The coupling of two nitric oxide (NO) molecules in heme active sites is an important contributor to the conversion of NO to nitrous oxide (N2O) by heme-containing enzymes. Several formulations for the presumed heme-Fe{N2O2}(n+) intermediates have been proposed previously, however, no crystal structures of heme-Fe{N2O2}(n+), systems have been reported to date. We report the first isolation and characterization of a stable bimetallic hyponitrite iron porphyrin, [(OEP)Fe](2)(mu-N2O2), prepared from the reaction of [(OEP)Fe](2)(mu-O) with hyponitrous acid. Density functional theoretical calculations were performed on the model compound [(porphine)Fe](2)(mu-N2O2) to characterize its electronic structure and properties.