Nonclassical Organolanthanoid Metal Chemistry:  [K([18]-crown-6)(η²-PhMe)₂]X (X = [(LnCp^t₃)₂(μ-H)], [(LnCp‘ ‘₂)₂(μ-η⁶:η⁶-PhMe)]) from [LnCp^x₃], K, and [18]-crown-6 in Toluene (Ln = La, Ce; Cp^t = η⁵-C₅H₄SiMe₂Bu^t; Cp‘ ‘ = η⁵-C₅H₃(SiMe₃)₂-1,3)

Treatment of [LnCp^t₃] or [LnCp‘ ‘₃] with potassium and [18]-crown-6 in toluene at ambient temperature yielded two quite different crystalline potassium salts:  [K([18]-crown-6)(η²-PhMe)₂]X (X = [(LnCp^t₃)₂(μ-H)], [(LnCp‘ ‘₂)₂(μ-η⁶:η⁶-PhMe)]; Ln = La, Ce; Cp^t = η⁵-C₅H₄SiMe₂Bu^t; Cp‘ ‘ = η⁵-C₅H₃(SiMe₃)₂-1,3).