Dpto. Química Física y Química Inorgánica - Artículos de revista https://uvadoc.uva.es/handle/10324/1404 2026-07-13T06:07:00Z 2026-07-13T06:07:00Z Moro Marín, Adrián García Moreno, Gregorio José Coco Cea, Silverio https://uvadoc.uva.es/handle/10324/85269 2026-07-10T19:00:57Z 2026-01-01T00:00:00Z

We present a computational protocol to study the structural and optoelectronic properties of metal halide perovskites using non-periodic calculations (i.e., a cluster-based approach). The proposed framework strategically combines xTB, DFT and ONIOM methods, leveraging their strengths for accurate results with reduced computational cost. Using the CH3NH3PbI3 perovskite (MAPI) as a reference system, several cluster models (ranging from 204 to 2175 atoms) were constructed to preserve the chemical environment of the bulk phase and maintain electroneutrality. Structures were optimized with the GFN2-xTB method, while optoelectronic properties were computed at the PBE0-D4/Def2-TZVP level. For the larger systems (>1000 atoms), a two-layer ONIOM scheme was applied, treating the region of interest at the PBE0-D4/Def2-TZVP level, with the rest of the system treated using GFN2-xTB with electrostatic embedding. Our results show that GFN2-xTB is suitable for studying the structural properties of perovskites. Regarding optoelectronic properties, the DFT-calculated bandgap is strongly overestimated for smaller clusters due to nanosizing effects. Meanwhile, for larger systems, results based on a two-layer ONIOM approach significantly enhance the accuracy of computed optoelectronic properties. Overall, this framework offers a reliable and efficient alternative to periodic calculations, broadening the range of computational tools available for studying halide perovskites.

2026-01-01T00:00:00Z Batra, Gayatri Schnell, Melanie Hansen, Poul Erik Pinacho Morante, Pablo https://uvadoc.uva.es/handle/10324/85167 2026-07-09T19:02:35Z 2026-01-01T00:00:00Z

The interplay between resonance-assisted hydrogen bonding and steric repulsions determines the structural stability of conjugated systems. To investigate the relation between electronic effects and π-delocalization in heteronuclear N-H⋯O interactions, the rotational spectra of three β-enaminone derivatives were investigated in the gas phase using a chirped-pulse Fourier transform microwave spectrometer. The three compounds were selected to probe the effects of donor acidity, steric repulsion, and extended π-conjugation. Contrary to previous models which predict a hydrogen bond strengthening in fully planar conjugated systems, the present results revealed that a twisted structure exhibits the strongest intramolecular hydrogen bond, while they are weaker for a planar analog. These experimental findings, corroborated by natural bond orbital analysis, demonstrate that for these compounds substituent-induced enhancement of donor acidity is more important for the strengthening of intramolecular interaction than the extent of the π-conjugation.

2026-01-01T00:00:00Z Castillo, Roger Verde, Andrés Blanco, Susana López, Juan C. Macario, Alberto Pinacho, Pablo https://uvadoc.uva.es/handle/10324/85166 2026-06-30T19:04:09Z 2026-01-01T00:00:00Z

Azobenzene is a widely used molecular photoswitch, yet its gas-phase structure has been the subject of a long-standing controversy. The global minimum, the trans isomer, is planar and centrosymmetric, possessing no dipole moment and making it impossible to study by microwave spectroscopy. To overcome this challenge, we employed a molecular tagging approach to indirectly probe its molecular structure by generating a complex between azobenzene and water. This complex was characterized using chirped-pulse Fourier transform microwave (CP-FTMW) spectroscopy in the 2–8 GHz region, granting for an unambiguous determination of its structure. The cluster is stabilized by an O–H···N hydrogen bonding to one of the azo nitrogen atoms, supplemented by secondary C–H···O interactions. A key structural feature is that the azobenzene monomer within the cluster is significantly distorted from planarity, in contrast to the most stable monomer in the gas phase.

2026-01-01T00:00:00Z Ferraro, Valentina Sole, Roberto Álvarez Miguel, Lucía https://uvadoc.uva.es/handle/10324/84248 2026-04-21T19:21:38Z 2023-01-01T00:00:00Z

Three neutral Cu(I) complexes bearing 2,6-dimethylphenyl isocyanide (CNXyl) and different triatomic pseudohalogens (SCN−, OCN− and N3−) as ligands were efficiently synthesized and characterized. The solid-state structures were unambiguously determined through single-crystal X-ray diffraction, revealing unexpected bridging coordination modes in the case of OCN− and N3−. All the complexes were tested for azide-alkyne cycloaddition (CuAAC), showing interesting catalytic activity towards the formation of 1,4-disubstituted-1,2,3-triazoles for the cyanato and the azido Cu(I) complexes. Both species afforded yields above 90% with 0.5 mol% of catalyst at 50°C for 24 h. Several alkynes and azides were tested using the more active azido Cu(I) complex, affording the corresponding triazoles in high yields. The azido Cu(I) complex also induced the intramolecular CuAAC in the presence of dimethyl acetylenedicarboxylate and benzyl bromide/phenylacetylene.

2023-01-01T00:00:00Z Esposito, Elisa Carta, Mariolino Fuoco, Alessio Monteleone, Marcello Comesaña Gandara, Bibiana Gkaniatsou, Effrosyni Sicard, Clémence Wang, Sujing Serre, Christian McKeown, Neil B. Jansen, Johannes C. https://uvadoc.uva.es/handle/10324/82695 2026-02-11T21:00:47Z 2024-01-01T00:00:00Z

The gas transport properties of mixed matrix membranes (MMMs), prepared by dispersing nanoparticles of MOFs MIL-101(Cr) or MIL-177(Ti) into highly permeable Polymers of Intrinsic Microporosity PIM-EA-TB or PIM-TMN-Trip, were investigated. The homogeneity of the dispersion was confirmed by means of Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray (EDX) mapping analysis. Single gas time-lag measurements provided the permeability and ideal selectivity of different gas pairs, both after treatment of the MMMs with methanol and after natural aging over an extended period (up to 2000 days). This data demonstrated that the gas size-sieving pores of MIL-101(Cr) and MIL-177(Ti) and their good dispersion into the PIM matrix results in MMMs with enhanced gas separation performance, as compared to films composed solely of the polymer. The comparison of actual permeability with the Maxwell model for PIM-EA-TB with both MOFs confirmed the good dispersion and the absence of anomalies, whereas the inconsistency of permeability with prediction data for PIM-TMN-Trip suggests that the MOFs improved the polymer properties, stiffening or occupying the polymer free volume. In particular, the incorporation of MIL-101(Cr) into PIM-EA-TB significantly enhances the H2 permeability from ∼6000 to 13,000 Barrer, with a concurrent increase of the H2/N2 selectivity from 14 to 21. MIL-177(Ti) also enhances the H2/N2 selectivity to 20 due to a slight reduction of the N2 permeability. The addition of MIL-101(Cr) and MIL-177(Ti) into the ultra-permeable PIM-TMN-Trip showed more modest increases in H2 permeability and H2/N2 selectivity from 4.6 to ∼ 10. Hence the data for some of the MMMs surpass the 2008, and even approach the 2015/2019 Robeson’s upper bounds, particularly for gas pairs including H2.

2024-01-01T00:00:00Z Arriaza Echanes, Carolina Krüger, Gabriel I. Comesaña Gandara, Bibiana Terraza, Claudio A. Sanhueza, Loreto Ortiz, Pablo A. https://uvadoc.uva.es/handle/10324/82694 2026-02-11T20:01:13Z 2025-01-01T00:00:00Z

Overheating in miniaturized electronic devices can reduce their useful life, where conventional heat sinks are insufficient. The utilization of ionenes as solid–solid phase change materials is proposed to enhance thermal dissipation without the risk of leakage. In this work, a series of imidazolium ionenes with structural modifications in their aromatic core and aliphatic chain length were synthesized. The synthesis was carried out using the respective monomers diimidazole and alkyl dibromide, followed by counterion bromide exchange using lithium bis(trifluoromethanesulfonyl)imide, with yields over 90% in all cases. Thermal characterizations showed that all ionenes are heat-resistant, with degradation temperatures between 421 °C and 432 °C; moreover, they all presented only a solid–solid transition (Tg) as a phase change, between 59 °C and 28 °C, which varied depending on the aromatic core used and the length of the aliphatic chain. The obtained ionenes were introduced into an experimental device with an operating temperature of 40 °C, to be evaluated as solid–solid phase change materials in heat sinks. These demonstrated an average decrease in operating temperature of 9 °C compared to the device without ionenes. On the other hand, the stability of the ionenes was analyzed over 10 thermal cycles at 40 °C at a heating rate of 5 °C/min. This analysis demonstrated that the ionenes did not present changes or degradation during the evaluated cycles. These findings demonstrate that imidazolium ionenes are promising solid–solid phase change materials for use as efficient and self-repairing heat sinks in compact electronic devices.

2025-01-01T00:00:00Z Rizzuto, Carmen Nardelli, Francesca Monteleone, Marcello Calucci, Lucia Bezzu, Caterina Grazia Carta, Mariolino Tocci, Elena Esposito, Elisa De Luca, Giorgio Comesaña Gandara, Bibiana McKeown, Neil Bruce Sayginer, Bekir Budd, Peter M. Jansen, Johannes Carolus Fuoco, Alesio https://uvadoc.uva.es/handle/10324/82690 2026-02-11T20:01:11Z 2025-01-01T00:00:00Z

Previously, it has been reported that amine-PIM-1, a polymer of intrinsic microporosity obtained by reduction of nitrile groups of PIM-1 to primary amine groups, shows enhanced CO2 selectivity during mixed gas permeation studies with respect to single gas measurements for gas pairs involving CO2. This distinct and potentially useful behaviour was ascribed to the affinity of CO2 for the polymer amine groups. Here, we demonstrate that enhanced selectivity originates from both CO2 physisorption and chemisorption. A combination of 13C and 15N solid-state NMR spectroscopic analyses of a CO2-loaded amine-PIM-1 membrane allowed the identification and quantitative determination of both chemisorbed and physisorbed species and the characterization of polymer-CO2 interactions. Experiments with 13C isotopically enriched CO2 unequivocally demonstrated the conversion of 20% of the NH2 groups into carbamic acids at 298 K and a CO2 pressure of 1 bar. Chemisorption was supported by the strong heat of CO2 adsorption for amine-PIM-1 that was estimated as 50 kJ mol−1. Molecular dynamics simulations with models based on the experimentally determined polymer structure gave a detailed description of intra- and interchain hydrogen bond interactions in amine-PIM-1 after chemisorption, as well as of the effect of chemisorption on polymer porosity and physisorption.

2025-01-01T00:00:00Z Alonso Alonso, Elena Rita Kolesniková, Lucie Belloche, Arnaud Mata, Santiago Garrod, Robin T. Jabri, Atef León Ona, Iker Guillemin, Jean-Claude Müller, Holger S.P. Menten, Karl Alonso Hernández, José Luis https://uvadoc.uva.es/handle/10324/81579 2026-04-14T12:41:40Z 2021-01-01T00:00:00Z

For all the amides detected in the interstellar medium (ISM), the corresponding nitriles or isonitriles have also been detected in the ISM, some of which have relatively high abundances. Among the abundant nitriles for which the corresponding amide has not yet been detected is cyanoacetylene (HCCCN), whose amide counterpart is propiolamide (HCCC(O)NH ). With the aim of supporting searches for this amide in the ISM, we provide a complete rotational study of propiolamide from 6 GHz to 440 GHz using rotational spectroscopic techniques in the frequency and time domain. We identified and measured more than 5500 distinct frequency lines of propiolamide and obtained accurate sets of spectroscopic parameters for the ground state and the three low-lying excited vibrational states. We used the ReMoCA spectral line survey performed with the Atacama Large Millimeter/submillimeter Array toward the star-forming region Sgr B2(N) to search for propiolamide. We report the nondetection of propiolamide toward the hot cores Sgr B2(N1S) and Sgr B2(N2). We find that propiolamide is at least 50 and 13 times less abundant than acetamide in Sgr B2(N1S) and Sgr B2(N2), respectively, indicating that the abundance difference between both amides is more pronounced by at least a factor of 8 and 2, respectively, than for their corresponding nitriles. Although propiolamide has yet to be included in astrochemical modeling networks, the observed upper limit to the ratio of propiolamide to acetamide seems consistent with the ratios of related species as determined from past simulations.

2021-01-01T00:00:00Z Uribe, Lina Mato Domínguez, Sergio Crisci, Luigi Municio, Sofia Alonso Alonso, Elena Rita Alonso Hernández, José Luis León Ona, Iker Barone, Vincenzo https://uvadoc.uva.es/handle/10324/81567 2026-04-09T07:51:32Z 2025-01-01T00:00:00Z

Tiopronin, an N-substituted glycine derivative bearing a thiol group, is structurally related to HS-peptides, species of increasing interest in prebiotic chemistry. These thiol-terminated peptides, plausibly formed through abiotic dry-down reactions of mercaptoacids and amino acids, represent viable alternatives to classical peptide formation pathways. In this work, we investigate the conformational landscape of tiopronin by combining high-resolution microwave spectroscopy with quantum-chemical calculations. The Pisa composite schemes (PCS) were employed to locate low-energy conformers and to compute their ground-state rotational constants, which are directly comparable with experimental values. The accuracy of the theoretical results enables an unambiguous spectral assignment and a reliable structural interpretation, demonstrating the usefulness of an integrated experimental/theoretical approach, provided that the underlying quantum-chemical description captures accurate equilibrium values and vibrational averaging effects. More broadly, this strategy is well suited for the reliable characterization of other flexible prebiotic and biochemical building blocks.

2025-01-01T00:00:00Z Uribe, Lina Mendolicchio, Marco Municio, Sofia Mato Domínguez, Sergio Alonso Alonso, Elena Rita Alonso Hernández, José Luis León Ona, Iker Barone, Vincenzo https://uvadoc.uva.es/handle/10324/81565 2026-04-09T08:08:41Z 2025-01-01T00:00:00Z

We present an efficient semiexperimental protocol for determining spectroscopically accurate molecular structures from limited isotopologue data with a focus on medium-sized organic molecules. The availability of all monosubstituted isotopologues of norbornadiene enabled the determination of a complete semiexperimental (reqSE) equilibrium structure, establishing a reference for validating reduced-dimensionality approaches that avoid deuterium substitution. The rotational spectrum of norcamphor is reported here for the first time, providing a critical benchmark for assessing the method’s accuracy. By combining composite quantum-chemical calculations with a cost-effective vibrational correction scheme, the protocol achieves near-spectroscopic accuracy while substantially reducing the computational effort. This approach enables the structural characterization of large systems where extensive isotopic substitution is impractical, thereby broadening the applicability of semiexperimental methods in modern molecular spectroscopy.

2025-01-01T00:00:00Z Juárez López, Gabriela Sanz Novo, Miguel Aguado Vesperinas, Raúl Alonso Hernández, José Luis León Ona, Iker Alonso Alonso, Elena Rita https://uvadoc.uva.es/handle/10324/81564 2026-03-20T09:22:18Z 2023-01-01T00:00:00Z

This work reports a complete conformational analysis of caffeic acid, an exceptionally versatile pharmacophore, using laser ablation chirped-pulse Fourier transform microwave spectroscopy. The whole conformational space consisting of eight distinct species has been fully deciphered based on the trend of the rotational constants supported by theoretical computations. We show how rotational spectroscopy can be confidently used to distinguish between conformers even when the structural differences are minimal, such as those involved in the conformational panorama of caffeic acid. Additionally, the structural information here provided, such as the planarity observed in all the conformers, could help to elucidate the mechanisms underlying the biological and pharmacological activity of hydroxycinnamic acids.

2023-01-01T00:00:00Z Mato Domínguez, Sergio Aguado Vesperinas, Raúl Mata, Santiago Alonso Hernández, José Luis León Ona, Iker https://uvadoc.uva.es/handle/10324/81563 2026-03-25T08:19:28Z 2022-01-01T00:00:00Z

Sulfanilamide, a widely used antibacterial drug, has been brought into the gas phase using laser ablation techniques, and its structure has been characterized in the isolated conditions of a supersonic expansion using Fourier transform microwave techniques. A single conformer stabilized by an N–H⋯O[double bond, length as m-dash]S intramolecular interaction in an equatorial disposition has been unequivocally characterized. To emulate the microsolvation process, we studied its hydrated cluster. The results show that a single water molecule alters the conformational preference and forces sulfanilamide to switch from its initial eclipsed configuration to a staggered disposition. The observed hydrated cluster adopts a structure in which water forms three hydrogen bonds with sulfanilamide stabilizing the molecule.

2022-01-01T00:00:00Z Juárez López, Gabriela Alonso Alonso, Elena Rita Sanz Novo, Miguel Alonso Hernández, José Luis León Ona, Iker https://uvadoc.uva.es/handle/10324/81538 2026-03-20T09:38:11Z 2022-01-01T00:00:00Z

The conformational landscape of β-D-allose, a rare sugar, was investigated using laser ablation in combination with high-resolution rotational spectroscopy. Altogether, three species are identified, exhibiting a counter-clockwise intramolecular hydrogen bond network. The effect of epimerization on the main aldohexose is also studied and, despite the main conformers being very similar, the position of the hydroxyl groups in allose allows the formation of considerably stronger intramolecular hydrogen bonds than in glucose, and this could explain the low abundance of β-D-allose in Nature.

2022-01-01T00:00:00Z Buades, Bárbara Picón, Antonio Berger, Emma León Ona, Iker Di Palo, Nicola Cousin, Seth L. Cocchi, Caterina Pellegrin, Eric Herrero Martín, Javier Mañas Valero, Samuel Coronado, Eugenio Danz, Thomas Draxl, Claudia Uemoto, Mitsuharu Yabana, Kazuhiro Schultze, Martin Wall, Simon Zürch, Michael Biegert, Jens https://uvadoc.uva.es/handle/10324/81534 2026-04-17T08:14:12Z 2021-01-01T00:00:00Z

Recent developments in attosecond technology led to table-top x-ray spectroscopy in the soft x-ray range, thus uniting the element- and state-specificity of core-level x-ray absorption spectroscopy with the time resolution to follow electronic dynamics in real-time. We describe recent work in attosecond technology and investigations into materials such as Si, SiO2, GaN, Al2O3, Ti, and TiO2, enabled by the convergence of these two capabilities. We showcase the state-of-the-art on isolated attosecond soft x-ray pulses for x-ray absorption near-edge spectroscopy to observe the 3d-state dynamics of the semi-metal TiS2 with attosecond resolution at the Ti L-edge (460 eV). We describe how the element- and state-specificity at the transition metal L-edge of the quantum material allows us to unambiguously identify how and where the optical field influences charge carriers. This precision elucidates that the Ti:3d conduction band states are efficiently photo-doped to a density of 1.9 × 1021 cm−3. The light-field induces coherent motion of intra-band carriers across 38% of the first Brillouin zone. Lastly, we describe the prospects with such unambiguous real-time observation of carrier dynamics in specific bonding or anti-bonding states and speculate that such capability will bring unprecedented opportunities toward an engineered approach for designer materials with pre-defined properties and efficiency. Examples are composites of semiconductors and insulators like Si, Ge, SiO2, GaN, BN, and quantum materials like graphene, transition metal dichalcogens, or high-Tc superconductors like NbN or LaBaCuO. Exiting are prospects to scrutinize canonical questions in multi-body physics, such as whether the electrons or lattice trigger phase transitions.

2021-01-01T00:00:00Z León Ona, Iker Montero, Raúl Longarte, Raúl Fernández, José Andrés https://uvadoc.uva.es/handle/10324/81530 2026-03-20T11:57:02Z 2021-01-01T00:00:00Z

Laser spectroscopy in jets is one of the main sources of structural data from molecular aggregates. Consequently, numerous and sophisticated experimental systems have been developed to extract precise information, which is usually interpreted in the light of quantum mechanical calculations. However, even with the most sophisticated experiments, it is sometimes difficult to interpret the experimental results. We present here the example of water dimer and how after almost 70 years, the assignment of its mass-resolved IR spectrum still generates controversy that extends toward the mechanism of ionization of water aggregates.

2021-01-01T00:00:00Z León Ona, Iker Alonso Alonso, Elena Rita Mata, Santiago Alonso Hernández, José Luis https://uvadoc.uva.es/handle/10324/81528 2026-03-20T09:25:45Z 2020-01-01T00:00:00Z

Herein, we present the first rotational study of the AlaAla dipeptide, brought into the gas phase by laser ablation. Two different structures have been unveiled in the isolated environment of a supersonic expansion by Fourier transform microwave spectroscopy. These structures have been identified through their rotational and 14N quadrupole coupling constants. The flexibility of the –NH2 and –COOH ends allows the formation of strong intramolecular interactions giving rise to five- and seven-membered ring configurations.

2020-01-01T00:00:00Z