Sn,P-Peri-Substituted Naphthalene as a Ligand for Transition Metals

Peri-substituted naphthalene 1-PPh2-8-SnL-C10H6 (1) [L = 2,6-(Me2NCH2)2C6H3] was used as a ligand for the complexation of transition metals (TMs). The presence of two donor atoms provided rigid κ2P,Sn-coordinated complexes of TM. Correspondingly, reactions of 1 with binuclear Mn2(CO)10 and Co2(CO)8 yielded ionic complexes [(κ2-1)Mn(CO)4]+ [Mn(CO)5]− (2) and [(κ2-1)Co(CO)3]+ [Co(CO)4]− (3), first examples of Sn-coordinated Mn(CO)4+ and Co(CO)3+ cations. The reactivity of 1 toward TM–Cl complexes is quite different. During these reactions, transmetallation with subsequent elimination of L(Cl)Sn was observed. However, L(Cl)Sn remained in the coordination sphere of the TM, yielding P-coordinated heterobimetallic TM complexes 1-PPh2-8-[Rh(COD){Sn(Cl)L}]C10H6 (7), 1-PPh2-8-[Ir(COD){Sn(Cl)L}]C10H6 (8), and 1-PPh2-8-[Pd(Cl){Sn(Cl)L}]-C10H6 (9) with additional Sn→TM intermolecular coordination. These transmetallations may be kinetically driven, as suggested by density functional theory calculations and isolation of the κ2P,Sn-coordinated complex of PtCl2, [(κ2-1)PtCl2] (10). Thus, the reactivity of 1 clearly deviates from the P,Sn-based ligands studied so far.