Mono- and Disamarium Azacryptand Complexes: A Platform for Cooperative Rare-Earth Metal Chemistry

[Image: see text] Mono- (H(3)LSm) and disamarium complexes (LSm(2)) were prepared by reaction of the azacryptand N[(CH(2))(2)NHCH(2)-p-C(6)H(4)CH(2)NH(CH(2))(2)](3)N (H(6)L) with 1 or 2 equiv of Sm[N(SiMe(3))(2)](3), respectively. The disamarium complex features free coordination sites on both metal centers available for bridging ligands shielded by phenylenes from tetrahydrofuran (THF) coordination. The reaction of LSm(2) with KCN and 18-crown-6 yielded the adduct [LSm(2)-μ-η(1):η(1)-CN][K(18-crown-6)(THF)(2)] featuring a bridging cyanide. The complexes were characterized by crystallography, electrochemical analysis, NMR, and optical spectroscopy, and the effective magnetic moments were determined via the Evans method.