Aromaticity rules. A comment article in Nature Chemistry

Since the formulation of the Hückel’s rule, a variety of rules have been proposed to determine if a molecule is aromatic. These allow chemists to better understand molecules and their behavior, as well as identify the formation or elimination of (anti)aromatic species in a reaction, which helps understand and predict possible outcomes. In this comment article, Prof. Miquel Solà first briefly discusses the most widespread rules associated with different types of aromaticity, then draws attention to their limitations, and finally propose future directions for the development of this fascinating topic.

The paper can be read in Nature Chemistry journal through the following link:

Directed evolution for abiological radical-relay C(sp3)−H azidation. First Science publication of our group!

In this work, we show that it is possible to perform directed evolution guided by computational results (performed in our group) to reprogram nonheme iron enzymes to catalyze an abiological C(sp3)‒H azidation reaction through iron-catalyzed radical relay. This biocatalytic transformation uses amidyl radicals as hydrogen atom abstractors and Fe(III)‒Nintermediates as radical trapping agents. We established a high-throughput screening platform based on click chemistry for rapid evolution of the catalytic performance of identified enzymes. The final optimized variants deliver a range of azidation products with up to 10,600 total turnovers and 93% enantiomeric excess. Given the prevalence of radical relay reactions in organic synthesis and the diversity of nonheme iron enzymes, we envision that this discovery will stimulate future development of metalloenzyme catalysts for synthetically useful transformations unexplored by natural evolution.

This work was carried out by J. Rui, Q. Zhao, A. J. Huls, Z. Chen, V. Reshetnikov and Prof. X. Huang from the Department of Chemistry of the Johns Hopkins University, J. C. Paris and Prof. Y. Guo from the Department of Chemistry of Carnegie University and J. Soler and Dr. M. Garcia-Borràs from the DiMoCat group of the Institute of Computational Chemistry and Catalysis of the University of Girona.

We are very proud of the work by Marc Garcia-Borràs and Jordi Soler! Congratulations!!!


Jinyan Rui, Qun Zhao, Anthony J. Huls, Jordi Soler, Jared C. Paris, Zhenhong Chen, Viktor Reshetnikov, Yunfang Yang, Yisong Guo*, Marc Garcia-Borràs* and Xiongyi Huang*. Directed evolution of nonheme iron enzymes to access abiological radical-relay C(sp3)-H azidation. Science, 2022, 376, 6595. DOI: 10.1126/science.abj2830.


Photoinduced electron transfer in suit[3]ane species in the Front Cover of J. Mat. Chem. C!

Sustainable catalysis by Mn: Amide Synthesis from Alcohols and generation of H2 as energy source

Density functional theory calculations unveil the mechanism of the original example of a base-metal-catalyzed synthesis of amides from alcohols and amines, generating H2 as a subproduct. Instead of a convoluted mechanism with the implication of dissociation of some ligand of the manganese catalyst, our DFT calculations describe a facile protocol, where the catalyst only produces aldehydes from alcohols. Once formaldehyde is formed from methanol, it reacts with the amine to form a second alcohol that undergoes the same procedure as methanol and creates the desired amide through a double-carrousel mechanism. This reaction is eminently sustainable in different ways: it uses alcohols and generates molecular hydrogen, without releasing CO2, but the interesting formation of amides. In addition, to speed up the process the reaction has a manganese catalyst, with manganese being one of the most abundant metals in the Earth’s layer.

A. Luque-Urrutia, T. Pèlachs, M. Solà, A. Poater; “Double-Carrousel Mechanism for Mn-Catalyzed Dehydrogenative Amide Synthesis from Alcohols”; ACS Catal. 2021, DOI: 10.1021/acscatal.1c00693

Dr. Jesús Antonio Luque Urrutia, new doctor of the DiMoCat group

On 26th March 2021, Jesús Antonio Luque Urrutia, “Xus”, defended with success his PhD thesis entitled “Computational Studies Oriented Towards the Development of a Greener Chemistry”. The PhD thesis was supervised by Dr. Albert Poater and Prof. Miquel Solà (see photo). The evaluation committee was composed by Dr. Josep M. Luis (University of Girona) as president, Dr. Laura Falivene (Università degli Studi di Salerno), and Dr. Diego Andrada (Saarland University) as secretary. The defense was done by videoconference due to the COVID-19 pandemic and the PhD thesis was qualified with the highest mark of Excellent.

During his PhD, Dr. Luque had an IFUdG grant awarded by the University of Girona and he has published seven papers, including a JACS and an ACS Catalysis. In the coming weeks, he will start a postdoc in the group of Prof. Albert Rimola at the Autonomous University of Barcelona. We wish him good luck and great successes!

The aromaticity of boron clusters in the Front Cover of JACS!

The Journal of the American Chemical Society (JACS) features in its FRONT COVER the recently published article “Too Persistent to Give Up: Aromaticity in Boron Clusters Survives Radical Structural Changes”. The work has been carried out by Prof. Francesc Teixidor, Prof. Clara Viñas, and Dr. Ines Bennour of the Institute of Materials Science of Barcelona (ICMAB-CSIC), Prof. Jordi Poater at the University of Barcelona (previous DiMoCat member) and Sílvia Escayola and Prof. Miquel Solà members of the DiMoCat group of the Institute of Computational Chemistry and Catalysis of the University of Girona. The cover is the result of the artistic inspiration of Sílvia Escayola.

We paper is also highlighted by the editor in the Spotlights on Recent JACS Publications.

You can go to the JACS website to read the abstract and the full article “Too Persistent to Give Up: Aromaticity in Boron Clusters Survives Radical Structural Changes”.

Jordi Poater, Clara Viñas, Ines Bennour, Sílvia Escayola, Miquel Solà*, Francesc Teixidor*
J. Am. Chem. Soc. 2020, 1429396–9407.


Two new PhD students in the DiMoCat group

We have recently incorporated two new PhD students in our group with two cotutelle agreements.

First, Daniel Eduardo Trujillo that will perform a theoretical study of the electronic structure and reaction mechanisms of reactions of multiple-bound boron compounds that can activate C-C and C-H bonds. Daniel will be supervised by J. Oscar C. Jimenez-Halla and Gerardo Gonzalez in the University of Guanajauto (Mexico) and Miquel Solà in the University of Girona.

A photo of Daniel E. Trujillo

Second, Dandan Chen that will be working in the study of aromatic species with special emphasis in metalloaromatic species in excited states. Dandan will be supervised by Jun Zhu in Xiamen University (China) and Miquel Solà in the University of Girona.

A photo of Dandan Chen

We wish Daniel and Dandan a great success with their PhD research!

Two recent DiMoCat works highlighted by ChemistryWorld

ChemistryWorld has recently highlighted two works of our group:

The jellium model assumes a uniform distribution of positive charge corresponding to the cluster atomic nuclei and their innermost electrons in which the interacting valence electrons move. The energy levels of valence electrons for such a model are 1S21P61D102S21F142P61G182D103S2…, where S, P, D, F, and G letters denote the angular momentum and numbers 1, 2, 3 indicate the radial nodes. The abundance found in experimental mass spectra of alkali, alkaline earth metals, and gold clusters of 2, 8, 18, 20, 34, 40… atoms are justified taken into account that these numbers correspond to closed-shell electronic structures in the jellium model. We have proven that if the last energy level of valence electrons for the jellium model is half-filled with same-spin electrons, the system has also an aromatic character that provides extra stability. This situation is reached for the magic numbers of valence electrons of 1 (S =1/2), 5 (S = 3/2), 13 (S = 5/2), 19 (S = 1/2), 27 (S = 7/2), 37 (S = 3/2), 49 (S = 9/2)… This new set of magic numbers may become a powerful tool for researchers who work in the quest for stable single high-spin molecules for their use as single-molecule based magnets. The paper has been published in Chem. Commun. and can be found in the following link Chem. Commun., 55 (2019) 5559-5562.

In this recent Chem. Commun. paper, we have proved that C18 (a cycle of 18 carbon atoms connected with alternating single and triple bonds) it is an electron acceptor of similar characteristics as C60. C18  when coupled with a range of donor molecules can readily accept electrons. Electron acceptors are important components in molecular electronic devices and solar cells, and, therefore, C18 is added to the list of organic electron acceptors that can be potentially useful in photovoltaics.

Electro- and Photocatalytic CO2 to CO Reduction Mechanism with Cobalt Complexes

The burning of fossil fuels is causing a global climatic emergency. In order to solve this crisis, is very important to improve the efficiency of the production of renewable energies by transforming CO2 into carbon-based fuels. In this report, the member of the DIMOCAT Josep M. Luis in collaboration with the Julio Lloret group, determined the mechanism and bottlenecks of the CO2 reduction reaction with a model cobalt catalyst. The theoretical calculations, in combination with in situ measurements, pinpointed an elusive cobalt(I) carbonyl intermediate, which is formed very early in the reaction and is responsible for one of the most problematic bottlenecks in the CO2 reduction process. The mechanistic studies allowed the identification the bottlenecks of the reaction and the design of a photocatalytic strategy to break the carbonylic compounds  and then strongly improve the efficient of the catalytic reduction of the CO2.

Sergio Fernández, Federico Franco, Carla Casadevall, Vlad Martin-Diaconescu, Josep M. Luis, Julio Lloret-Fillol.

“A Unified Electro- and Photocatalytic CO2 to CO Reduction Mechanism with Aminopyridine Cobalt Complexes”

J. Am. Chem. Soc. 2019, ASAP



Visit of Kamila Pruszkowska

Kamila Pruszkowska is a PhD student supervised by Prof. Michal Cyranski in the University of Warsaw . She has been working in our group for the last six weeks working in the study of the 1,2-bis(4-methylbenzoylvinylamino)ethane and Ni (II) 1,3-bis(4-methylbenzoylvinylamino)propane Ni(II) complexes coordinated to pyridine, 4-dimethylaminopyridine, 4-metoxypyridine, N-methyloimidazole, and thiazole ligands. She has been financed by an HPC-Europa3 fellowship and during her stay in our group she has been supervised by Dr. Olga A. Stasyuk and Dr. Miquel Solà. We are very happy to have had her in our group! We hope she has enjoyed her stay!

Kamila in the center with Olga and Miquel