The work conducted was organized into five overlapping work packages (WP). The first work package, on preparation and management, included activities such as monitoring the literature on iron-catalyzed C–H activation and learning new techniques described therein (e.g. construction of optical fibers for LED NMR spectroscopic investigations). It also included other support activities such as planning experiments, ordering chemicals and equipment, ensuring safety measures in handling chemicals were followed, keeping a detailed lab journal, filling in the timesheet for the action, and preparing the career development and data management plans. WP2 involved the synthesis and characterization (a combination of spectroscopic, spectrometric, and crystallographic methods was used) of a variety of previously reported and novel iron complexes that were used either as precatalysts or as precursors for stoichiometric and catalytic reactions aiming to obtain better mechanistic understanding of the developed catalytic systems. Part of the work conducted in WP2 also involved the challenging isolation and crystallographic characterization of catalytically relevant intermediates which facilitated the construction of solid mechanistic proposals. During WP3, novel iron-catalyzed transformations were developed by screening several substrates and precatalysts. Subsequently, the reaction conditions were varied to improve the performance of the reaction in terms of yield and selectivity and to increase its sustainability by decreasing the reaction temperature (reaction optimization). With the optimized conditions in hand, the robustness of the reaction in terms of functional group tolerance was probed by performing substrate scope. The obtained products were isolated using flash column chromatography and fully characterized with nuclear magnetic resonance (NMR) and infra-red (IR) spectroscopies as well as with mass spectrometry (MS). In the fourth and most complex working package, mechanistic investigations were performed that aimed to understand the way the developed reactions operate. For this purpose, a combination of spectroscopic (NMR, IR, UV-Vis, Mossbauer, EPR) and spectrometric (LIFDI, HESI) techniques were used to profile the reactions and perform kinetic studies. The appropriate training on LIFDI mass spectrometry, HESI mass spectrometry, electron paramagnetic resonance (EPR) spectroscopy as well as Mossbauer spectroscopy was also provided to the researcher in addition to training in the advanced use of NMR instruments. Lastly, density functional calculations (DFT) were performed in collaboration with members of the group to explore alternative mechanistic pathways that are difficult to probe experimentally.
Part of the work described above (WP5) is now published in ACS catalysis (Cyclometallated Iron(II) Alkoxides in Iron-Catalyzed C–H Activations by Weak O-Carbonyl Chelation) while the rest has been submitted to Nature Catalysis, both high impact journals. In addition, the work has been presented at three conferences (two in Athens and one in Göttingen) and the ACS catalysis publication has already been cited twice. The researcher was also invited to the Moraitis school in Athens to discuss the project and research in the field of chemistry with students. In addition, results were also disseminated within the group through presentations and informal discussions with colleagues.
