Heterobimetallic (imido)antimony/lithium cages containing [Sb(NR)3]3-trianions

The reactions of [Sb(NMe2)(3)] with the primary (amido)lithiums [PhCH2CH2N(H)Li](n), [CyN(H)Li](n) (Cy = C6H11), [2,4-dmpN(H)Li](n) [2,4-dmp = 2,4-(MeO)(2)C6H3], and [(BuN)-Bu-t(H)HLi](n) give the heterobimetallic cage complexes [{Sb(NCH2CH2Ph)(3)}(2)Li-6 . 2THF](1), [{Sb(NCy)(3)}(2)Li-6 . 2HNMe(2)]. 2C(6)H(5)CH(3) (2), [Sb{N(2,4-dmp)}(3)](2)Li-6 . 2THF . 2C(6)H(5)-CH3 (3), and [{Sb(NBut)(3)}(2)Li-6] (4), respectively. The low-temperature X-ray structures of 1-4 show that they are composed of 14-membered polyhedral cages constructed from the association of two [Sb(NR)(3)](3-) trianions with six Li+ cations. Crystal data; 2, triclinic, <P(1)over bar>, a = 12.775(6) Angstrom, b = 13.191(9) Angstrom, c = 11.015(5) Angstrom, alpha = 111.55(4)degrees, beta = 95.39(4)degrees, gamma = 115.26(4)degrees; 3, triclinic <P(1)over bar>, a = 10.435(4) Angstrom, b = 12.654(5) Angstrom, c = 14.278(6) Angstrom, alpha = 75.31(4)degrees, beta = 79.33(4)degrees, gamma = 84.33(4)degrees; 4, monoclinic P2(1)/c, a = 9.994(1) Angstrom, b = 17.421(2) Angstrom, c = 10.680(2) Angstrom, beta = 111.33(1)degrees (the structure of 1 being reported previously). Lewis base solvation of the N6Li6 substructures of 1-3 results in distortion and deformation of the Li frameworks. The structural variations in the cores of 1-4 indicate that the bonding in these species is dominated by the valence and bonding demands of the p block metal centers.