PCAP · Photocatalytic Cluster Complexes for Artificial Photosynthesis Applications

Photocatalytic Cluster Complexes for Artificial Photosynthesis Applications

The primary focus of the consortium set up between the groups from the UK, Moldova and Romania was the production of complexes as water oxidation catalysts. It was apparent from the start that other avenues of research would be available covering such themes as dye-sensitised solar cells, coordination polymers and redox catalysts. Rather than being restrictive researchers were encouraged to explore these other topics as part of the overall project, and promote their research findings at meetings, within seminars and peer-reviewed publications. Another important aspect of the project was to build a research community of next generation chemists needed in artificial photosynthesis research. Certainly for this last point the exchange visits have allowed a good working arrangement to be set up; the aim now is to exploit the new consortium and apply for further funding to carry out more research. The scientific part of the project was successful and highlighted are brief summaries of the research work: (i) Manganese-Calcium Clusters. By way of careful control of reagents and metal ions we have prepared several new complexes and determined their crystal structures. An especially appealing structure reveals a calcium ion rod-like arrangement which is decorated with manganese complexes. Variable temperature magnetic, electrospray mass spectrometry and electrochemistry studies are consistent with the polymer breaking apart in solution. (ii) Coordination Polymers. Using ligands initially designed for complexing to manganese ions a plethora of other transition metal ions were tested in the presence of carboxylic acids. Crystal structures of several complexes were collected, revealing water pockets and cavities for gas sorption. For complexes containing multiple paramagnetic ions spin-spin interactions were measured using a SQUID spectrometer. Unfortunately, no single molecule magnet behaviour was observed. (iii) Ferrocene Porphyrin Sensitisers and Redox Active Complexes. Noting that redox active molecular systems are invaluable for activation of small molecules, a secondary part of the project involved the preparation of porphyrin compounds and ligands based on terpyridine. The ferrocenyl-porphyrin derivative was adapted for application in solar cells applications. Although the solar cell performance of the molecular system was poor a detailed study (electrochemistry, theoretical, excited state dynamics) was insightful, revealing fast excited state quenching. A summary of projects presented by PhD students visiting the UK can be found at http://research.ncl.ac.uk/mpl/members/index.php As part of the exchange programme senior academics visited both Romania and the UK. An especially important exchange was that of Prof. Gheorghe Duca (Government Minister for Science-Moldova) to the UK. Meetings with Executive Officers at Newcastle (Pro-Vice-Chancellor (Learning and Teaching-Professor Suzanne Cholerton, Pro-Vice-Chancellor (Science, Agriculture and Engineering-Professor Steve Homans) have put in place the beginnings for closer collaboration. Exchange visits of executive officers to Moldova will hopefully take place in the near future to promote socioeconomic development. During the project seminars and three meetings were held to update the progress and encourage the PhD students to disseminate their work. The final meeting in Al.I.Cuza University brought together all staff involved in the PCAP project. Senior academic staff also presented seminars on their specialized research topics during visits to host universities. For example, Professor Turta (Moldova) presented a three lecture class on Mössbauer spectroscopy at Newcastle University. Visiting staff also used the exchange to promote collaboration with staff from other universities. Dr Sergiu Shova (Moldova) , for instance, has set up a working dialogue with crystallography staff at Durham University (UK). Overall the researchers have benefitted from the exchange programme by allowing access to facilities that otherwise were not available at their own university. The X-ray facilities at Newcastle were extensively used and around 50 structures were collected over the three years. The collection of Mössbauer spectra using facilities at the Academy of Sciences of Moldova by the group from Newcastle University has been invaluable in characterising iron complexes and ferrocene derivatives. Researchers have also benefited from utilising the technique of microwave synthesis through the exchange visit to Al.I.Cuza University (Romania).

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз