The Ln2+ complexes [K(2.2.2-cryptand)][Cp′3Ln] (Ln = La, Ce, Pr, Nd, Sm, Eu, Dy, Tm, Yb; Cp′ = C5H4SiMe3) were reacted with 1,3,5,7-cyclooctatetraene, C8H8, to determine if the reactivity of the complexes of 4fn+1 ions differed from that of 4fn5d1 ions. Crystallographically characterizable (C8H8)2- complexes were obtained only for the larger metals in the lanthanide series, and two types of products were obtained: [K(2.2.2-cryptand)][Cp′2Ln(C8H8)] (Ln = La, Ce) and [K(2.2.2-cryptand)][Ln(C8H8)2] (Ln = Ce, Pr, Nd, Sm). The expected co-products of the two-electron reduction of C8H8 by 2 equiv of [K(2.2.2-cryptand)][Cp′3Ln], namely, the tetrakis(cyclopentadienyl) complexes, [K(2.2.2-cryptand)][Cp′4Ln], were crystallographically characterized for six metals (Ln = Ce, Pr, Nd, Sm, Dy, Tm).
Bibliographical noteFunding Information:
This research was supported by the National Science Foundation (NSF) under CHE-1565776 to W.J.E. We thank Dr. Jordan F. Corbey and Dr. Jason R. Jones for crystallographic assistance. We also thank NSF for providing graduate fellowship support for C.T.P. (DGE-1321846).