why can only $\mathrm{Fe} 2+$ bind oxygen in heme and not $\mathrm{Fe} 3+$

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∻Answer∻ ⚹ Only $Fe^{2+}$ can bind oxygen in heme, not $Fe^{3+}$ ⚹ ∻Solution∻ ‖ a ⋮ Iron oxidation states: Iron can exist in multiple oxidation states, but in the context of heme, the relevant states are $Fe^{2+}$ (ferrous) and $Fe^{3+}$ (ferric). ‖‖ b ⋮ Oxygen binding: The heme group in hemoglobin binds oxygen through its iron atom. Only $Fe^{2+}$ can reversibly bind oxygen. ‖‖ c ⋮ Electron configuration: $Fe^{2+}$ has the appropriate electron configuration to form a stable complex with oxygen, whereas $Fe^{3+}$ does not. ‖ ∻Key Concept∻ ⚹ Iron oxidation states in heme ⚹ ∻Explanation∻ ⚹ $Fe^{2+}$ can bind oxygen due to its electron configuration, while $Fe^{3+}$ cannot form a stable complex with oxygen. ⚹◊What is the difference in the electronic configuration between $Fe^{2+}$ and $Fe^{3+}$ that allows only $Fe^{2+}$ to bind oxygen in heme?⍭ Generate me a similar question◊

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