Collaborations in Inorganic Chemistry

I began my path in computational chemistry while I still was an undergraduate student, working on my thesis under professor Cea at unam, synthesizing main group complexes with sulfur containing ligands. Quite a mouthful, I know. Therefore my first calculations dealt with obtaining Bond indexed for bidentate ligands bonded to tin, antimony and even arsenic; yes! I worked with arsenic once! Happily, I keep a tight bond (pun intended) with inorganic chemists and the recent two papers published with the group of Prof. Mónica Moya are proof of that.

In the first paper, cyclic metallaborates were formed with Ga and Al but when a cycle of a given size formed with one it didn’t with the other (fig 1), so I calculated the relative energies of both analogues while compensating for the change in the number of electrons with the following equation:

Fig 1

Imagen1

Under the same conditions 6-membered rings were formed  with Ga but not with Al and 8-membered rings were obtained for Al but not for Ga. Differences in their covalent radii alone couldn’t account for this fact.

ΔE = E(MnBxOy) – nEM + nEM’ – E(M’nBxOy)                     Eq 1

A seamless substitution would imply ΔE = 0 when changing from M to M’

Imagen2.jpg

Hipothetical compounds optimized at the B3LYP/6-31G(d,p) level of theory

The calculated ΔE were: ΔE(3/3′) = -81.38 kcal/mol; ΔE(4/4′) = 40.61 kcal/mol; ΔE(5/5′) = 70.98 kcal/mol

In all, the increased stability and higher covalent character of the Ga-O-Ga unit compared to that of the Al analogue favors the formation of different sized rings.

Additionally, a free energy change analysis was performed to assess the relative stability between compounds. Changes in free energy can be obtained easily from the thermochemistry section in the FREQ calculation from Gaussian.

 

 

This paper is published in Inorganic Chemistry under the following citation: Erandi Bernabé-Pablo, Vojtech Jancik, Diego Martínez-Otero, Joaquín Barroso-Flores, and Mónica Moya-Cabrera* “Molecular Group 13 Metallaborates Derived from M−O−M Cleavage Promoted by BH3” Inorg. Chem. 2017, 56, 7890−7899

The second paper deals with heavier atoms and the bonds the formed around Yttrium complexes with triazoles, for which we calculated a more detailed distribution of the electronic density and concluded that the coordination of Cp to Y involves a high component of ionic character.

This paper is published in Ana Cristina García-Álvarez, Erandi Bernabé-Pablo, Joaquín Barroso-Flores, Vojtech Jancik, Diego Martínez-Otero, T. Jesús Morales-Juárez, Mónica Moya-Cabrera* “Multinuclear rare-earth metal complexes supported by chalcogen-based 1,2,3-triazole” Polyhedron 135 (2017) 10-16

We keep working on other projects and I hope we keep on doing so for the foreseeable future because those main group metals have been in my blood all this century. Thanks and a big shoutout to Dr. Monica Moya for keeping me in her highly productive and competitive team of researchers; here is to many more years of joint work.

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About joaquinbarroso

Theoretical chemist in his late thirties, in love with life and deeply in love with his woman and children. I love science, baseball, literature, movies (perhaps even in that order). I'm passionate about food and lately wines have become a major hobby. In a nutshell I'm filled with regrets but also with hope, and that is called "living".

Posted on August 16, 2017, in Articles, Computational Chemistry, Inorganic Chemistry, Paper and tagged , , , , , , , , , , , , . Bookmark the permalink. 2 Comments.

  1. Inorganic chemistry collaborations can be challenging with all those heavy elements, but at the same time also very fruitful and interesting, like yours. Congratulations to you and the rest of the team 🙂

  2. Thank you for sharing this Dr Barroso. Is there a simple way of saving computational time when running such a calculation with this number of atoms, more specially a calculation containing metals?

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