Using mass spectrometric identification, for the first time the gaseous iron salts are found, in which FeO acts as anion-forming oxide - SrFeO₂ and BAFeO₂. Standard enthalpies of formation and atomization are determined for these molecules, as well as other thermodynamic characteristics. For CaFeO₂, considered as structural analogue of the studied molecules, the ab initio calculations of geometric and electron structure and also vibration spectra were conducted.