Synthesis and Structure of New Soluble Organosamarium(II) Reagents: (indenyl)2Sm(THF) and (fluorenyl)2Sm(THF)2

Evans, William J.; Gummersheimer, Tammy S.; Boyle, Timothy J.; Ziller, Joseph W.

doi:10.1021/om00016a034

Cited by 49 publications

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“…samarium center is bound to the indenyl ring in an g 5 -manner; the samarium-carbon bond lengths range from 2.809(4) to 2.911(5) Å with an average 2.851 Å as compared to a range of 2.81(1)-2.91(1) Å and an average of 2.86(3) Å in (C 5 Me 5 ) 2 Sm II (THF) 2 [9]. The SmCent distance of 2.580 Å is also comparable to a related value of 2.631 Å reported for (C 13 H 9 ) 2 Sm II (THF) 2 [7], 2.583 Å for [C 5 Me 4 SiMe 2 (iPr-tacn)]Sm II I [10] and 2.534 Å for [(C 5 Me 5 )Sm II (l-I)(THF) 2 ] 2 [9]. The samarium-nitrogen bond length is 2.691(5) Å , which is typical for distances between samarium and bulky amine donors, and is similar to the bond lengths observed in (1,4,7-triazacyclononoane-1,4,7-triltris(2-(ethylimino)-propionato))samarium (2.669(4)-2.690(4) Å ) [11].…”

Section: Dihedral Anglessupporting

confidence: 71%

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Organolanthanides with 3-(2-pyridylmethyl) indenyl ligands: synthesis, crystal structures and catalytic activities of divalent complexes for ε-caprolactone polymerization

Cheng

Cui

Chen

et al. 2004

Journal of Organometallic Chemistry

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Section: Dihedral Anglessupporting

confidence: 71%

“…2) in the same position in the unit cell, and their space occupation ratio is 50:50. While most of the coordination number of divalent lanthanocenes is 8, only several complexes are 9-coordinate, such as (C 9 H 7 ) 2 Sm II (THF) 3 [7] and (MeOCH 2 CH 2 C 5 H 2 ) 2 -Yb II (THF) [8]. As shown in Fig.…”

Section: Molecular Structures Of 2 Andmentioning

confidence: 99%

Organolanthanides with 3-(2-pyridylmethyl) indenyl ligands: synthesis, crystal structures and catalytic activities of divalent complexes for ε-caprolactone polymerization

Cheng

Cui

Chen

et al. 2004

Journal of Organometallic Chemistry

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“…Reaction [6] can be carried out in THF whereas reaction [5] cannot, because the (C,Me,),Sm ring-opens THF to make (CSMes),Sm[ O(CH2)4CsMes](THF) . 37 When reactions [2], [4], [6] and [8] are compared, reaction [2] becomes the exception in that one of the two major products is a bis(indeny1)-samarium(II1) compound and not a mono(indenyl)samarium(III) complex. Hence, in CSMe5/Sm chemistry, bis(cyclopentadieny1) products are predominant and mono(ring) compounds are formed only rarely.…”

Section: Discussionmentioning

confidence: 99%

The reactivity of Samarium(II) in a Bis(indenyl) coordination environment

Evans

Gummersheimer

1995

Applied Organom Chemis

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The reactivity of the organosamarium(II) indenyl complex (C9H7)2Sm(THF)x, 1, has been compared with that of (C5Me5)2Sm(THF)2, 2, and (C5Me5)2Sm, 3, by examination of characteristic organosamarium(II) reactions which form trivalent oxide, iodide, cyclo‐octatetraenyl and azobenzene complexes. Complex 1 reacts with excess N2O to form [(C9H7)2Sm(THF)]2(μ‐O), 4, and (C9H7)3Sm(THF), 5, as the major products. Two equivalents of 1 react with one equivalent of 1,2‐di‐iodoethane in THF to give (C9H7)SmI2(THF)2, 6, as well as 5. Complex 1 reacts with 1,3,5,7‐cyclo‐octatetraene in a 2:1 ratio in THF to form 5 and (C9H7)Sm(C8H8)(THF)x, 7, which has been fully characterized as the 2,2′‐bipyridine adduct (C9H7)Sm(C8H8)(C10H8N2), 7a. The reaction of 1 with azobenzene in a 2:1 ratio forms [(C9H7)Sm(N2Ph2)(THF)]x, 8, and 5. Complexes 4–6 and 7a have been definitively identified by X‐ray crystallography. Complex 4 crystallizes from THF in space group P1― [C 11; No. 2] with unit cell parameters at 163 K of a = 8.072(2) Å, b = 9.502(2) Å, c = 12.250(3) Å, α = 101.42(2)°, β = 90.71(2)°, γ = 102.50(2)°, V = 897.7(4) Å3 and Z = 1 for Dcalcd = 1.704 Mgm−3. Least‐squares refinement of the model based on 3924 reflections (|F0|)>3.0 σ (|F0|)) converged to a final RF=2.4%. The geometry around each Sm atom is a distorted tetrahedron and the Sm–O–Sm angle is 180°. Complex 5 crystallizes from THF/hexanes at −35°C in space group P63 [C 66; No. 173] with unit cell parameters at 163 K of a = 11.7370(14) Å, c = 10.1994(12) Å, V = 1216.8(3) Å3 and Z = 2 for Dcalcd = 1.550 Mg m−3. Least‐squares refinement of the model based on 976 reflections (|F0|> 3.0σ (|F0|) converged to a final RF = 2.3%. The three ring centroids and the THF oxygen atom define a distorted tetrahedron around samarium with a (ring centroid)–Sm–(ring centroid) angle of 116.0°. Complex 6 crystallizes from THF/hexanes as the trisolvate (C9H7)SmI2(THF)3, 6a, in space group P21/n [C 2h5; No. 14] with unit cell parameters at 163 K of a = 8.3969(12) Å, b = 17.165(5) Å, c = 33.592(7) Å, β = 96.468(15)°, V = 4811(2) Å3 and Z = 8 for Dcalcd = 2.031 Mg m−3. Least‐squares refinement of the model based on 5664 reflections (|F0|> 2.0 σ (|F0|)) converged to a final RF = 3.3%. The six ligands around Sm in 6a describe a distorted octahedron. The iodide ligands are trans to each other with a 153.8(1)° I–Sm–I angle. Adduct 7a crystallizes from hot THF/toluene in space group P1 [C 11; No. 2] with a unit cell parameters at 163 K of a = 7.886(7) Å, b = 16.72(2) Å, c = 17.48(2) Å, α = 62.96(7)°, β = 85.17(7)°, γ = 85.23(9)°, V = 2042(3) Å3 and Z = 4. The cyclooctateraenyl and indenyl ligands generate a bent metallocene structure for 7a which contains a chelating bipyridyl group in the plane bisecting the two rings.

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“…The thermal ellipsoids are drawn at the 30% probability level. ligand (a), g 3 bonded (b), e.g., in (g 5 :g 3 -CpSiMe 2 Flu)-YCl 2 Li(OEt 2 ) 2 [25] and (g 5 :g 3 -Flu) 2 Sm(THF) 2 [26], and symmetrically g 1 bonded (c) as in Me 2 Si(g 1 -Flu 0 )(g 1 -N-tBu)ZrCl 2 OEt 2 (Flu 0 = C 29 H 36 ) [27].…”

Section: Synthesis and Crystal Structures Of Complexesmentioning

confidence: 99%

Stereospecific polymerization of propylene with group 4 ansa-fluorenylamidodimethyl complexes

Nishii

Hagihara

Ikeda

et al. 2006

Journal of Organometallic Chemistry

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Group 4 [g 1 :g 3 -tert-butyl(dimethylfluorenylsilyl)amido]dimethyl complexes [t-BuNSiMe 2 Flu]MMe 2 (M = Ti, 1; Zr, 2; Hf, 3) were synthesized in a one-pot synthesis starting from the ligand, MeLi and MCl 4 (M = Ti, Zr, Hf), respectively. The structures of these complexes were determined by X-ray crystallography and the results obtained revealed that the fluorenyl ligand coordinates to center metal in a g 3 -manner irrespective of center metal employed. Propylene polymerization was conducted at 0 or 20°C in toluene by 1-3 combined with dried methylaluminoxane (MAO), which was prepared from the toluene solutions of MAO by removing free trialkylaluminiums, and HNMe 2 PhB(C 6 F 5 ) 4 in the presence of triisobutylaluminium. The 1-dried MAO system gave the polymer with syndiotactic triad (rr) of 63% at 0°C, whereas 2 and 3 did not give any polymer in the same conditions. The 2-dried MAO system gave the polymer with the highest syndiotacticity (rr = 97%) at 20°C, although the activity was low. The 3-dried MAO system did not give any polymer even at 20°C. When HNMe 2 PhB(C 6 F 5 ) 4 was used in place of dried MAO at 20°C, 1 gave almost atactic polymer, while 2 and 3 gave highly syndiotactic one (rr > 90%). These results indicate that the catalytic performance strongly depended on the center metal of the ansafluorenylamidodimethyl complexes as well as cocatalysts employed.

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Synthesis and Structure of New Soluble Organosamarium(II) Reagents: (indenyl)2Sm(THF) and (fluorenyl)2Sm(THF)2

Cited by 49 publications

References 0 publications

Organolanthanides with 3-(2-pyridylmethyl) indenyl ligands: synthesis, crystal structures and catalytic activities of divalent complexes for ε-caprolactone polymerization

Organolanthanides with 3-(2-pyridylmethyl) indenyl ligands: synthesis, crystal structures and catalytic activities of divalent complexes for ε-caprolactone polymerization

The reactivity of Samarium(II) in a Bis(indenyl) coordination environment

Stereospecific polymerization of propylene with group 4 ansa-fluorenylamidodimethyl complexes

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