Yago García-Rodeja Navarro joins the DiMoCat group as María Zambrano fellow

Starting 25th April 2022, Yago García Rodeja has joined the DiMoCat group as María Zambrano fellow for two years. He will be working on the aromaticity and reactivity of metalla-polycyclic aromatic hydrocarbons. Dr. García-Rodeja received his PhD in Chemistry from Complutense University of Madrid in 2018. During his PhD, he worked with Prof. Israel Fernández on understanding the reactivity of polycyclic aromatic hydrocarbons and related compounds. During his PhD, six of his works were done in collaboration with the DiMoCat group. He had postdoctoral experience at Universite de Pau et des Pays de l’Adour (UPPA) and CNRS-Universite de Pau et des Pays de l’Adour (UPPA) for 3 years.

We wish him good luck in his research work!

Issue 8 of volume 87 of the J. Org. Chem. contains the Back Cover and two manuscripts of DiMoCat group!

The Back Cover of issue number 8 of volume 87 refers to the recently published article “Successive Diels-Alder cycloadditions of cyclopentadiene to [10]CPPC60”. The work has been carried out by Gerard Pareras, Sílvia Simon, Albert Poater and Miquel Solà, all (excepte Gerard) members of the DiMoCat group of the Institute of Computational Chemistry and Catalysis of the University of Girona.  The design and original idea of the artwork are acknowledged to Miss Coral Garcia-Fernandez and Dr. Gerard Pareras. The paper can be read in the following link:

https://pubs.acs.org/doi/10.1021/acs.joc.1c03116

In the same issue, there is another paper entitled “Highly Selective Synthesis of Seven-Membered Azaspiro Compounds by a Rh(I)-Catalyzed Cycloisomerization/Diels–Alder Cascade of 1,5-Bisallenesby Jordi Vila, Miquel Solà, Anna Pla-Quintana, and Anna Roglans, all members of the DiMoCat group of the Institute of Computational Chemistry and Catalysis of the University of Girona. The paper can be read in the following link:

https://pubs.acs.org/doi/10.1021/acs.joc.2c00065

Prof. Slavko Radenković, visitor of the DiMoCat group

From 10 to 28 January, Prof. Slavko Radenković from the University of University of Kragujevac visited our research group to work with Prof. Miquel Solà. His research consisted in the determination of whether Baird’s rule is obeyed in boron clusters and on the aromaticity and singlet-triplet energy gap of metalla-acenes. It was a pleasure to have Slavko in our group for the last three weeks. He is not only a great researcher but also a quite good football player!

DiMoCat group has recently been added as part of the XRE4S, a Catalan R+D+i Network Energy for Society.

XRE4S is a multidisciplinary and transversal ecosystem that gathers the expertise in the energy field on the main universities and research centers in Catalonia. The main goal is to promote the technology transfer and valorisation of energy technologies to industry and society. Actually, XRE4S involves 39 research groups in 14 academia centers with more than 500 researchers. This project is co-financed by the European Regional Development Fund of the European Union in the framework of the ERDF.

DiMoCat group is an interdisciplinary group of research of the IQCC of the University of Girona led by Prof. Miquel Solà and Prof. Anna Roglans. The DIMOCAT has a theoretical and computational section and another section devoted to experimental work. Actually, the DiMoCat group is constituted by 30 researchers: 2 full professors, 1 emeritus, 6 associate professors, 4 post-docs and 17 PhD students. One of the main research lines is: research into perovskite solar panels as environmental alternative to silicon solar panels due to their low cost, and being lighter and more flexible. DIMOCAT wants to research in renewable energy as one of the greatest challenges facing humanity in the fight against climate change. Now, University of Girona has 4 groups in the XRE4S (LEQUIA, eXiT, GREFEMA and DIMOCAT).

Prof. Dr. Oscar Jiménez-Halla, former PhD student of DiMoCat group, promoted to the highest research level in Mexico

On 12th January 2022, Prof. Dr. Oscar Jiménez-Halla of the University of Guanajuato has been promoted to the highest research level in Mexico, the so-called “Investigador Nacional Nivel III”, for his leadership in the academic community of the country, as well as for his participation in the formation of the scientific community.
Congratulations Oscar! We are proud of you!!

Electron transfer in a doubly curved nanographene upon supramolecular complexation of C60

In this work, we describe the formation of supramolecular complexes between fullerene C60 and a molecular nanographene endowed with both positive and negative curvatures. The presence of a corannulene moiety and the saddle shape of the molecular nanographene allows the formation of complexes with 1:1, 1:2, and 2:1 stoichiometries. The association constants for the three possible supramolecular complexes are determined by 1H NMR titration. Furthermore, the stability of the three complexes is calculated by theoretical methods that also predict the photoinduced electron transfer from the curved nanographene to the electron acceptor fullerene C60. Time-resolved transient absorption measurements on the ns-time scale shows that the addition of C60 to nanographene solutions and photo-exciting them at 460 nm lead to the solvent-dependent formation of new species, in particular the formation of one-electron reduced form of C60 in benzonitrile is observed.

The work has been done in collaboration with the groups of Prof. Nazario Martín who synthesized the nanographene and the complexes and Prof. Dirk Guldi who performed the time-resolved transient absorption measurements. Calculations were performed in the DiMoCat group by Dr. Anton Stasyuk, Prof. Alexander Voityuk and Prof. Miquel Solà.

The paper can be read in Angew. Chem. journal through the following link:

https://onlinelibrary.wiley.com/doi/epdf/10.1002/anie.202112834

The editor classified the paper as a hot paper!

Karolina Urbanowicz, PhD visitor at the DiMoCat group

On 19th June 2021, Karolina Urbanowicz started a visit of six weeks to the DiMoCat group financed by HPC-Europa3. The research project of Karolina, which is supervised by Dr. Antony J. Stasyuk and Prof. Miquel Solà, is primarily aimed at the investigation of conformational-property landscape in triplet photosensitizers derived from metal-free organoboron complexes with semi-rigid spiro architecture and boron atom separating donor and acceptor parts of the molecule. These systems are very effective photocatalysts in the oxidation reactions mediated by singlet oxygen. We expect that understanding of their nature will lead to new opening in the field of metal-free photosensitizers with potent application in catalysis, photodynamic therapy or cancer treatment and antimicrobial photodynamic therapy.

We wish Karolina good luck and great successes in her project!

From left to right, Karolina, Anton and Miquel in the IQCC.

An unprecedented π-electronic circuit involving an odd number of carbon atoms in a grossly warped non-planar nanographene

Aromaticity in macrocycles has been less studied than aromaticity in small polycyclic aromatic hydrocarbons (PAHs). In the work carried out by Dr. Álvaro Muñoz Castro from the Grupo de Química Inorgánica y Materiales Moleculares of the Universidad Autónoma de Chile and by Sílvia Escayola, Dr. Albert Poater, and Prof. Miquel Solà from the DiMoCat group of the Institute of Computational Chemistry and Catalysis of the University of Girona, the authors analyze the most efficient circuits for π-delocalization in a grossly warped nanographene (C80H30), containing five- and seven-membered rings inserted into a six-membered mesh. DFT calculations of different aromaticity indices (FLU, HOMA, EDDB, and ring currents) indicate that one of the two most favorable circuits for π-electron delocalization formally has 50 π-electrons abiding by Hückel’s rule, whereas the second one formally has 75 π-electrons and, remarkably, it does not follow any of the known rules of aromaticity. The nanographene studied display both local aromaticity in the external six-membered rings and macrocyclic aromaticity in the 50 amd 75 π-electrons circuit. This is the first time that a π-electronic circuit has an odd number of electrons, and also that the circuit involves cross-conjugated pathways (ie they do not have alternating single and double bonds).

This finding has been highlighted by Chemistry World, as can be seen in the following link.

S. Escayola, A. Poater, A. Muñoz-Castro* and M. Solà*. An unprecedented π-electronic circuit involving an odd number of carbon atoms in a grossly warped non-planar nanographene. Chem. Commun., 2021, DOI: 10.1039/D1CC00593F

Hückel-Baird Hybrid Aromatic Character of Pro-Aromatic Quinoidal Compounds

A recent paper (Kim et al. Nature Commun. 2019, 10, 4983) claims that there is a double charge transfer in the first singlet excited singlet state in TMTQ (an oligomer composed of a central 1,6-methano[10]annulenes, M10A, and 5-diacyanomethyl-thiophene exocyclic groups, see Figure 1) that is stabilized by the Baird aromaticity acquired by the central M10A ring. In a previous work (Jorner et al. Chem. Eur. J. 2016, 22, 2793), some of us found that the charge transfer in the first excited singlet and triplet states in TMTQ is minor and that the central ring in these low-lying excited states is a Hückel-Baird hybrid with a ca. 85% of Hückel and 15% of Baird character. In the light of the new existing experimental data, Claire Tonnelé and Prof. Henrik Ottosson of the Uppsala University, Dr. David Casanova and Dr. Eduard Matito of the Donostia International Physics Center (previous DiMoCat member), and Sílvia Escayola, Dr. Albert Poater, and Prof. Miquel Solà members of the DiMoCat group of the Institute of Computational Chemistry and Catalysis of the University of Girona decided to reinvestigate the problem using (time-dependent) density functional theory methods. We considered not only TMTQ but also a series of symmetrically substituted conjugated rings that can generate Baird aromaticity in the lowest-lying excited states. This work shows that the interpretation by Kim et al. needs to be revised because low-lying excitations of symmetrically substituted conjugated rings including TMTQ hold very weak charge transfer character. Our computational results also allow us to establish general guidelines for the rational design of molecules with excited state Hückel/Baird aromaticity in pro-aromatic quinoidal compounds We found that high Baird character of the central ring is achieved only with anionic and small conjugated central rings with electron donating groups as substituents and small exocyclic groups with electron withdrawing substituents. Our study aims to warn about the need to make correct interpretations of the experiments in this growing area of research, as only then can the excited state aromaticity concept develop in a useful tool for the design of high-performance organic electronic devices.

Figure 1. Quinoidal, diradical, and ionic resonance structures of importance for TMTQ (10R-T) involved in the description of S0, S1, and T1 states.

 

Escayola, C. Tonnelé, E. Matito, A. Poater, H. Ottosson*, M. Solà* and D. Casanova*. Guidelines for Tuning the Excited State Hückel-Baird Hybrid Aromatic Character of Pro-Aromatic Quinoidal Compounds. Angew. Chem. Int. Ed., 2021, DOI: 10.1002/anie.202100261.