CrCl3 and FeCl3 are stable, useful compounds. So, where is MnCl3? Seeded by this curiosity, my research focuses on a class of manganese compounds that have historically been inaccessible due to their instability: Mn(III) tri-halide and tri-pseudohalide complexes. We found the instability arises from an unusual electronic structure and their extremely high one-electron reduction potentials. Nature leverages these properties in processes such as photosynthesis, microbial metabolism, and the oxidative degradation of organic matter. We have developed strategies to stabilize these complexes while preserving their high-potential reactivity, establishing a new chemical platform to previously inaccessible bond-forming reactions and mechanistic insight into manganese redox cycling across biological and environmental systems. We also demonstrate their utility in organic synthesis through stereoselective alkene dihalogenation and benzylic C–H functionalization.