Final Report Summary - CACOPHOS (Cage Complexes With Phosphonates)
The project worked extremely well during the two years that Dr Kandasamy was in Manchester. Four areas should be highlighted.
(i) Dr Kandasamy has shown that very simple metal precursors can be used in the reactions with phosphonates, for example ß-diketonates. These serve to block sites on the metal ions present and hence control the symmetry and stoichiometry of the products. The approach looks extremely promising as a method for producing high symmetry compact cages by design.
The approach works well with copper, and a paper is about to be submitted to Chemical Communications describing the synthesis of a paramagnetic equivalent of the Keggin ion.
Work on heterometallic 3d-4f cages led to new Cu-Gd and Cu-Dy cages. The former show a very high magnetocaloric effect, while the latter a new single molecule magnets. This work was published in a special issue of Dalton Transactions on molecular magnetism.
(ii) Dr Kandasamy has worked well supervising visitors and PhD students. He has collaborated with a Chinese student visitor (Miss Dan Liu) to extend dramatically manganese phosphonate cages. We have made new manganese cages ranging as large as a cage containing twenty-three Mn centres. Preliminary studies show that several of these cages are single molecule magnets.
Dr Kandasamy also completed work by other PhD students, leading to new cage cobalt and iron phosphonate complexes.
(iii) Reactions with nickel precursors have shown that phosphonates can condense in very mild conditions to produce RPO2(O)PO2R ligands; these ligands have only been seen once previously and on that occasion they were made under forcing conditions. This could open up a new class of polyoxo donor ligands. The reason why the pyrophosphonate is forming is not clear. This work has been written up and is about to be submitted to Dalton Transactions.
(iv) A major undertaking during the final part of Dr Kandasamy's research period in Manchester was to write an authoritative account of the synthesis of paramagnetic metal phosphonates. This work will appear in the last part of 2011 as part of a new book on metal phosphonates, which is edited by Prof. Abraham Clearfield and Prof. Kostas Demadis, published by the RSC. Dr Kandasamy largely wrote the text and prepared all the figures for this long review article. The production of this article showed remarkable maturity and judgement from a young research worker.
A summary of the progress of the researcher training activities
Dr Kandasamy has been fully-trained in X-ray crystallography and can now collect, solve and refine X-ray data sets. He is also capable of training other co-workers in this technique. He has been passing on his considerable synthetic skills to other members of the group and is already a very valuable co-worker and colleague. Training in SQUID magnetometery and EPR spectroscopy took place in 2010.
(i) Dr Kandasamy has shown that very simple metal precursors can be used in the reactions with phosphonates, for example ß-diketonates. These serve to block sites on the metal ions present and hence control the symmetry and stoichiometry of the products. The approach looks extremely promising as a method for producing high symmetry compact cages by design.
The approach works well with copper, and a paper is about to be submitted to Chemical Communications describing the synthesis of a paramagnetic equivalent of the Keggin ion.
Work on heterometallic 3d-4f cages led to new Cu-Gd and Cu-Dy cages. The former show a very high magnetocaloric effect, while the latter a new single molecule magnets. This work was published in a special issue of Dalton Transactions on molecular magnetism.
(ii) Dr Kandasamy has worked well supervising visitors and PhD students. He has collaborated with a Chinese student visitor (Miss Dan Liu) to extend dramatically manganese phosphonate cages. We have made new manganese cages ranging as large as a cage containing twenty-three Mn centres. Preliminary studies show that several of these cages are single molecule magnets.
Dr Kandasamy also completed work by other PhD students, leading to new cage cobalt and iron phosphonate complexes.
(iii) Reactions with nickel precursors have shown that phosphonates can condense in very mild conditions to produce RPO2(O)PO2R ligands; these ligands have only been seen once previously and on that occasion they were made under forcing conditions. This could open up a new class of polyoxo donor ligands. The reason why the pyrophosphonate is forming is not clear. This work has been written up and is about to be submitted to Dalton Transactions.
(iv) A major undertaking during the final part of Dr Kandasamy's research period in Manchester was to write an authoritative account of the synthesis of paramagnetic metal phosphonates. This work will appear in the last part of 2011 as part of a new book on metal phosphonates, which is edited by Prof. Abraham Clearfield and Prof. Kostas Demadis, published by the RSC. Dr Kandasamy largely wrote the text and prepared all the figures for this long review article. The production of this article showed remarkable maturity and judgement from a young research worker.
A summary of the progress of the researcher training activities
Dr Kandasamy has been fully-trained in X-ray crystallography and can now collect, solve and refine X-ray data sets. He is also capable of training other co-workers in this technique. He has been passing on his considerable synthetic skills to other members of the group and is already a very valuable co-worker and colleague. Training in SQUID magnetometery and EPR spectroscopy took place in 2010.
