Angeles peña-gallego

Angeles peña-gallego
University of Vigo | UVIGO · Department of Physical Chemistry

About

82
Publications
4,122
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761
Citations
Citations since 2016
29 Research Items
233 Citations
20162017201820192020202120220102030405060
20162017201820192020202120220102030405060
20162017201820192020202120220102030405060
20162017201820192020202120220102030405060
Introduction
Skills and Expertise

Publications

Publications (82)
Preprint
Full-text available
Electronic structure calculations have been carried out to examine the effect of protonation and water molecules on the heme group of peroxidases in different redox (ferric, ferrous, compounds I and II) and spin states. Shared geometries, spectroscopic properties at Soret region, and thermodynamics of peroxidases are discussed. B3LYP and M06-2X den...
Article
Push-pull organic compounds with p -conjugated backbones are attracting considerable interest in terms of their highly efficient (NLO) non-linear optical effects. In this respect, cyano groups constitute one of the strongest electron acceptors suitable for NLO materials. We herein report the first 1,1,4,4-tetracyanobutadiene (TCBD) spirobifluorene...
Article
Spirobifluorenes are an important class of spiro compounds frequently used in the field of organic electronics, yet harnessing spiroconjugation to reach high‐performance in such structural motifs remains to be explored. We herein prove that peripheral functionalization serves as a useful tool to control spiroconjugation in an ON/OFF manner on both...
Article
Full-text available
Herein, the power of multicenter electron delocalization analysis to elucidate the intricacies of concerted reaction mechanisms is brought to light by tracking the transition of [1,3] sigmatropic rearrangements from the high-barrier pericyclic mechanism in 1-butene to the barrierless pseudopericyclic mechanism in 1,2-diamino-1-nitrosooxyethane. Thi...
Article
Polycyclic iridaaromatic compounds are of great interest not only because of the contributions made in "aromatic chemistry", but also because of the possibility of improving the results of the applications of the corresponding organic analogues in different fields. Therefore, understanding the requirements necessary to build on demand this type of...
Article
Some of the most promising materials for application in molecular electronics and spintronics are based on diradical chains. Herein, the proposed relation between increasing conductance with length and diradical character is revisited using ab initio methods that account for the static electron correlation effects. Electron transmission was previou...
Article
Helical Molecular Orbitals—Hel‐MOs—have been tailored theoretically through the torsion angle of diphenylbutadiynes. Experimentally, suitable conformations have been locked by the synthesis of cyclic spirobifluorenes. In addition to present distinct Hel‐MOs, the developed systems are robust and feature remarkable, photophysical and chiroptical resp...
Article
The selective synthesis of a spirobifluorene-iridacyclopentadiene complex has been achieved through the corresponding methoxyalkenylcarbeneiridium complex. The chemoselectivity of the C–H bond activation over the precursor has been studied via DFT calculations on the relative energies of the E and Z isomers of several examples and compared with exp...
Article
The Clar Goblet, the first radical bowtie nanographene proposed by Erich Clar nearly 50 years ago, was recently synthesized. Bowtie nanographenes present quasi-degenerate magnetic ground states which make them so elusive as unique. We present a thorough analysis of the spin states energetics of Clar Goblet and bowtie nanographenes by a battery of e...
Article
Several theoretical studies have proposed strategies to generate helical molecular orbitals (Hel‐MOs) in [n]cumulenes. While chiral even‐[n] cumulenes feature Hel‐MOs, odd‐[n] cumulenes may also present them if the terminal groups lie on different planes. However, the proposed systems have been either experimentally unfeasible or resulted in opposi...
Article
The concept of "true unimolecular rectifier" was introduced by Aviram and Ratner in 1974. They proposed an electrical rectifier at molecular scale based on an asymmetric distribution of donor and acceptor moieties within a simple organic molecule. Subsequent works in the field of molecular electronics were devoted to improve this "ideal" rectifier...
Preprint
Several theoretical studies have proposed strategies to reach helical molecular orbitals (Hel-MOs) in [n]cumulenes. While chiral even-[n] cumulenes feature Hel-MOs, odd-[n] cumulenes may also present them if the terminal groups lie on different planes. However, the hitherto proposed systems have been either experimentally unfeasible or resulted in...
Article
Chiroptical spectroscopic methods serve as a practical tool for the structural characterization of chiral systems based on the interaction with polarized light. The higher sensitivity of these methods, compared with their achiral counterparts, not only enables the determination of absolute configuration and conformational preferences, but also supr...
Article
Even though collective electronic excitations in extended systems, also called plasmons, can be easily distinguished from single-electron excitations using classical and quantum electromagnetic theory, they are elusive at molecular scale. Thus, different schemes have been recently proposed to quantify the plasmonicity at molecular scale using class...
Article
Full-text available
It is well established that chiroptical responses, based on the unique reaction to circularly polarized light by chiral non-racemic systems, are sensitive to the stereochemistry of the featuring systems. This behavior has promoted the use of chiroptical spectroscopies as a mandatory tool in the structure determination of molecules for decades. Rece...
Article
An extraordinary new family of molecular junctions, inaccurately referred to as “anti-Ohmic” wires in the recent literature, has been proposed based on theoretical predictions. The unusual electron transport observed for these systems, characterized by a reversed exponential decay of their electrical conductance, might revolutionize the design of m...
Article
Spirobifluorene derivatives find use in many end‐user applications. Therefore, further expansion of their scope is the focus of many research studies. However, although the optical properties of spirobifluorenes can be greatly tuned through incorporation of metal complexes, to date, spirobifluorene metallaaromatics remain unknown. Taking advantage...
Article
Synthesis of molecularly imprinted polymers (MIPs) implies a previous pre-polymerization stage in which the template (the molecule for which the MIP offers the specific recognition cavities) interacts with the adequate functional monomer, just before the addition of the cross-linker and the initiator for performing the polymerization synthesis. The...
Article
Full-text available
The high sensitivity of chiroptical responses to conformational changes and supramolecular interactions has prompted an increasing interest in the development of chiroptical applications. However, prediction of and understanding the chiroptical responses of the necessary large systems may not be affordable for calculations at high levels of theory....
Preprint
Full-text available
The high sensitivity of chiroptical responses to conformational changes and supramolecular interactions has prompted an increasing interest in the development of chiroptical applications. However, prediction and understanding the chiroptical responses of the necessary large systems may not be affordable for calculations at high levels of theory. In...
Article
Synthesis of stable irida-binaphthyl and -phenanthryl complexes, the first examples of metallaaromatic biaryl atropisomers, has been achieved. The combination of experimental and theoretical studies revealed that the nature of these...
Preprint
Full-text available
The high sensitivity of chiroptical responses to conformational changes and supramolecular interactions has prompted an increasing interest in the development of chiroptical applications. However, prediction and understanding the chiroptical responses of the necessary large systems may not be affordable for calculations at high levels of theory. In...
Article
Second-order rate constants were determined for the chlorination reaction of 2,2,2-trifluoethylamine and benzylamine with N-chlorosuccinimide at 25 degrees C and an ionic strength of 0.5M. These reactions were found to be of first order in both reagents. According to the experimental results, a mechanism reaction was proposed in which a chlorine at...
Article
Full-text available
The mechanism of the decomposition of ethyl and ethyl 3-phenyl glycidate in gas phase was studied by density functional theory (DFT) and MP2 methods. A proposed mechanism for the reaction indicates that the ethyl side of the ester is eliminated as ethylene through a concerted six-membered cyclic transition state, and the unstable intermediate glyci...
Article
Nucleophilic aromatic substitution for nitro-activated substrates in the presence of glymes and crown ethers is reported. The kinetic study reveals the many-sided nature of the polyether-catalyzed SNAr mechanism as well as the main features affecting the course of the reaction. Thus, the process can be efficiently controlled by the catalyst through...
Article
The effect of microhydration on the interaction of guanidinium cation with benzene has been studied by employing ab initio calculations. Four different structural arrangements were considered for the guanidinium···benzene interaction to which up to six water molecules were added. T-shaped structures are usually the most stable, but as water molecul...
Article
The characteristics of the interaction between water and hydrogen sulfide with indole and a series of analogs obtained by substituting the NH group of indole by different heteroatoms have been studied by means of ab initio calculations. In all cases, minima were found corresponding to structures where water and hydrogen sulfide interact by means of...
Article
Full-text available
A comprehensive MP2/6-311 + G(d,p) and B3LYP/6-311 + G(d,p) study of the aromatic character of phospholes, Pn (CH)4-n PH with n = 0-4 was conducted. For this purpose, the structures for these compounds were optimized at both theoretical levels and different magnetic properties (magnetic susceptibility anisotropy, χanis, and the nucleus-independent...
Article
This work is focused in three topical subjects: intermolecular interactions, metal ions, and aromaticity. A comprehensive MP2/6-31 + G and B3LYP/6-31 + G study of the influence of cation-π interactions on the aromatic character of phosphole was conducted. For this purpose, the structures of complexes were optimized at both theoretical level and dif...
Article
A computational study of dimers formed by aniline and one or two CH3X molecules, X being CN, Cl or F, was carried out to elucidate the main characteristics of the interacting systems. Two different structures were found for each of the dimers, depending on the relative location of the CH3X molecule with respect to the NH2 hydrogen atoms. The most s...
Article
Full-text available
The mechanism for the decarbonylation of (E)-2-butenal and (E)-2-methyl-3-pheny-2-propenal was studied with different levels of ab initio and DFT methods. Reactants, products and transition structures were optimized for two kinds of reaction channel: a one-step reaction which involves a three-membered cyclic transition state, and a two-step reactio...
Article
Irigoras et al. found two isomers of the ferrocene–lithium cation complex by DFT calculations [Irigoras, A.; Mercero, J. M.; Silanes, I.; Ugalde, J. J. Am. Chem. Soc.2001, 123, 5040–5043]. The most stable isomer (I) of this complex has Li+ on top of one of the cyclopentadienyls, while in the least stable isomer (II) Li+ binds to the central iron me...
Article
A computational study was carried out for studying the characteristics of the interaction between azulene and water or hydrogen sulfide. In azulene...water complex the water molecule is located with both hydrogen atoms pointing toward the aromatic cloud but displaced to the five-membered ring. Hydrogen sulfide adopts a similar arrangement but locat...
Article
The characteristics of the interaction between the pi cloud of naphthalene and up to two H2O or H2S molecules were studied. Calculations show that clusters formed by naphthalene and one H2O or H2S molecule have similar geometric features, and also present similar interaction energies. Our best estimates for the interaction energy amount to -2.95 an...
Article
The characteristics of the interaction between phenol and acetonitrile, methyl fluoride and methyl chloride were studied. The most stable structures for clusters containing one or two CH3X molecules and one phenol moiety were located by means of ab initio and density functional theory calculations. Phenol-acetonitrile dimer presents two almost equa...
Article
NICS methodology has been applied to study the change in aromaticity in several aromatic rings on complexation with several ions. From the calculated values of NICS(1) and NICSZZ(1) the only relevant conclusion is that a very small change in aromaticity takes place. Moreover, a large discrepancy between the results from the two aromatic descriptors...
Conference Paper
Full-text available
NICS methodology has been applied to study the change in aromaticity in several aromatic rings (benzene, pyrrol, triazine, hexafluorobenzene) on complexation with several ions (Li + , Na + , K + . F -, Cl -). For this purpose all the isolated and complexed rings have been optimized at the MP2/6-31++G(d,p) level of theory. Using GIAO method to calcu...
Article
A comprehensive B3LYP/6-31+G∗ study of the influence of BF3 on the [4+2] cycloaddition of vinylketene with formaldimine was conducted. For this purpose, the complete pathway was determined and changes in different magnetic properties (magnetic susceptibility, χ, magnetic susceptibility anisotropy, χanis, and the nucleus-independent chemical shifts,...
Conference Paper
Full-text available
A computational study of clusters containing azulene and up to two molecules of water or hydrogen sulfide was carried out to elucidate the main characteristics of these X-H···π interacting systems. For clusters with one H 2 X molecule only one structure was found interacting with the aromatic cloud of azulene, with an interaction energy of -3.1 kca...
Article
A comprehensive B3LYP/6-31+G∗ study of the nature of the [4+2] cycloadditions of conjugated ketenes, vinylketene, imidoylketene and formylketene, with formaldimine was conducted. For each reaction, the complete pathway was determined and changes in different magnetic properties (magnetic susceptibility, χ, magnetic susceptibility anisotropy, χanis,...
Article
Electrocyclization reactions of o-divinylbenzene and several derivatives were studied by performing density functional theory (DFT) calculations together with the 6-31+G∗ basis set. Reactants, products and transition states for each reaction were localized and the path connecting reactants and products was also obtained. Along the reaction path, ma...
Article
A comprehensive B3LYP/6-31+G* study of the nature of 6pi electrocyclizations of four different dienylketenes (2-furanyl, 2-pyrrolyl, cyclopenta-1,3-dienyl, and 2-thiophenyl-substituted ketenes) to corresponding cyclohexadienones was carried out. An analogous system ((3Z)-4-(3H-pyrrol-2-yl)buta-1,3-dien-1-one) was also analyzed. For this purpose, th...
Article
A theoretical study of the ‘walk’ rearrangement in bicyclo[2.1.0]pentene and perfluorotetramethyl (Dewar thiophene) exo-S-oxide has been carried out. Despite the differences between them, the results for both reactions show an enhancement of aromaticity in the transition state, which is consistent with a pericyclic behavior. NBO calculations show t...
Article
A comprehensive B3LYP/6-31+G* study on the electrocyclization of 1,2,4,6-heptatetraene analogues was conducted. Starting from the cyclization of (2Z)-2,4,5-hexatrienal, a pericyclic disrotatory process favored by the assistance of a electron lone pair, we incorporated small modifications in its molecular structure to obtain a truly pseudopericyclic...
Article
A comprehensive B3LYP/6-31+G(2d,p) study of the nature of the concerted cyclisation of 3-azidopropenal to isoxazole was conducted. For this purpose, the complete pathway was determined and changes in different magnetic properties [magnetic susceptibility (χ), magnetic susceptibility anisotropy (χanis) and the nucleus-independent chemical shifts (NI...
Article
Cycloaddition reactions of ethylene and formaldehyde to buta-1,3-dien-1-one and derivatives were studied by performing a density functional theory study with the 6-31+G* basis set. Reactants, products, and transition states for each reaction were localized, and the path connecting reactants and products was also obtained. Magnetic properties were e...
Article
[reactions: see text] Electrocyclization reactions of (3Z)-1,3,5-hexatrienone and nitrogen derivatives were studied by performing density functional theory (DFT) calculations together with the 6-31+G* basis set. Reactants, products, and transition states for each reaction were localized and the IRC connecting reactants and products was also obtaine...
Article
The nature of the Boulton-Katritzky rearrangement of (5R)-4-nitrosobenz[c]isoxazole and its anion was studied employing three methodologies: calculation of magnetic properties (magnetic susceptibility, magnetic susceptibility anisotropy, and the nucleus-independent chemical shifts), the natural bonding orbital analysis, and the ACID (anisotropy of...
Article
A comprehensive B3LYP/6-31G** study of various thermal cheletropic decarbonylations was conducted. The complete pathway for each reaction was determined, and changes in magnetic susceptibility and its anisotropy were monitored with a view to estimating the aromatization associated to each process. This information, together with the energy and stru...
Article
The photodissociation of ethylene at 193 nm was studied by a B3LYP/6-31G(d) direct trajectory method, in which the trajectories were initialized from the two exit barriers associated to molecular hydrogen formation. The calculated translational energies and the H 2 rotational and vibrational states distributions are in good agreement with the exper...
Article
Ab initio MP2/6-31G(d,p) and density functional theory B3LYP/6-31G(d,p) calculations were performed to investigate the molecular structure of the active part of flavins in the oxidized and reduced forms, using lumiflavin as a model compound. The possible aromatic character of these systems was explored by using the following aromaticity indexes: nu...