In this talk I will describe methods for altering the chemical composition of arguably the most complex metallocofactors in biology, the nitrogenase catalytic cofactors. A major focus will be an application of this methodology: the incorporation of <sup>57</sup>Fe into specific sites of the Mo nitrogenase catalytic cofactor, FeMo-co. Studies of site-selectively labeled FeMo-co samples yield improved resolution in <sup>57</sup>Fe-based spectroscopies and, more importantly, connect the wealth of chemical-bonding information in the spectroscopic data to the 3-D structure. New insights into the resting state and intermediates in nitrogen fixation will be discussed.

Insights into biological nitrogen fixation from chemically modified nitrogenase cofactors

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.