“…15). 90 The authors postulated that 51 formed via the association of in situ-generated "[Yb(SnPh 3 )(Ph)(THF) n ]" with "[Yb(Ph) 2 (THF) 3 ]" to alleviate steric unsaturation. The Yb-Sn length in 51 is 3.379(1) A, which is longer than the mean Yb-Sn distance previously reported for 50 (3.305(1) A Fig.…”
Section: D2 Tinmentioning
confidence: 99%
“…The mechanism of formation of 51 was proposed by the authors to proceed by a 2 electron transfer from [Yb(C 10 H 8 )(THF) 2 ], generating neutral C 10 H 8 and reductively cleaving one C Ph -Sn bond, formally resulting in {Ph 3 Sn} and {Ph} anions and a solvated Yb(II) cation. Various ligand scrambling processes can occur by Schlenk-type equilibria, with one eventuality leading to complex 50 and another outcome yielding 51 90. In 1993 Bochkarev and co-workers reported the reaction of Me 3 SnCl with either…”
The last three decades have seen a significant increase in the number of reports of f-element carbon chemistry, whilst the f-element chemistry of silicon, germanium, tin, and lead remain underdeveloped...
“…15). 90 The authors postulated that 51 formed via the association of in situ-generated "[Yb(SnPh 3 )(Ph)(THF) n ]" with "[Yb(Ph) 2 (THF) 3 ]" to alleviate steric unsaturation. The Yb-Sn length in 51 is 3.379(1) A, which is longer than the mean Yb-Sn distance previously reported for 50 (3.305(1) A Fig.…”
Section: D2 Tinmentioning
confidence: 99%
“…The mechanism of formation of 51 was proposed by the authors to proceed by a 2 electron transfer from [Yb(C 10 H 8 )(THF) 2 ], generating neutral C 10 H 8 and reductively cleaving one C Ph -Sn bond, formally resulting in {Ph 3 Sn} and {Ph} anions and a solvated Yb(II) cation. Various ligand scrambling processes can occur by Schlenk-type equilibria, with one eventuality leading to complex 50 and another outcome yielding 51 90. In 1993 Bochkarev and co-workers reported the reaction of Me 3 SnCl with either…”
The last three decades have seen a significant increase in the number of reports of f-element carbon chemistry, whilst the f-element chemistry of silicon, germanium, tin, and lead remain underdeveloped...
“…77 The dinuclear nature of 3 represents the first example of a dinuclear samarium complex bridged by an η 1 :μ 2 -phenyl group and only the third example of the whole lanthanide series with a similar bridging fragment. 78,79 Although the NMR spectral parameters of 3 indicate this complex is not strongly paramagnetic, analysis of this complex by air-sensitive SQUID measurements to determine its magnetic properties is still of interest, and the potential of the bridging system to evoke magnetic exchange coupling between samarium centres will be undertaken in due course.…”
Section: Synthesis and Cyclometalation Reactivity Of Organosamarium D...mentioning
The pyrrole-based ligand N,N'-((1H-pyrrole-2,5-diyl)bis(diphenylphosphoranylylidene))bis(4-isopropylaniline) (HL(B)) can be deprotonated and coordinated to yttrium and samarium ions upon reaction with their respective trialkyl precursors. In the case of yttrium, the resulting complex [L(B)Y(CH2SiMe3)2] (1) is a Lewis base-free monomer that is remarkably resistant to cyclometalation. Conversely, the analogous samarium complex [L(B)Sm(CH2SiMe3)2] is dramatically more reactive and undergoes rapid orthometalation of one phosphinimine aryl substituent, generating an unusual 4-membered azasamaracyclic THF adduct [κ(4)-L(B)Sm(CH2SiMe3)(THF)2] (2). This species undergoes further transformation in solution to generate a new dinuclear species that features unique carbon and nitrogen bridging units [κ(1):κ(2):μ(2)-L(B)Sm(THF)]2 (3). Alternatively, if 2 is intercepted by a second equivalent of HL(B), the doubly-ligated samarium complex [(κ(4)-L(B))L(B)Sm] (4) forms.
“…Treatment of a THF solution of Ph 4 Sn with (C 10 H 8 )Yb(THF) 2 at room temperature results in the formation of two compounds. Yellow (Ph 3 Sn) 2 Yb(THF) 4 was obtained from an ether solution (Yb−Sn = 331 pm, Sn−Yb−Sn = 165°), whereas dark-ruby, almost black (Ph 3 Sn)Yb(THF) 2 (μ-Ph) 3 Yb(THF) 3 ( 4 ) was isolated from ether−THF (Yb−Sn = 338 pm). , …”
Section: 3 Complexes With Heavier Group 14 Elementsmentioning
Over the years one major challenge has remained in organolanthanide chemistry: the synthesis of homoleptic alkyl and aryl complexes. The simplest organometallic compounds of the rare earths are the species LnR 2 or LnR 3 with the rare earth metals in their common oxidation states Ln 2+ and Ln 3+ which imply the coordination of only two or three ligands to the metal center. This is usually insufficient to meet the lanthanides' demands of steric saturation through high coordination numbers.Hence for a long time, only indirect evidence could be found for the existence of simple homoleptic organolanthanide compounds; the isolation and characterization of compounds belonging to this class were first achieved recently using pentafluorophenyl for Ln 2+ derivatives 12 and very bulky alkyl ligands for Ln 3+ species. [13][14][15] Especially for alkyls, very little structural data are available for compounds without any trimethylsilyl-substituted ligands which generally ensure higher stability. But nevertheless, due to the difficulties of their synthesis and their high reactivity alkyls and aryls still represent an interesting class of compounds. 16
Homoleptic σ-Alkyl ComplexesShortly after the synthesis of the first divalent solvent-free Ln alkyl, [(Me 3 Si) 3 C] 2 Yb, 17 the Eu analogue was prepared similarly by the reaction of EuI 2 and KC(SiMe 3 ) 3 in benzene. 18 It also features the bent structure displayed by the Yb complex but with a slightly smaller C-Eu-C angle (C-Eu-C ) 136°, C-Yb-C ) 137°) and longer Eu-C bonds (Eu-C ) 261 pm, Yb-C ) 249/250 pm). Salt metathesis was then again applied successfully to synthesize the first divalent Sm alkyl, Sm[C(SiMe 3 ) 2 (SiMe 2 OMe)] 2 (THF) Frank T. Edelmann was born in Hamburg, Germany, in 1954. He studied chemistry from 1974 to 1979 at the University of Hamburg, where he obtained his Diplom in 1979 and doctoral degree in 1983. His Ph.D. thesis entitled "The chemistry of the tricarbonyl(fulvene) chromium complexes" was carried out under the supervision of Prof. Ulrich Behrens. This was followed by two years (1983−1985) of postdoctoral research as a Feodor Lynen Fellow of the Alexander-von-Humboldt Foundation in the groups of Professors Josef Takats (
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