biostudies-literatureVan Stappen CDeutsche ForschungsgemeinschaftPeter und Traudl Engelhorn StiftungIcelandic Centre for ResearchIMPRS-RECHARGEMax-Planck-Gesellschaft5005-5081https://www.ebi.ac.uk/biostudies/studies/S-EPMC7318057biostudies-literatureUnknown120(12)Nitrogenases are responsible for biological nitrogen fixation, a crucial step in the biogeochemical nitrogen cycle. These enzymes utilize a two-component protein system and a series of iron-sulfur clusters to perform this reaction, culminating at the FeMco active site (M = Mo, V, Fe), which is capable of binding and reducing N₂ to 2NH₃. In this review, we summarize how different spectroscopic approaches have shed light on various aspects of these enzymes, including their structure, mechanism, alternative reactivity, and maturation. Synthetic model chemistry and theory have also played significant roles in developing our present understanding of these systems and are discussed in the context of their contributions to interpreting the nature of nitrogenases. Despite yeaChemical reviewsThe Spectroscopy of Nitrogenases.PMC7318057162880051DE 1877/1-1BI 2198/1-1Bjornsson RDeBeer SHenthorn JTBirrell JACutsail GEDecamps LVan Stappen CfalseThe Spectroscopy of Nitrogenases.Nitrogenases are responsible for biological nitrogen fixation, a crucial step in the biogeochemical nitrogen cycle. These enzymes utilize a two-component protein system and a series of iron-sulfur clusters to perform this reaction, culminating at the FeMco active site (M = Mo, V, Fe), which is capable of binding and reducing N₂ to 2NH₃. In this review, we summarize how different spectroscopic approaches have shed light on various aspects of these enzymes, including their structure, mechanism, alternative reactivity, and maturation. Synthetic model chemistry and theory have also played significant roles in developing our present understanding of these systems and are discussed in the context of their contributions to interpreting the nature of nitrogenases. Despite yea2020-01-01T00:00:00Z2020 Jun2025-06-01T02:42:42.967Z2025-06-01T02:42:42.967ZS-EPMC73180573223773910.1021/acs.chemrev.9b00650