This is a literature discussion based on a 2018 Inorganic Chemistry paper from the Lehnert group titled “Mechanism of N–N Bond Formation by Transition Metal–Nitrosyl Complexes: Modeling Flavodiiron Nitric Oxide Reductases“(DOI: 10.1021/acs.inorgchem.7b02333). The literature discussion points students to which sections of the paper to read, includes questions for students to complete before coming to class, and in class discussion questions. Several of the questions address content that would be appropriate to discuss in a bioinorganic course. Coordination chemistry and mechanism discussion questions are also included.
A successful student will be able to:
Evaluate structures of metal complexes to identify coordination number, geometry (reasonable suggestion), denticity of a coordinated ligand, and d-electrons in FeII/FeIII centers.
Describe the biological relevance of NO.
Identify the biological roles of flavodiiron nitric oxide reductases.
Identify the cofactors in flavodiiron nitric oxide reductase enzymes and describe their roles in converting NO to N2O.
Describe the importance of modeling the FNOR active site and investigating the mechanism of N2O formation through a computational investigation.
Explain the importance of studying model complexes in bioinorganic chemistry and analyze the similarities/differences between a model and active site.
Write a balanced half reaction for the conversion of NO to N2O and analyze a reaction in terms of bonds broken and bonds formed.
Interpret the reaction pathway for the formation of N2O by flavodiiron nitric oxide reductase and identify the reactants, intermediates, transition states, and products.
A successful advanced undergrad student will be able to:
Explain antiferromagnetic coupling.
Apply hard soft acid base theory to examine an intermediate state of the FNOR mechanism and apply the importance of the transition state to product formation of N2O.
Apply molecular orbitals of the NO species and determine donor/acceptor properties with the d-orbitals of the diiron center.
This paper is quite advanced and long, so faculty should direct students to which sections they should read prior to the class discussion. Information about which parts of the paper to read for the discussion are included on the handout. Questions #7 and #8 are more advanced, and may be included/excluded depending on the level of the course.