REACTIVITY OF (C5ME5)2SM AND RELATED SPECIES WITH ALKENES - SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF A SERIES OF ORGANOSAMARIUM ALLYL COMPLEXES

The reactivity of (C5Me5)2Sm (1) with alkenes has been examined and compared with that of (C5Me5)2Sm(THF)2 (2) and [(C5Me5)2Sm(M-H)]2 (3). I reacted rapidly with a variety of alkenes in hexane or toluene to form allyl complexes and alkane byproducts. Reactions with propene, butene, and allylbenzene formed (C5Me5)2Sm(η3-CH2CHCH2) (4), (C5Me5)2Sm(η3-CH2CHCHMe) (5), and (C5Me5)2Sm(η3-CH2CHCHPh) (6), respectively, in 85-95% yield. Complexes 4-6 were also prepared in similar yield from 3 and the appropriate alkene in hexane. The corresponding alkane was again the byproduct. Reactions of 3 with these alkenes in toluene formed (C5Me5)Sm(CH2C6H5) exclusively. 1 reacted with 1,3-butadiene and 1,5-hexadiene to form the bis-allyl complexes [(C5Me5)2Sm(μ-η3-CH2CHCHCH2-)]2 (7) and [(C5Me5)2Sm(η-μ3CH2CHCH-)]2 (8). In contrast, 3 reacted with butadiene to form 5. 2 reacts like 1 with allylbenzene and 1,3-butadiene to form 6 and 7. 2 is not very reactive with propene and forms complex mixtures of products with butene and 1,5-hexadiene. Complex 4 crystallizes from hexane in the tetragonal space group 14 (no. 82; S42) with unit cell parameters a = 23.1043 (36) Å, c = 8.4586 (12) Å, V = 4515 (1) Å3, and Z = 8 for Dcalcd = 1.36 g cm-3. Least-squares refinement of the model based on 1894 observed reflections converged to RF = 4.7%. Complex 5 crystallizes from hexane in the monoclinic space group P21/n with unit cell parameters a = 15.9367 (41) Å, 6= 17.7780 (32) Å, c= 16.7024 (48) Å, β = 101.381 (20)°, F= 4639 (2) Å3, and Z = 8 for Dcalcd = 1.36 g cm-3. Least-squares refinement of the two crystallographically independent molecules based on 4688 observed reflections converged to RF = 7.5%. Complex 6 was crystallized from hexane at -34 °C as the 1,3-dihydroisobenzofuran adduct (C5Me5)2Sm(η3-CH2CHCHPh)(OC8H8), 6′, in the monoclinic space group P21/c with unit cell parameters a = 10.3851 (16) Å, b = 17.357(3) Å, c = 17.703 (2) Å, β = 95.785 (12)°, and V= 3174.9 (8) Å3 with Z = 4 for Dca1cd = 1.38 g cm-3. Least-squares refinement of the model based on 6964 observed reflections converged to RF = 3.1%. Complex 7 crystallizes from toluene/hexane in the orthorhombic space group Pbca (no. 61; D>2h15) with unit ce11 parameters a = 16.5911 (26) Å, b = 29.8565 (49) Å, c = 18.0130 (25) Å, V = 8923 (2) Å3, and Z = 8 for Daiei = 1.41 g cm-3. Least-squares refinement of the model based on 4134 observed reflections converged to RF = 6.9%. Complex 8 crystallizes from hexane in the monoclinic space group P2fc with unit cell parameters a = 13.953 (12) Å, b = 8.445 (4) Å, c = 18.635 (10) Å, β = 102.85 (5)° and V = 2143 (2) Å3 with Z = 2 for ZDcalcd = 1.43 g cm-3. © 1990, American Chemical Society. All rights reserved.