The first homoleptic bis(trifluoromethanesulfonyl)amide complex of yttrium: [bmim][Y(Tf2N)(4)]

1-Butyl-3-methylimidazolium tetrakis-(bis(trifluoromethanesulfonyl)amide)yttrium(III), [bmim][Y(Tf2N)(4)], was obtained from the ionic liquid 1-butyl-3-methylimidazoliumbis(trifluoromethanesulfonyl)amide, [bmim][Tf2N] and yttrium(111)bis(trifluoromethanesulfonyl)amide, Y(Tf2N)(3). The crystal structure [monoclinic, C2/c (no. 15), a = 2096.(1), b = 1451.5(1), c 1608.55(9) pm, beta = 109.669(6)degrees, V = 4608.1(5)(.)10(6) pm(3), Z = 4, R-1 for 3874 symmetry independent reflections with I-0>2 sigma(I-0): 0.0438] contains Y-III coordinated by four Tf2N-ligands which all adopt a transoid-conformation with respect to their -CF3 groups. The oxygen coordination polyhedron around Y-III can be best described as a trigonal dodecahedron. One 1-butyl-3-methylimidazolium cation compensates for the charge of the complex [Y(Tf2N)(4)](-) anion.