Are 3D and 2D aromaticies like oil and water? The case of benzocarborane derivatives and 3D/3D fusions

In this work, we show that while is it very usual to find examples of 2D/2D aromaticity and not so usual but still possible to have 3D/3D aromatic compounds, it is very difficult to generate 2D/3D aromatic systems. Such a 3D/2D aromatic combination is not possible due to the ineffective overlap between the π-MOs of the planar species and the n+1 molecular orbitals in the aromatic cage that deter an effective electronic delocalization between the two fused units.

Experimental studies were done by the group of Prof. Francesc Teixidor and Clara Viñas at Institute of Materials Science (ICMAB-CSIC) and calculations were performed in the IQTCUB institute by Prof. Jordi Poater and in the DiMoCat group by Prof. Miquel Solà.

The study was recently published in Nature Communications:

 Poater, C. Viñas, M. Solà* and F. Teixidor*.

3D and 2D aromaticies like oil and water in the case of benzocarborane derivatives.

Nature Commun., 13 (2022) 3844, DOI: 10.1038/s41467-022-31267-7. IF 17.694, Q1. Open Access.

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 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