Reactivity of Cr+(S-6,D-4), Mn+(S-7,S-5), and Fe+(D-6,F-4): Reaction of Cr+, Mn+, and Fe+ with water

The study of the reaction of water with the first-row transition-metal ions is continued in this work. Here we report the study of the reaction of wat er with the middle (Cr+, Mn+, and Fe+) first-row transition-metal cations i n both high- and low-spin states. In agreement with experimental observatio ns, the oxides are predicted to be more reactive than the metal ions, and n o exothermic products are observed. Formation of endothermic products is ex amined. An in-depth analysis of the reaction paths leading to the observed products is given, including various minima, and several important transiti on states. All results have been compared with existing experimental and th eoretical data, and our earlier works covering the (Sc+, Ti+, V+) + H2O rea ctions to observe existent trends for the early first-row transition-metal ions. The MO+ + H-2 energy relative to M+ + H2O increases through the serie s from left to right. Additionally, the Fe+ case is seen to be significantl y different from the entire Sc+-Mn+ series because both its low- and high-s pin cases involve paired electrons, and Mn+ shows some differences because of the complete half-filling of its valence shell in the high-spin case.