Iridium Hydride Mediated Stannane–Fluorine and −Chlorine σ‑Bond Activation: Reversible Switching between X‑Type Stannyl and Z‑Type Stannane Ligands

Iridium­(I) carbonyl hydride Ir­(H)­(CO)­(PPh3)3 (1) cleaves the Sn–F and Sn–Cl bonds of four-coordinate stannanes {o-(Ph2P)­C6H4}3Sn­(X) (X = F (2a) and Cl­(2b)) to afford the stannyl complex [{o-(Ph2P)­C6H4}3Sn]­Ir­(CO) (3) and HX (X = F and Cl) thanks to phosphine chelation. A plausible intermediate [{o-(Ph2P)­C6H4}3(Cl)­Sn]­Ir­(H)­(CO) (6) featuring Z-type Ir → R3SnCl interaction was synthesized by the reaction of 3 with HCl. Compound 6 readily regenerated 3 upon treatment with Brønsted bases, enabling reversible switching between X-type stannyl and Z-type stannane ligands. Density functional theory calculations suggest plausible pathways for Sn–F and Sn–Cl bond cleavage reactions and support the idea that the species bearing a Z-type Ir → R3SnX interactions (X = F and Cl) are intermediates for Sn–X bond cleavage.