Synthesis and characterization of pentaphenyldiytterbium Ph2Yb(THF)(μ-Ph)3Yb(THF)3

Synthesis and Structures of the First Cationic Perfluoroaryllanthanoid(II) Complexes

“…The two C 6 F 5 groups are asymmetrically bound to Yb, each having one of the ortho-fluorines tilted toward the metal (as evidenced by narrow C-C-Yb angles 4 ] intramolecular LnÀF bonds are in the range 2.579(2)-2.749(2) ä, [31] well (1) Yb (2)ÀC (25) 2.569(9) 403(4), 2.158(3) ä). [32] Arguably, the YbÀs-aryl linkage in the latter is lengthened due to the bulky 2,6-mesityl substituents, and indeed this and the current YbÀC bond lengths are at the long end of the range for the terminal unsubstituted Ph groups of six-coordinate [YbPh 3 (thf) 3 ] [14,33] and [Yb III Ph 2 (thf)(m-Ph) 3 Yb II (thf) 3 ] (2.39(6)±2.46(4) ä) [34] despite the higher coordination numbers of the last two compounds. Longer Yb III ÀN(SiMe 3 ) 2 bonds than in 3 were observed in four-coordinate [Yb{N(SiMe 3 ) 2 } 2 (NPh 2 ) 2 Na(thf) 2 ] (2.216(4) ä [35] ), implying that the anion in 3 is not sterically overcrowded (sum of steric coordination numbers [28] of the ligand set is 6.9).…”

Element 70 – Ytterbium

“…Although Yb(Ph)I cannot be isolated, it is an excellent source of pyrazolato-and formamidinato-ytterbium complexes by reaction with 3,5-diphenylpyrazole [41a] and N,N 0 -diaryl-formamidines [41b] at low temperatures. Well-characterised alkyl-and aryl-ytterbium compounds include [Li(tmed 3 )][YbMe 6 ] (tmed¼ N,N 0 -tetramethylethane-1,2-diamine), [42] [YbPh 3 (thf) 3 ], [43] the mixed oxidation state [Yb III Ph 2 (thf)(p-Ph) 3 Yb II (thf) 3 ], [44] [Yb(C 6 F 5 ) 2 (thf) 4 ], [10,43b,45] and [Yb(CH 2 t Bu) 3 (thf) 2 ]. [46] Synthetic routes used to prepare organoytterbium compounds include metathesis, [2,33] redox transmetallation with mercurials [10,11,[43][44][45] and organothallium compounds, [47] protolysis for cyclopentadienyls, [33] and redox transmetallation/protolysis for cyclopentadienyls.…”

“…Well-characterised alkyl-and aryl-ytterbium compounds include [Li(tmed 3 )][YbMe 6 ] (tmed¼ N,N 0 -tetramethylethane-1,2-diamine), [42] [YbPh 3 (thf) 3 ], [43] the mixed oxidation state [Yb III Ph 2 (thf)(p-Ph) 3 Yb II (thf) 3 ], [44] [Yb(C 6 F 5 ) 2 (thf) 4 ], [10,43b,45] and [Yb(CH 2 t Bu) 3 (thf) 2 ]. [46] Synthetic routes used to prepare organoytterbium compounds include metathesis, [2,33] redox transmetallation with mercurials [10,11,[43][44][45] and organothallium compounds, [47] protolysis for cyclopentadienyls, [33] and redox transmetallation/protolysis for cyclopentadienyls. [48] In summary, ytterbium is one of the most versatile lanthanoid elements, with two readily accessible oxidation states, strong Lewis acidity in the trivalent state, versatile coordination chemistry in both oxidation states, and attractive organometallic chemistry.…”

Metall-π-Aren-Wechselwirkungen in den Kristallstrukturen von zwei Lewis-Donor-freien Arylbis(cyclopentadienyl)lanthanoiden

“…Die Lanthanoidatome in 1 und 2 weisen g 5 -koordinierte Cyclopentadienylliganden und eine g 1 -Bindung zum ipso-Kohlenstoffatom des Arylsubstituenten auf. In Abha È ngigkeit von der Gro È ûe des Mit einem Wert von 241,0 pm liegt die Yb±C1 Bindungsla È nge im selben Bereich wie die terminalen Yb±C-Absta È nde (Mittelwert 242 pm) im gemischtva-lenten Komplex Ph 2 (thf)Yb(l-Ph) 3 Yb(thf) 3 [7]. Etwas kleinere Absta È nde von 237,9 pm (Mittelwert) wurden im Anion [Yb{CH(SiMe 3 ) 2 } 3 Cl] ± [8] beobachtet.…”

“…(2). Die Synthese erfolgt entsprechend der Vorschrift fu È r Komplex 1 aus SmCp 3 (1,35 g, 3,9 mmol) und LiAr* (1,25 g, 3,9 mmol) 3,29 (s,12 H,7,80 (d,2 H,9,05 (t,1 H, H 3 ), 10,95 ppm (s,10 H,Cp). 13 …”