| Popis: |
Redox transmetallation ofTl(C5H4PPh2)with an excess of Sm in refluxing thf (thf = tetrahydrofuran) or Eu indme (dme = 1,2-dimethoxyethane) at room temperature gave thelanthanoid(II) compounds[Sm(C5H4PPh2)2](1) and[Eu(C5H4PPh2)2(dme)](2). Crystallization of (1) or[Yb(C5H4PPh2)2(dme)]with OPPh3 in dme yielded[Sm(C5H4PPh2)2(OPPh3)2](3) and[Yb(C5H4PPh2)2(OPPh3)2](4). Room-temperature transmetallation ofTl(C5H4PPh2)with Nd gave the lanthanoid(III) compound[Nd(C5H4PPh2)3(thf)](5), but analogous reactions with La, Pr, Er, Gd and Y in refluxing thfgenerally gave intractable oils, although in one instance impure[La(C5H4PPh2)3(thf)]·(thf)0 · 5,namely(6)·(thf)0 · 5, wasisolated. This complex was also obtained at room temperature by usingLaI3-activated La metal. Oxidation of (1) with 1 equiv.ofTl(C5H4PPh2)in toluene yielded solvent-freeSm(C5H4PPh2)3(7). Addition of OPPh3 to these systems allowed theisolation of[Ln(C5H4PPh2)3(OPPh3)]·(thf)x(x = 0-1 · 5; Ln = La (8), Pr (9),Nd (10), Sm (11), Er (12), Y (13)). Single-crystal X-ray structuredetermination of(10)·(thf)1 · 5,(11)·(thf)1 · 5 and(12)·(thf)1 · 5revealed formally 10-coordinate complexes with an O-bondedOPPh3, threeη5-C5H4PPh2ligands and lattice thf. The centroids of the C5 ringsand the oxygen atom surround the central metal in a distorted tetrahedralarray. |
