Lanthanide Phosphido Complexes: A Comparison of the Divalent Homoleptic Species Ln[(μ-PtBu2)2Li(thf)]2 (Ln = Yb, Eu, Sm) Including the Structural Characterization and a Europium-151 Mössbauer Spectrum of Eu[(μ-PtBu2)2Li(thf)]21
journal contributionposted on 16.07.1997, 00:00 by Gerd W. Rabe, Glenn P. A. Yap, Arnold L. Rheingold
A comparison of the three isostructural homoleptic lanthanide phosphide species Ln[(μ-PtBu2)2Li(thf)]2 [Ln = Yb (1), Eu (2), Sm (3)] is reported. Eu(OSO2CF3)3 reacts with 5 equiv of LiPtBu2 in tetrahydrofuran to give the europium complex Eu[(μ-PtBu2)2Li(thf)]2 (2) in 50% yield plus 0.5 equiv of tBu2P−PtBu2. 2 crystallizes in space group P21/c. Crystal data for 2 at 248 K: a = 21.740(3) Å, b = 12.345(1) Å, c = 20.633(2) Å, β = 109.13(1)°; V = 5231.5(10) Å3; Z = 4; Dcalcd = 1.131 g cm-3; RF = 3.29%. The molecular structure shows the four-coordinate europium atom in a distorted tetrahedral environment. A main feature of the crystal structure of 2 is the shortest Eu−P distance [3.034(1) Å] of divalent europium reported so far. A 151Eu Mössbauer spectrum at 4.2 K is reported exhibiting an isomer shift of −11.7 mm/s.