WATOC Award Winners: Manjinder Kour, Maxime Ferrer and Sergio Pérez Tabero

 

In our final set of interviews from the 12th Triennial Congress of the World Association of Theoretical and Computational Chemists (WATOC 2020), PeerJ Physical Chemistry recently spoke to PeerJ Award winners Manjinder Kour, Maxime Ferrer and Sergio Pérez Tabero about their research.

You can read the other WATOC 2020 PeerJ Award winner interviews using the below links.

 

Dr. Manjinder Kour Postdoctoral Research Associate at Montana State University, USA. 

Can you tell us a bit about yourself and your research interests?

I am working in the group of Prof. Eric Boyd at Montana State University (MSU), USA. I am both a computational and experimental chemist. I thrive on tackling problems with relevance to practical applications that have clear public benefit. My PhD research included the design, controlled synthesis, purification, characterization of structurally controlled compounds and, quantum calculation to decipher the reactivity, reaction mechanism, diastereoselectivity, thermodynamic stability, molecular properties, coordination, and spectroscopy of newly synthesized organic compounds and organometallic complexes. During my first postdoc, I used a variety of approaches to relate molecular chirality, reactivity, coordination, excited states, fundamental interactions, photochemistry, catalysis, and reaction mechanism to the molecular properties of compounds. Currently, I am working on iron-sulphur coordination compounds at MSU. The goal of this project is to uncover the mechanisms that underpin how methanogenic archaea reduce pyrite (FeS2) and assimilate reduction products, including metals of national strategic importance to meet biosynthetic demands. Under the supervision of my external supervisor, Prof. Robert K. Szilagyi at University of British Columbia – Okanagan, Canada, I work closely with a group of microbiologists, geochemists, biochemists, and surface scientists for this project.

What first interested you in this field of research?

Pyrite (FeS2) is the most abundant sulfide mineral in the Earth’s crust and is common in environments inhabited by methanogenic archaea. FeS2 can be reduced by methanogens, yet the chemical transformations that take place at the surface of FeS2 during reduction are not clear. To bridge this critical knowledge gap, I am developing fundamental structural models and exploring the chemical space that connects the abiotic pyrite reduction and dissolution reactions to biotic FeS cluster acquisition in methanogens. Using state-of-the art imaging, spectroscopic, and computational approaches, we are probing the reaction mechanisms, rates, and chemical transformations at the surface of FeS2 during reduction, focusing on molecular interactions at the mineral-cell interface. Our emphasis is on the computational investigation of iron-sulphur coordination compounds, clusters, nanoparticles and mineral surfaces, and synchrotron spectroscopy of inorganic and organometallic complexes involved in FeS2 reduction. Information from modeling and experiments will ultimately be used as a framework to improve the recovery of trace metals of bioenergy and national security relevance from pyritic ores.

Can you briefly explain the research you presented at WATOC?

At WATOC 2020, I presented my work on the development of atomic-scale models for low temperature pyrite reduction reactions. We developed models for FeS2 , Fe1-xS, and bulk, surface, and nanoparticulate FeS mack /FeS (aq) phases . We used the bulk mineral structures for validation of the computational level of theory. The mineral surface models were created to feature the most reactive crystal faces as determined experimentally. A new nanoparticle construction strategy was presented that considers the rectangular, pentagonal, and hexagonal building blocks in FeSmack , FeS2 , and Fe1-xS, respectively. The nanoparticle models as molecular maquettes of mineral surfaces will provide us with the versatility to describe geometric and electronic structure changes, energetic consequences of electrochemical reduction, small molecule coordination and electron transfer, surface decomposition, and HS- release along the FeS2 → Fe1-xS → FeS mack continuum.

What are your next steps?

Computational models as virtual nanoreactors will be utilized to determine the mechanism of abiotic reductive dissolution of pyrite through proposed pyrrhotite intermediate and formation of mackinawite-like nanoparticles. The continuation of the work will involve the investigation of heterometal substitution as experimentally shown for the considerable increased reactivity of pyrite nanoparticles when they are doped with Ni ion.

 

Maxime Ferrer Ph.D. candidate at Universidad Autónoma de Madrid, Spain. 

Can you tell us a bit about yourself and your research interests?

I am a French chemist. After obtaining a degree in general chemistry in Toulouse, I decided to explore the world of computational chemistry, as well as life in Spain. After falling in love with the non-covalent interactions and Madrid, I started my Ph.D. in the Instituto de Química Médica (CSIC) with Pr. Ibon Alkorta. Nowadays, my research is mainly based on the study of Frustrated Lewis Pairs and their ability to capture carbon dioxide molecules.

What first interested you in this field of research?

Frustrated Lewis Pairs (FLP) are based on a principle that really fascinates me. Take two molecules that usually interact which each other to form a stable adduct that precipitates and nothing else happen. Now, forbid the possible contact between the two moieties, frustrate them! You obtain a totally different reactivity. You system is now able to interact with a third molecule, like for example with H2 or CO2. Knowing that the increase of the CO2 concentration in the atmosphere is a real concern, and that FLP are metal free systems able to capture CO2, and to transform it, they seem to be a very good solution to deals with this huge problem.

Can you briefly explain the research you presented at WATOC?

At WATOC I presented a very recent study that we carried out in our lab (https://doi.org/10.1002/cphc.202200204). If we want to capture CO2 with FLP, we want them to form a stable adduct. If we want to activate the CO2, we want the adduct to be relatively stable, but not too much, because else; it will not react. We were then interested in determining what were the parameters of the FLP that can, a priori, predict the stability of the adduct. We based this study on a very particular type of systems. They consist in a cyclic FLP presenting a delocalized π-system. They are anthracene in which ones the carbon atoms in position 9 and 10 have been substituted by one phosphorus and one boron atoms. They are called 5,10-Disubstituted Dibenzophosphaborine. By changing the nature of the substituent on the boron and phosphorus atoms we highlighted that the stability of the adduct was governed by the acidity and basicity of the Lewis acid and Lewis base. However, due to the delocalization of the π-electrons, it was not possible to use too strong acid or base. Indeed, a too strong acid will attract the surrounding electrons, especially the one of the base, reducing its basicity and thus its reactivity.

What are your next steps?

By accessing the stability of the adduct, we were able to control in a way the thermodynamic of the reaction. We are able to obtain an adduct that is more stable then the reactants, and thus to obtain a reaction more or less favorable depending on our needs. The next step will be to control the kinetics of the reaction. The main question here is: how can I control or predict the stability of the transition state? At which step of the reaction is the activation barrier set? I really hope to be able to bring you this answer soon.

You can follow Maxime on Twitter: @MaximeFERRER7

 

Sergio Pérez Tabero Ph.D. candidate at Universidad Autónoma de Madrid, Spain. 

Can you tell us a bit about yourself and your research interests?

My first steps in research was in Santiago de Compostela (Spain), working with Saulo A. Vazquez and Emilio Martinez Nuñez coming to publish a paper under the title “New Approach for Correcting Noncovalent Interactions in Semiempirical Quantum Mechanical Methods: The Importance of Multiple-Orientation Sampling” in the Journal of Chemical Theory and Computation. Then I started my PhD at Madrid with Manuel Alcamí Pertejo and Ana Martín Somer working on fragmentation doing molecular dynamics using different programs like VENUS and Gaussian.

What first interested you in this field of research?

Our first aim is the simulation of mass spectra, focused on pesticides, using different types of theoretical methods of calculations but with a special emphasis on semiempirical quantum methods.

Can you briefly explain the research you presented at WATOC?

This work is a parallel project from my main work. While we were studying the protonated form of a group of pesticides for the study of mass spectrums we realized the potential of different protomers in different environments, in our case gas phase and water, and how it could be interesting to understand how this kind of these molecules works as pesticides and their environmental impact. We use CREST, CENSO and Gaussian programs for this job with very promising results but we still have a lot to explore.

How will you continue to build on this research?

Sincerely I don’t know. I’m still new to this field but I would like to explore the universe of pesticides or drugs to better understand how their chemistry works and try to answer some current questions related to the environment, medicine or industry under the prism of theoretical chemistry.

 

 

 

You may also like...