Jörn Winterfeld

Organometallic compounds of the lanthanides. CXXIII. Lanthanide bent-sandwich complexes with the bulky tetramethyl- iso -propylcyclopentadienyl ligand—synthesis, structures and catalytic activity for the hydrosilylation of alkenes/alkynes

Abstract The trichlorides of yttrium, samarium and lutetium react with two equivalents of Na[C5Me4u2008iPr] in THF to form [(η5-C5Me4u2008iPr)2LnCl(THF)] (Ln=Y (1), Sm (2), Lu (3)). Metathesis of 1–3 with LiCH3 in diethyl ether and LiCH(SiMe3)2 in toluene gives [(η5-C5Me4u2008iPr)2LnCH3(THF)] (Ln=Y (4), Lu (5)) and [(η5-C5Me4u2008iPr)2Ln{CH(SiMe3)2}] (Ln=Y (6), Sm (7)), respectively. The 1:2 reaction of LnI2(THF)x (Ln=Sm, Yb) with Na[C5Me4u2008iPr] in THF results in the formation of the divalent metallocenes [(η5-C5Me4u2008iPr)2Ln(THF)] (Ln=Sm (8), Yb (9)). The new compounds with the bulky tetramethyl-iso-propylcyclopentadienyl ligands were characterized by C, H analysis, mass spectrometry and NMR spectroscopy. Additionally, single crystal X-ray structure determination of the lutetium complexes 3 and 5 was performed. It has been shown that the alkyl complexes 4–7 are effective precatalysts for the hydrosilylation of alkenes and alkynes. The results of the described investigations are discussed.

Metallorganische verbindungen der lanthanoide CIX organolanthanoidfluoride: Synthese und strukturaufklärung von trimerem Bis(tert.-butylcyclopentadienyl)samarium(III)-fluorid

Abstract The organolanthanide fluoride [( η 5 -C 5 H 4 1 Bu) 2 Sm( μ -F))] 3 ( 1 ) was generated by oxidation of [( η 5 -C 5 H 4 1 Bu) 2 Sm(THF) 2 ] with Me 3 SnF. The X-ray structural analysis of 1 showed the trimeric compound to be monoclinic space group C 2/ c , Z = 4, with a = 18444.6(6), b = 1537.5(3), c = 1871.2(9)pm, β = 104.55(4)° and D calc = 1.597 g cm 3 . The structure was solved from 3942 observed reflections with F o > 4 σ ( F o ) and refined to a final R = 0.0735.

Metallorganische verbindungen der lanthanoide: LXXVI. cyclooctatetraenyl(tetramethylcyclopentadienyl)-komplexe der lanthanoide☆

Abstract The complexes [(C8H8)Ln(μ-Cl)(THF)n]2 (Ln = Y, La, Pr, Sm, Gd, Dy, Er, Lu) react with Na(C5Me4H) in THF to yield complexes (C8H8)Ln(C5Me4H)(THF)x (Ln = Y, La, Pr, Sm, Gd, Dy, Er, Lu). Crystals of (C8H8)La(C5Me4H)(THF) 2 (2) are monoclinic, space group P21/n with a = 850.80(15), b = 1183.5(2), c = 2290.1(5) pm, β = 96.707(16)°, V = 2273.8(8) × 10−30 m3 and Z = 4. Least-squares refinement on the basis of 3070 reflections (Fo > 6σ(Fo)) led to a final R of 0.0305. Compound (C8H8)Lu(C5Me4H) (8) crystallizes monoclinic, space group P21/m with a = 927.6 (2), b = 1431.3(4), c = 1114.4(2) pm, β = 90.41(1)°, V = 1479.5(5) × 10−30 m3 and Z = 4. Least-squares refinement on the basis of 2329 reflections (Fo> 4σ(Fo)) led to a final R of 0.0276.

Organometallic compounds of the lanthanides. CIII Mixed sandwich complexes of the 4f elements: synthesis and crystal structure of (ν8-cyclooctatetraenyl)(ν5-2,5-di-tert.-butylpyrrolyl) samarium, -thulium, and -lutetium☆

[(ν8-C8H8)Ln(μ-Cl)(THF)]2 (Ln = Sm, Tm, Lu) reacts with Na[pyr∗] (pyr∗ = NC4H2tBu2-2,5) to form [(ν8-C8H8)Ln(ν5-pyr∗)(THF)x] (Ln = Sm 1, x = 1; Ln = Tm 2, Lu 3, x = 0). The novel sandwich compounds have been characterized by C,H,N analysis, mass spectrometry and NMR spectroscopy. Additionally, an X-ray structural analysis of 1 was performed. The crystals of 1 are monoclinic, space group P21/c with a = 11.131(2) A, b = 20.023(3) A, c = 20.118(5) A, β = 91.16(2)°, V = 4482.8(14) A3and Z = 4. The final refinement resulted in R1 = 3.09% (I>2σ(I)).

Metallorganische Verbindungen der Lanthanoide XCVIII Synthese und Strukturaufklärung von Dichloro(η5-2,5-di-tert.-butylpyrrolyl) bis(tetrahydrofuran) ytterbium(III)

Zusammenfassung The reaction between YbCl 3 (THF) 3 and Na[pyr ∗ ] (pyr ∗ = NC 4 H 2 t Bu 2 -2,5) yields the monopyrrolyl complex, [(pyr ∗ )YbCl 2 (THF) 2 ] ( 1 ). The X-ray structure of compound 1 confirms the π -coordination between the metal and the azacyclopentadienyl ligand.

Metallorganische verbindungen der lanthanoide: LXXXV. Synthese und strukturaufklärung neuer cyclooctatetraenyl-cyclopentadienyl-sandwich-komplexe der seltenen erden

Abstract The mixed sandwich complexes [(C 8 H 8 )Ln(C 5 Me 4 Et)(THF) x ] (Ln = Y 1 , La 2 , Nd 3 , Sm 4 , Gd 5 , Tm 6 , Lu 7 ), [(C 8 H 8 )Ln{C 5 H 2 (SiMe 3 ) 3 }(THF) x (Ln = Pr 8 , Dy 9 ) and [(C 8 H 8 )Pr(C 5 Ph 5 )] ( 10 ), have been prepared by the metathetic reaction of [(C 8 H 8 )Ln(μ-Cl)-(THF) n ] 2 with NaC 5 Me 4 Et, LiC 5 H 2 (SiMe 3 ) 3 and NaC 5 Ph 5 in THF. The 1:2 reaction of 7 with acetylacetone results in displacement of the (C 8 H 8 )-ligand to generate the new complex [(C 5 Me 4 Et)Ln(acac) 2 ] (acac = [CH 3 C(O)CHC(O)CH 3 ] − ) ( 11 ). The molecular structures of 7 (monoclinic space group P 2 1 / c with a = 990.4(5) pm, b = 1228.2(5) pm, c = 2757.5(16) pm, β = 93.92(4)°, V = 3346(3)·10 −30 m 3 and Z = 8) and 11 (triclinic space group P 1 with a = 957.3(3) pm, b = 1064.5(2) pm, c = 1068.3(2) pm, α = 94.19(12)°, β = 96.37(17)°, γ = 96.71(16)°, V = 1070.3(4)·10 −30 m 3 and Z = 2) have been determined by X-ray diffraction.