Bridged Aminotroponiminate Complexes of Lanthanum

The reaction of the new ligand 1,3-di(2-(N-isopropylamino)troponimine)propane, H(2)[(iPr)TP], with KH affords K(2)[(iPr)TP]. The salt of this new ligand is a useful starting material for the preparation of the lanthanum compounds [[(iPr)TP](3)La(2)(THF)](2) and [[(iPr)TP]LaCl(THF)](2), respectively. These metal complexes were characterized by NMR and X-ray crystallography. In contrast to macrocyclic ligands the [(iPr)TP](2)(-) anion shows a higher flexibility upon coordination and features two different coordination modes. Further reaction of [[(iPr)TP]LaCl(THF)](2) with 2 equiv of LiCH(SiMe(3))(2) or KN(SiMe(3))(2) in toluene affords the alkyl or amide derivatives [[(iPr)TP](2)LaE(SiMe(3))(2)] (E = CH, N) in high yield. Crystal data: [[(iPr)TP](3)La(2)(THF)](2), space group P2(1)/c, a = 19.860(2) Å, b = 17.691(3) Å, c = 21.333(3) Å, beta = 102.211(8) degrees, Z = 4, V = 7325.8 Å(3); [[(iPr)TP]LaCl(THF)](2), space group P2(1)/n, a = 12.848(3) Å, b = 32.902(7) Å, c = 16.215(3) Å, beta = 110.38(3) degrees, Z = 4, V = 6425(2) Å(3).