Molecular systems

Theoretical work

Ab initio and density functional orbital calculations of several molecular properties, such as structure conformational equilibrium, vertical ionisation energies, vibrational spectra, and hyperfine constants, including the effects of electron correlation, using the Gaussian 98 code and Dalton codes, will be continued for several molecules relevant in atmospheric and combustion processes, medicine and pharmacology, such as the azides,  tetrazoles, nitrones, hemoglobin and sulfur hexafluoride [1, 2].

Experimental work

Molecular experimental studies will be mainly centred in UVPES and Matrix Isolation Infrared Spectroscopy techniques, and will mainly address the azides, tetrazols and nitrones molecules [3, 4].

Within the collaboration with the mentioned Italian research groups, it will be study in the Elletra facility the core-level electronic structure of unstable free and their reaction intermediates (radicals and transients) by high-resolution X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS).

Investigation of alkaline earth metal complexation by several organic azides, by electrospray ionization mass spectrometry (ESI-MS), and by tandem mass spectrometry (MS/MS), will continue within a collaborative project with the Environmental and Biological Mass Spectrometry Group of the Universidade de Lisboa [15]. 

The setting up of a Resonance-Enhanced Multiphoton Ionization (REMPI) experimental facility will continue to extend the available research capabilities. Lasers, as excitations and ionization sources are used. The work to be performed falls into two categories: REMPI spectroscopic studies, and photodissociation studies.

References

1. R.M. Pinto, A.A. Dias, M.L. Costa, and J.P. Santos, Computational study on the ionization energies of benzyl azide and its methyl derivatives. Journal of Molecular Structure: THEOCHEM, 2010. 948: p. 15.
2.  M.L. Palma and J.P. Santos, Spin-rotation and nuclear shielding constants of sulfur hexafluoride. Molecular Physics, 2008. 106(9-10): p. 1241-1247.
3. R.M. Pinto, R.I. Olariu, J. Lameiras, F.T. Martins, A.A. Dias, G.J. Langley, P. Rodrigues, C.D. Maycock, J.P. Santos, M.F. Duarte, M.T. Fernandez, and M.L. Costa, Study of selected benzyl azides by UV photoelectron spectroscopy and mass spectrometry. Journal of Molecular Structure, 2010. 980(1-3): p. 163-171.
4. J.M. Dyke, G. Levita, A. Morris, J.S. Ogden, A.A. Dias, M. Algarra, J.P. Santos, M.L. Costa, P. Rodrigues, M.M. Andrade, and M.T. Barros, Contrasting Behavior in Azide Pyrolyses: An Investigation of the Thermal Decompositions of Methyl Azidoformate, Ethyl Azidoformate and 2-Azido-N, N-dimethylacetamide by Ultraviolet Photoelectron Spectroscopy and Matrix Isolation Infrared Spectroscopy. Chemistry - A European Journal, 2005. 11(5): p. 1665-1676.
5. J.M. Dyke, G. Levita, A. Morris, J.S. Ogden, A.A. Dias, M. Algarra, J.P. Santos, M.L. Costa, P. Rodrigues, and M.T. Barros, A Study of the Thermal Decomposition of 2-Azidoacetamide by Ultraviolet Photoelectron Spectroscopy and Matrix-Isolation Infrared Spectroscopy:  Identification of the Imine Intermediate H2NCOCHNH. Journal of Physical Chemistry A, 2004. 108(25): p. 5299 - 5307.