Reactivity of (C5Me5)2Sm with cyclopentadiene and cyclopentadienide: isolation of the mixed-valence complex (C5Me5)2Sm(III)(.mu.-C5H5)Sm(II)(C5Me5)2

Abstract

272ChemInform Abstract The title compound (I) react with excess of cyclopentadiene (II) to form the η5-cyclopentadienyl-Sm(III) derivative (III). This is also obtained from the THF diadduct of (I) in similar way (yield 98%). With a deficiency of (II), (I) forms the mixed-valence complex (IV) which is also produced from (III) and (I) by 1:1 molar reaction. The structures of (III) (space group P21/n, Z=4) and (IV) (P1, Z=2) are confirmed by X-ray analysis. In (IV), the bis(pentamethylcyclopentadienyl)-Sm(II) unit coordinates to two C atoms of the cyclopentadienyl ring in the trivalent (C5Me5)2Sm(C5H5) part of the molecule.

Phenylacetylene and Carbon Dioxide Activation by an Organometallic Samarium Complex

“…In the Cp*2Sm(C≡C-Ph)(thf) complex, the Cp*-Sm-Cp* angle is at the opposite end of the range with 138°. The Sm-O distance is 2.504(2) Å close to Evans observation for Cp*2Sm-O (2.47(2) Å) and similar to what has already been observed for this type of complexes [22,23]. The Sm-C≡C-Ph distance is a little shorter than that reported in Evans complex (2.450(3) Å in 1, vs. 2.49(2) Å in Cp*2Sm(C≡C-Ph)(thf) complex).…”

Displacement, reduction, and ligand redistribution reactivity of the cationic mono-C5Me5 Ln2+ complexes (C5Me5)Ln(BPh4) (Ln=Sm, Yb)

“…The 13 C NMR spectrum of 5 is consistent with Sm 3+ [24], suggesting that the bathocuproine has been reduced to a radical anion. Consistent with this, a signal was observed by EPR spectroscopy with a g-value of 1.96.…”

“…The structural parameters and selected bond distances and angles are given in Table 3. The symmetry equivalent, doubly-bridging chloride ligands, Cl (2) Sm] 4 as well as the 2.67-3.09(1) Å Sm-(l 3 -Cl) distances in (C 5 H 5 ) 12 Sm 12 (l 3 -Cl) 24 [31]. The Sm(1)-(C 5 Me 5 ring centroid) distance of 2.379 Å is shorter than the 2.43-2.47 Å seen in (C 5 Me 5 ) 2 SmCl(THF) [25], but similar to the 2.376 Å observed for the samarium with one (C 5 Me 5 ) 1À ligand in [(C 5 Me 5 ) 2 Sm](lCl) 6 …”

The Striking Influence of Intramolecular Lanthanoid–π–Arene Interactions on the Structural Architecture of the Homoleptic Aryloxolanthanoid(II) Complexes [Eu2(Odpp)(-Odpp)3] and [Yb2(Odpp)2(-Odpp)2] and the YbII/YbIII Trimetallic [Yb2(-Odpp)3]+[Yb(Odpp)4] (Odpp=2,6-Diphenylphenolate)

“…[14] In addition, the hYb ± Oi distance (2.06 7 8) is smaller than the corresponding hNd ± Oi (2.18 7 ) and hEr ± Oi (2.08 2 ) distances, which correlates with differences in the ionic radii of the Ln 3 ions (i.e. [4a] Structurally characterised organometallic compounds combining lanthanoids in both the ii and iii oxidation states are very rare, specifically, [{Yb III (C 5 Me 5 ) 2 } 2 Yb II (m-CCPh) 4 ], [16] [Sm III (C 5 Me 5 ) 2 (m-C 5 H 5 )Sm II (C 5 Me 5 ) 2 ], [17] [{Yb III (C 5 Me 5 ) 2 -(m-F) 2 Yb II (C 5 Me 5 )} 2 ], [18] [Yb III (C 5 Me 5 ) 2 (m-F)Yb II (C 5 Me 5 ) 2 ], [19] and [Yb III Ph 2 (thf)(m-Ph) 3 Yb II (thf) 3 ]. [12] Since the ionic radius of Yb 2 is approximately 0.13 larger than Yb 3 , [12] the above distances unambiguously define the ytterbium in the anion as trivalent.…”