Half‐sandwich Complexes [Cp'4Ln4I8]4 (Ln = Ce, Pr) Emergence of Donor‐free Organolanthanide Nanowheels

Slow diffusion of Me3SiI into an n-hexane solution lanthanide half-sandwich complexes [Cp′Ln(AlMe4)2] (Ln=Ce, Pr; Cp′=C5H4SiMe3) gives access to the hexadecalanthanide ring-cluster hybrids [Cp′4Ln4I8]4, along with cyclopentadienyl-bridged {Ce8} cluster [Cp′4Ce4I7(μ2-Cp)]2. On contrary, direct addition halogenating reagent complex [Cp′Ce(AlMe4)2] in affords spherical dodecanuclear [Cp′CeI2]12 [Cp′4Ln4I8]4. The isostructural bromide and chloride clusters [Cp′LnX2]12 (X=Cl, Br) were isolated via same synthesis protocol, using mild halogenido transfer reagents Me3GeX Br). reaction [Cp′Ce(AlMe4)2]/Me3GeCl yielded decanuclear heteroaluminato derivative [Cp′5Ce5Cl9(AlCl2Me2)]2 as a coproduct. Attempts isolate any intermediate species by performing at low temperature resulted incomplete AlMe4/iodido exchange, affording hexanuclear homoaluminate [Cp′6Pr6I8(AlMe4)4]. All cerium show bright photoluminescence under UV light. luminescence properties [Cp′CeX2]12 Br, I) closer investigated.