A5024624312- Advanced Chemical Physics Studies
- Molecular Spectroscopy and Structure
- Spectroscopy and Quantum Chemical Studies
- Spectroscopy and Laser Applications
- Molecular spectroscopy and chirality
- Atmospheric Ozone and Climate
- Laser-Matter Interactions and Applications
- Astrophysics and Star Formation Studies
- Photochemistry and Electron Transfer Studies
- Analytical Chemistry and Chromatography
- Crystallography and molecular interactions
- Various Chemistry Research Topics
- Carbohydrate Chemistry and Synthesis
- X-ray Spectroscopy and Fluorescence Analysis
- Glycosylation and Glycoproteins Research
- Advanced Chemical Sensor Technologies
- Nicotinic Acetylcholine Receptors Study
- Atomic and Molecular Physics
- Mass Spectrometry Techniques and Applications
- Electron and X-Ray Spectroscopy Techniques
- Machine Learning in Materials Science
- Quantum, superfluid, helium dynamics
- Diamond and Carbon-based Materials Research
- Fluorine in Organic Chemistry
- Supramolecular Chemistry and Complexes
Universidad de Valladolid
2017-2025
Institute of Photonic Sciences
2016-2023
Consejo Superior de Investigaciones Científicas
2018-2021
University of the Basque Country
2009-2020
Comisión Sectorial de Investigación Científica
2017-2020
Universidad de Huelva
2020
University of Information Science
2019
Brown University
2013-2018
New College of Florida
2018
Ministerio de Ciencia y Tecnología
2017
A new velocity-map imaging apparatus equipped with a laser-vaporization supersonic cluster source and time-of-flight mass spectrometer is described for high-resolution photoelectron spectroscopy studies of size-selected anions. Vibrationally cold anion clusters are produced using source, by spectrometer, then focused co-linearly into the interaction zone (VMI) system. The multilens VMI system optimized via systematic simulations can reach resolution 1.2 cm−1 (FWHM) near threshold electrons...
Herein, we present the first experimental observation of isolated progesterone, an endogenous steroid, placed in gas phase by laser ablation and characterized a supersonic expansion Fourier transform microwave techniques. Guided quantum-chemical calculations, assigned rotational spectrum most stable structure. The internal rotation acetyl methyl group led to A-E doublets spectrum, which were analyzed, resulting V3 barrier 2.4425 ± 0.0025 kJ mol-1. By fitting over 250 transitions, determined...
Recent developments in attosecond technology led to tabletop X-ray spectroscopy the soft range, thus uniting element- and state-specificity of core-level x-ray absorption with time resolution follow electronic dynamics real time. We describe recent work investigations into materials such as Si, SiO2, GaN, Al2O3, Ti, TiO2, enabled by convergence these two capabilities. showcase state-of-the-art on isolated pulses for near edge (XANES) observe 3d-state semi-metal TiS2 at Ti L-edge (460 eV)....
Phase transitions of solids and structural transformations molecules are canonical examples important photo-induced processes, whose underlying mechanisms largely elude our comprehension due to inability correlate electronic excitation with atomic position in real time. Here, we present a decisive step towards such new methodology based on water-window-covering (284 eV 543 eV) attosecond soft X-ray pulses that can simultaneously access lattice parameters via dispersive absorption...
A combined experimental and theoretical study has been carried out on 4-fluoro-threonine, the only naturally occurring fluorinated amino acid. Fluorination of methyl group significantly increases conformational complexity with respect to parent acid threonine. The landscape characterized in great detail, special attention given inter-conversion pathways between different conformers. This led identification 13 stable low-energy minima. equilibrium population so many conformers produces a very...
Unraveling the exact nature of nonequilibrium and correlated interactions is paramount for continued progress in many areas condensed matter science. Such insight a prerequisite to develop an engineered approach smart materials with targeted properties designed address standing needs such as efficient light harvesting, energy storage, or information processing. For this goal, it critical unravel dynamics conversion processes between carriers earliest time scales excitation dynamics. We...
We report high resolution photoelectron spectra of Au2− using a newly built imaging apparatus. Vibrationally resolved images are obtained for the ground state detachment transition at various photon energies (442.80–670.18 nm) 3 cm−1 low energy electrons. Franck-Condon simulations yield vibrational temperature and data accurate spectroscopic constants states Au2 Au2−. The electron affinity is measured to be 1.9393 ± 0.0006 eV. A more precise value dissociation also as 1.937 0.005
Abstract Laboratory experiments on interstellar ice analogs have demonstrated that mixtures containing acetaldehyde (CH 3 CHO) and hydrogen cyanide (HCN) in the presence of ammonia (NH ), water (H 2 O), or an NH /H O mixture allow formation chiral molecule lactonitrile (2-hydroxypropionitrile; CH CH(OH)CN). These findings place among possible molecules, especially when its methyl-shortened derivative glycolonitrile precursors are known species. To support search for space, we present...
Abstract Herein we report on the most stable structures adopted by piracetam, a nootropic drug, in isolated conditions. A chirped pulse Fourier transform microwave spectrometer (CP‐FTMW) coupled with laser ablation source has been employed to explore broadband rotational spectrum of piracetam 6.0–14.0 GHz range. Two conformers have observed. The conformer adopts an exo configuration ring and is mainly stabilized through N−H⋅⋅⋅⋅⋅⋅O=C hydrogen bond between amide group rings′ carbonyl oxygen....
Propofol (2,6-diisopropylphenol) is a broadly used general anesthetic. By combining spectroscopic techniques such as 1- and 2-color REMPI, UV/UV hole burning, infrared ion-dip spectroscopy (IRIDS) obtained under cooled isolated conditions with high-level ab initio calculations, detailed information on the molecular structure of propofol its interactions water can be obtained. Four isomers are found for bare propofol, while only three detected monohydrated species two propofol·(H2O)2. The...
High resolution photoelectron spectroscopy of Au4 (-) is reported using a new imaging apparatus. A broad vibrational progression resolved for the detachment transition from ground electronic state Y-shaped to that neutral (C2v, (1)A1) in ν2 mode with harmonic frequency 171(7) cm(-1) and an anharmonicity ∼0.5 cm(-1). In addition, two low modes weak Franck-Condon factors are observed: v3 97(7) v6 17(7) An accurate electron affinity 2.7098(6) eV obtained cluster. The current study shows very...
Histone-DNA interactions were probed computationally at a molecular level, by characterizing the bimolecular clusters constituted selected amino acid derivatives with polar (asparagine and glutamine), nonpolar (alanine, valine, isoleucine), charged (arginine) side chains methylated pyrimidinic (1-methylcytosine 1-methylthymine) puric (9-methyladenine 9-methylguanine) DNA bases. The computational approach combined different methodologies: mechanics (MMFFs forced field) conformational search...
Abstract Numerous studies have suggested that the n→π* interactions between carbonyls could contribute significantly to stability of proteins. Nevertheless, their evaluation is challenging because solvent environment or crystal packing forces in solids. Here we study rotational spectrum HGlyProOH dipeptide, a very common sequence found collagen, most abundant protein vertebrates, isolated conditions. Three different structures are unequivocally characterized gas phase. Interestingly,...
Abstract Neutral glutamine has been evaporated by laser ablation of its solid sample to seed a rare gas carrier prior supersonic expansion and proved Fourier transform microwave techniques. We report on three distinct neutral conformers that show singular non‐interacting flexible amide sidechain in contrast with the other proteinogenic aliphatic amino acids. It could explain essential biological role as nitrogen source, unique ability form variety hydrogen bonds peptide backbones. Common...
A subtle interplay: In the formation of a 1.6 nm micelle containing up to six molecules propofol, hydrogen-bond network is shown influence structure micelle, whereas nonpolar groups arrange in such way that remaining noncovalent interactions are maximized. Such globular structures present characteristic signature IR spectrum will allow their identification more complex media.
Cycloserine has in common with isoxazolidines the saturated five-membered ring, which is an important scaffold for drug design, exhibiting diverse biological activities. The most remarkable feature of these compounds presence N–O bond framed a cyclic moiety. lack accurate characterization this structural isolated system calls state-of-the-art theoretical–experimental study. A quantum–chemical investigation cycloserine unveiled 11 local energy minima, only two them being separated by...
Abstract The unbiased, naked structures of tartaric acid, one the most important organic compounds existing in nature and a candidate to be present interstellar medium, has been revealed this work for first time. Solid samples its naturally occurring (R,R) enantiomer have vaporized by laser ablation, expanded supersonic jet, characterized Fourier transform microwave spectroscopy. In isolation conditions we discovered up five different stabilized intramolecular hydrogen‐bond networks...
We have successfully characterized the structure of testosterone, one essential steroids, through high-resolution rotational spectroscopy. A single conformer has been detected, and a total 404 transitions fitted, allowing precise determination constants. It allowed us to unravel that isolated testosterone adopts an extended disposition. The results obtained in this work highlight how using laser ablation techniques combination with Fourier transform microwave allow study large biomolecules...
An integrated experimental–computational strategy for the accurate characterization of conformational landscape flexible biomolecule building blocks is proposed. This based on combination rotational spectroscopy with quantum-chemical computations guided by artificial intelligence tools. The first step conformer search and relative stability evaluation performed means an evolutionary algorithm. In this step, last generation semiempirical methods are exploited together hybrid double-hybrid...
We report photoelectron spectroscopy (PES) and high-resolution PE imaging of AuC2− at a wide range photon energies. The ground state is found to be linear (C∞v, 1Σ+) with …8π44δ417σ29π418σ2 valence configuration. Detachments from all the five orbitals are observed 193 nm. High-resolution images obtained in energy 830 330 nm, revealing complicated vibronic structures electron detachment 18σ, 9π, 17σ orbitals. Detachment 18σ orbital results 2Σ+ neutral AuC2, which, however, bent due strong...
The steric effects imposed by the isopropyl group of valine in conformational stabilization capped dipeptide N-acetyl-l-valinamide (Ac-Val-NH2) have been studied laser ablation molecular beam Fourier transform microwave (LA-MB-FTMW) spectroscopy. rotational and quadrupole coupling constants two 14N nuclei determined this work show that exists as a mixture C7 C5 conformers supersonic expansion. are stabilized C[double bond, length m-dash]OH-N intramolecular hydrogen bond closing seven- or...
Sugars are fundamental building blocks for living organisms and their interaction with proteins plays a central role in biological processes, such as energy storage production, post-transductional modifications or immune response. Understanding those processes require deep knowledge of the forces that drive interactions at molecular level. Here we explore between α/β-methyl-d-glucopyranose β-phenyl-d-glucopyranose phenol, chromophore tyrosine, using combination mass-resolved laser electronic...
Abstract Weaker intermolecular forces expand the isomerization alternatives for molecular aggregation, as observed prototype models of aniline trimer (An 3 ) and monohydrated dimer 2 ‐W) when compared to phenol trimer. In this experiment clusters were generated in a jet‐cooled expansion probed using broadband (chirped‐pulsed) microwave spectroscopy. Three isomers two hydrated detected characterized rotational spectrum. homotrimer weak N−H⋅⋅⋅N hydrogen bonds are assisted by subtle...
Propofol is a general anaesthetic that exerts its action by interaction with the GABA(A) receptor. Crystallographic studies suggest there direct between propofol and phenolic residue of tyrosine in channel. In this study we create propofol···phenol clusters their co-expansion jets. The complex probed using set mass-resolved spectroscopic strategies: 2-color REMPI, UV/UV hole-burning, IR/UV double resonance novel technique IR/IR/UV triple resonance. existence at least six different isomers...
We report a joint photoelectron spectroscopy and theoretical study on AuC4−, AuC6−, AuCnH− (n = 2, 4, 6) using high-resolution imaging ab initio calculations. The ground state of AuC2H−, AuC4H−, AuC6H− is found to be linear, while that AuC4− AuC6− bent. All the species are linear in their neutral states. electron affinities (EAs) measured 3.366(1) 3.593(1) eV for AuC4 AuC6, respectively. Both bending stretching frequencies resolved spectra AuC6−. High-resolution data reveal major vibrational...