Ligand-based reduction of nitrate to nitric oxide utilizing a proton-responsive secondary coordination sphere.

Utilizing the proton-responsive pyridinediimine ligand [(2,6-iPrC6H3)(N[double bond, length as m-dash]CMe)(N(iPr)2C2H4)(N[double bond, length as m-dash]CMe)C5H3N] (didpa), the ligand-based reduction of nitrate (NO3-) to nitric oxide (NO) was achieved. The bioinspired [Fe(Hdidpa)(CO)2]+ was shown to react with tetrabutylammonium nitrate to form the dinitrosyl iron complex [Fe(didpa)(NO)2]+. The didpa scaffold was shown to provide two electrons for the net reduction of NO3- to NO in 43% yield.