The activation of the nitrogen molecule has been a long-standing challenge in inorganic chemistry. Although Nature appears to have found a convenient route to activate the strong N-N triple bond at ambient temperatures and pressures, the mechanism employed by the natural FeMo and FeV cofactors is still under scrutiny. Besides the well-known Haber-Bosch-process, many molecular complexes capable of N2 activation have been synthesized, some of which target the production of ammonia while others aim at the incorporation of the nitrogen atoms into value-added products. Turnover for these catalysts usually relies on thermal energy input.The direct oxidation of nitrogen to nitrate would improve the redox economy of the overall transformation, avoid the waste of fossil H2, and holds promise for enormous energy savings. This talk will explore the thermodynamic conditions for a direct oxidation route as well as plausible intermediates and reaction paths.A relatively unexplored route in nitrogen fixation is the use of light. By promoting a transition metal catalyst into an electronically excited state, the N2 bond can either be weakened and made more basic to facilitate protonation, or even be photosplit completely leading to metal nitride complexes as versatile platforms for further syntheses. Several synthetic examples for nitrogen photoactivation are known, however the underlying photophysical and photochemical processes are not fully resolved. In this talk, recent progress in the quantum chemical description of nitrogen photoactivation will be presented.
Interessierte sind herzlich willkommen!
Prof. Dr. Carola Schulzke
PD Dr. Heike Kahlert, Vorsitzende des Ortsverbandes der GDCh
Institut für Biochemie
Sekretariat Prof. Dr. Carola Schulzke und Prof. Dr. Mihaela Delcea
Felix-Hausdorff-Straße 4, 17489 Greifswald
Telefon +49 3834 420 4304