, a = 10.321(2) Angstrom, b = 11.116(2) Angstrom, c = 13.434(3) Angstrom, alpha = 107.57(3)degrees, beta = 111.31(3)degrees, gamma = 90.67(3)degrees, V = 1356.1(5) Angstrom(3), Z = 1, R = 0.0233; 5, monoclinic, P2(1)/n, a = 13.913(13) Angstrom, b = 12.914(9) Angstrom, c = 16.434(14) Angstrom, beta = 105.64(3)degrees, V = 2843(4) Angstrom 3, Z = 2, R = 0.0281. The chloro functions in 1-6 remain reactive, demonstrated by the isolation of the trifluoroacetate derivatives of 1 and 2. Treatment of 1 or 2 with 2 equiv of NaOCOCF3 gives [{{(t-Bu)NSiMe(2)SiMe(2)N(t-Bu)}Ln(mu-OCOCF3)(THF)}(2)] (7, Ln = Nd; 8, Ln Gd). The structure of 8 was determined by a single-crystal X-ray diffraction analysis. Crystal data for 8 : triclinic,
, a = 11.045(2) Angstrom, b = 16.120(3) Angstrom, c = 16.949(3) Angstrom, alpha = 66.17(3)degrees, beta = 85.51(3)degrees, gamma = 78.27(3)degrees, V = 2702.9(9) Angstrom(3), Z = 2, R = 0.0311. The structure of 8 shows the trifluoroacetate group adopting a bridging bidentate mode of coordination.