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Solvation effects on photo-induced Metal-Activated Oxidative-Addition Reactions of Hydrocarbons and Halocarbons

Final Report Summary - METOXAD (Solvation effects on photo-induced Metal-Activated Oxidative-Addition Reactions of Hydrocarbons and Halocarbons)

European Reintegration Grants (ERG) final term report
Grant agreement No. 203885
METOXAD project summary by Dr Martin A. Collier
Date: 10 March 2011

Stage 1: production of sodium(Ca)/rare-gas(RG) solids

Stage 1 of the METOXAD project, the production and characterisation of rare gas solids doped with 'isolated' calcium atoms, has been accomplished. High-quality Ca/Rg films have been deposited at 10 K. Absorption spectra recorded following sample production have allowed the assignment of atomic transitions to the 1P and 1D excited states of atomic calcium.

Deviations

1. Initially it was proposed to deposit at 12 K. However a lower deposition temperature of 10.5 K was achieved following the redesign and installation of a pre-existing radiation shield on the cryostat. The lower temperature has allowed easier identification of calcium absorption bands.
2. It was proposed to produce calcium vapour by laser ablation of the bulk metal from a rotating rod. Due to financial constraints, a Knudsen-cell, high-temperature oven was employed instead. See note regarding project finances below.

Installation of the Knudsen cell allowed an investigation of the luminescence spectroscopy of atomic sodium. The results of this were published by the Maynooth Group in collaboration with Patrick de Pujo of Laboratoire Francis Perrin (CNRS URA 2453, CEA Saclay, France) and Claudine Crepin of Laboratoire de PhotoPhysique Moleculaire (CNRS UPR 3361, Université Paris-Sud 11, Orsay, France).

Stage 2: luminescence of solvated calcium atoms

Stage 2, characterisation of rare-gas solids doped with 'isolated' calcium atoms, has for the most part been accomplished. The luminescence spectroscopy recorded has allowed the effect of inert RG solvation on the metal atom to be determined.

The 1D luminescence has been shown to depend on the rare-gas host (solvent) and the site / cavity-size available to the metal atom within the solid. Recent high-resolution one-dimensional (1D) measurements have indicated the presence of weak crystal field effects.

The extension of the luminescence measurement to calcium atoms in reactive halocarbon and hydrocarbon matrices is still on-going. Early results indicate novel thermal Ca + CH3F reactivity occurring at 10 K.

The observation of weak crystal field splitting of Ca atoms prompted a more detailed analysis of the existing manganese data leading to two recent publications.

Deviations

The novel thermal reaction Ca + CH3F observed at 10 K has hampered subsequent spectroscopic investigations.

Stage 3: step-scan Fourier transform infrared (FTIR) calcium and molecule reactions

Rare-gas matrices containing calcium and the molecule of interest have been produced for investigation using infrared spectroscopy. However no evidence of the Ca (1S) + CH3F van der Waals reaction precursor (Ca-CH3F) has been observed to date.

Deviations

Low concentrations of the precursor complex were anticipated in the initial project outline. It was proposed to increase the concentration of precursor substantially with a pulsed ablation source. The projected ablation source would have allowed direct injection of the pre-formed gas-phase cluster into the rare-gas solvent. Financial constraints have not allowed the design and construction of the ablation source.

Researcher training and integration activities

The researcher Dr Martin Collier has also been engaged in contract and part-time teaching as well as supervision of first to final year undergraduate and postgraduate students within the Department of Chemistry at the National University of Ireland, Maynooth.

Deviations

The proposed application by the researcher and the host department for a tenure-track position under the Stokes Professorship and Lectureship Programme of Science Foundation Ireland (SFI) 2007 did not proceed. The researcher's application was turned down within the host department.

Project finances

No salary contribution was sought on application for the ERG grant.

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