Synthesis of Ba(II) analogs of Ln(II)-in-(2.2.2-cryptand) and layered hexagonal net Ln(II) complexes, [(THF)Cs(-⁵:⁵-C₅H₄SiMe3)₃Ln^II]_n

The Ba-in-(2.2.2-cryptand) complexes, [Ba(2.2.2-cryptand)(DMF)2][I]2 and [Ba(2.2.2-cryptand)(OTf)2], were synthesized from the reaction of 2.2.2-cryptand with BaI2 and Ba(OTf)(2), respectively, and crystallographically characterized for comparison with lanthanide analogs. The complexes are soluble in THF, just as their Ln = Nd and Sm analogs. The reaction of a mixture of BaI2 and KCp ' (Cp ' = C5H4SiMe3) in THF with excess Cs metal yielded crystals of the layered complex, [(THF)Cs(mu-eta(5):eta(5)-Cp ')(3)Ba(THF)](n), which was crystallographically characterized for comparison with [(THF)Cs(mu-eta(5):eta(5)-Cp ')(3)Yb-II](n). A solvent-free analog of these complexes, [Cs (mu-eta(5):eta(5)-Cp ')(3)Yb-II](n), is also reported such that the three structures demonstrate that the layered structure is stable to variable amounts of THF coordination, which is important in using this network as a thin film precursor.