Research overview

Keywords ‘crystal engineering’ ‘Perl’ ‘scripting’ ‘DFT’ ‘broken symmetry’ ‘iron-sulfur cluster’ ‘computational chemistry’ ‘catalysis’

PhD Research During my PhD, I worked on several crystal engineering projects that culminated in my PhD thesis, entitled ‘Crystal Engineering of salts of 1,2-dicarbonyls and pyridinium derivatives’. In this research, I crystallised pyridinium derivatives such as picolines and aminopyridines with metal complexes of dithiooxalate and dithiosquarate to investigate the effect of changing steric parameters on the hydrogen-bonded crystal structure.

Hydrogen-bonded tapes of Nickel bis(dithiosquarate) and 4-pyridinium.
Hydrogen-bonded tapes of nickel(II) bis(dithiosquarate) and 4-pyridinium.

Postdoctoral Research

University of Bristol During the write-up period of my PhD thesis, I started a postdoctoral position with Dr. Natalie Fey in the Centre for Computational Chemistry. During this project, I worked on developing several scripts to calculated dispersion corrected energies, to carry out dispersion corrected Gaussian calculations, which at the time could not be carried out in Gaussian, and to extract geometric parameters from the ligand knowledge base (LKB) database to parameterise a new force-field. Also, using Jaguar and Gaussian, calculated minimum energy and transition state structures for the principle steps of the rhodium-xantphos-catalysed hydroformylation of propene.

 

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A few of the important steps in the rhodium-xantphos-catalyzed hydroformylation of propene, calculated using Schrodinger Jaguar.

Universidad de Buenos Aires In 2013, I started a postdoctoral position at the Universidad de Buenos Aires in Buenos Aires, Argentina. The project, crystal engineering studies of iridium-nitrosyl complexes, was carried out under the supervision of Dr. Florencia Di Salvo and Prof. Fabio Doctorovich. During this time, I carried out single crystal X-ray diffraction studies on several photoactive crystals as part of a collaboration with Prof. Germán Sciaini at the University of Waterloo, Canada. I also collaborated with Dr. Andreas Schüren on single crystal diffraction studies of iron-sulfur clusters, including carrying out broken symmetry DFT geometry optimizations, and other calculations, on the structures.

 

The crystal structure of a dianionic iron-sulfur cluster with halide ligands; in this case, iodide and chloride.
The crystal structure of a dianionic iron-sulfur cluster with halide ligands; in this case, iodide and chloride.

Published work For two papers in collaboration with the group of Prof. Neil Connelly and as part of my PhD working in the Structural Chemistry group, I collected single crystal X-ray data and solved the crystal structures of these rhodaboratrane compounds.(Blagg et al. 2009; Blagg et al. 2010) In one paper,(Fey et al. 2011) we explored the importance of dispersion in ligand–metal bond energies using Stefan Grimme’s empirical dispersion correction method.(Grimme et al. 2010) For this paper, we used structures calculated for the LKB project (Fey et al. 2006) and a Perl script to calculate the dispersion corrected energies based on Grimme’s paper.

Papers in process Currently, I am working on a crystal engineering paper investigating solvatomorphs of some iridium-dimethylsulfoxide crystal structures. Also, in collaboration with Andreas Schüren, we hope to publish the crystal structures of three iron-sulfur clusters containing mixed halide ligands, which we collected at both room and  low temperature, along with a comparison of these structures calculated by broken symmetry DFT.

 

References

Blagg, Robin J, Christopher J Adams, Jonathan P H Charmant, Neil G Connelly, Mairi F Haddow, Alex Hamilton, James Knight, A Guy Orpen, and Benjamin M Ridgway. 2009. “A Novel Route to Rhodaboratranes [Rh(CO)(PR3){B(taz)3}]+ via the Redox Activation of Scorpionate Complexes [RhLL’Tt].” Dalton Transactions , no. 40 (October): 8724–36.

Blagg, Robin J, Neil G Connelly, Mairi F Haddow, Alex Hamilton, Matteo Lusi, A Guy Orpen, and Benjamin M Ridgway. 2010. “Isomerism in rhodium(I) N,S-Donor Heteroscorpionates: Ring Substituent and Ancillary Ligand Effects.” Dalton Transactions  39 (48): 11616–27.

Fey, Natalie, Fey Natalie, Athanassios C Tsipis, Stephanie E Harris, Jeremy N Harvey, A Guy Orpen, and Ralph A Mansson. 2006. “Development of a Ligand Knowledge Base, Part 1: Computational Descriptors for Phosphorus Donor Ligands.” Chemistry – A European Journal 12 (1): 291–302.

Fey, Natalie, Benjamin M Ridgway, Jesús Jover, Claire L McMullin, and Jeremy N Harvey. 2011. “Organometallic Reactivity: The Role of Metal-Ligand Bond Energies from a Computational Perspective.” Dalton Transactions  40 (42): 11184–91.

Grimme, Stefan, Grimme Stefan, Antony Jens, Ehrlich Stephan, and Krieg Helge. 2010. “A Consistent and Accurate Ab Initio Parametrization of Density Functional Dispersion Correction (DFT-D) for the 94 Elements H-Pu.” The Journal of Chemical Physics 132 (15): 154104.

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