OH, –NH2, and –OCH3) and two different substituents with...

En este trabajo se han estudiado mediante métodos cuánticos que se describen en el capítulo 1 diferentes aspectos relacionados con el funcionamiento y la eficiencia de las celdas solares sensibilizadas con colorantes orgánicos. Por una parte se ha trabajado sobre los aspectos relacionados con el semiconductor que actúa como receptor de carga en...

A common feature of spin-crossover molecules deposited on a substrate is the presence of a residual proportion of high-spin (HS) molecules at low temperature, instead of the pure low-spin (LS) phase observed in the bulk. In this work, we analyse by means of periodic rPBE calculations, the deposition of a monolayer of an Fe(II) spin-crossover...

The BPY[Ni(dmit)2]2 molecular crystal synthesized by Naito and coworkers (J. Am. Chem. Soc., 2012, 134, 18656) was characterized as a photo-magnetic-conductor. This crystal is a nonmagnetic semiconductor in the dark and becomes a magnetic conductor after UV irradiation. This work analyzes the key ingredients of the observed photomagnetism and...

We explore the deposition of the spin-crossover [Fe(tzpy)2(NCS)2] complex on the Au(100) surface by means of density functional theory (DFT) based calculations. Two different routes have been employed: low-cost finite cluster-based calculations, where both the Fe complex and the surface are maintained fixed while the molecule approaches the...

The electronic structure and magnetic interactions of three representative members of the breathing crystal Cu(hfac)2LR family, mainly Cu(hfac)2LPr (1), Cu(hfac)2LBu·0.5C8H18 (2) and Cu(hfac)2LBu·0.5C8H10 (3), have been analyzed by means of periodic plane-wave based DFT+U calculations. These copper(II)-nitroxide based molecular magnets display...

The interaction at molecular level of the spin-crossover FeII((3,5-(CH3)2Pz)3BH)2 complex with the Au(111) surface is analyzed by means of rPBE periodic calculations. Our results show that the adsorption on the metallic surface enhances the transition energy, increasing the relative stability of the low spin (LS) state. The interaction indeed...

The molecular magnets Cu(hfac)2LR based on copper(II) and pyrazolyl-substituted nitronyl nitroxide radicals LR exhibit thermally and optically-induced magnetostructural transitions, similar to the spin-crossover and light-induced excited spin state trapping phenomena. The mechanism of the gradual change of the magnetic moment in Cu(hfac)2LR...

Guest molecules in the 3D Hofmann-type FeII spin-crossover (SCO) metal-organic frameworks modulate the magnetic properties of the host, modifying the spin state, transition temperature, width of the hysteresis loop and are responsible for the occurrence of a single-step or multistep spin transition. In this work we explore the guest-dependent...

We demonstrate visible pump soft X-ray probe near-edge X-ray absorption fine structure (NEXAFS) spectroscopy measurements at the carbon K edge on thin molecular films in the laboratory. This opens new opportunities through the use of laboratory equipment for chemical speciation. We investigate the metal-free porphyrin derivative...

Spin-crossover complexes embedded in nanodevices experience effects that are absent in the bulk that can modulate, quench and even suppress the spin-transition. In this work we explore, by means of state-of-the-art quantum chemistry calculations, different aspects of the integration of SCO molecules on active nanodevices, such as the geometry...

Using near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, the carbon backbone of sodium copper chlorophyllin (SCC), a widely used chlorophyll derivative, and its breakdown products are analyzed to elucidate their electronic structure and physicochemical properties. Using various sample preparation methods and complementary...

The effect of facet exposure in ceria nanostructures on the catalytic properties of Pd/CeO₂ during methanol decomposition was investigated. The results showed the structure sensitive nature of this reaction, with the catalytic activity depending on the facet exposed in the ceria nanostructures. Operando DRIFTS-MS and DFT calculations...

The purification of the α-olefins though challenging, is mandatory step for their use in the chemical industry. Since adsorptive separation using zeolites is one of the most promising alternatives for olefin/paraffin separation in terms of energy efficiency, we use a combination of experiments and molecular simulations to study the effect that...

Spin crossover (SCO) molecules are promising nanoscale magnetic switches due to their ability to modify their spin state under several stimuli. However, SCO systems face several bottlenecks when downscaling into nanoscale spintronic devices: their instability at the nanoscale, their insulating character and the lack of control when positioning...