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 [C...