Chelate Stabilization of a Monomeric Lithium Tellurolate

Abstract

Isolable, well‐defined alkali metal tellurolates—of interest for organic synthesis as well as for the production of transition metal tellurides—are only known with bulky organic groups. By lithiation and chalcogenation, the tellurolate 3 has now been obtained from 1 in quantitative yield via the intermediate 2. Subsequent reactions demonstrate the usefulness of such tellurolates.

Structural Aspects of Lithium Arenethiolate Complexes with Intramolecular Coordinating Amine Donors

“…25 Moreover, the aggregation state of lithium arenethiolates and arenetellurolates is also very sensitive to the addition of external donor ligands such as THF or dimethoxyethane and recently a lithium arenetellurolate derived from ((dimethylamino)methyl)ferrocene was reported to be monomeric as a result of auxiliary coordination of dimethoxyethane. 26 Furthermore, pure lithium thiophenolate is polymeric, but addition of donor molecules such as THF and pyridine can result both in polymers with a lower bridging character of the arenethiolate sulfur atom, e.g., [ Hexagonal prismatic structures such as that found for 3 are known for some lithium enolates, 28 but few precedents exist for hexagonal planar structures like that of 4. To our knowledge the only related example is that of the lithium phenolate [Li-{OC 6 H 2 (CH 2 NMe 2 ) 2 -2,6-Me-4}] 3 , which forms a structure having a planar Li 3 O 3 6-membered ring.…”

Lithium Alkylselenolates and -tellurolates − A Solid-State and Solution Structural Study

“…[10] and 2.122(2) Å in [CpFe{C 5 H 3 -(CH 2 NMe 2 )TeLi·DME}]. [15] The LiϪTeϪLi bond angles [both of which are 68.2(2)°] are more acute than those observed [75.1(1)°] in the only other dimeric lithium tellurolate [(DME)LiTeSi(SiMe 3 ) 3 ] 2 , [9] and the mean CϪTeϪLi bond angle in 2 is 95.0°[range 93.5(2) to 97.2(2)°].…”

“…[4] Moreover, the majority of studies to date have utilised sterically bulky ligands, such as substituted silyl chalcogenolates (R 3 SiX Ϫ ; R ϭ Me, SiMe 3 ; X ϭ Se, Te) [5Ϫ9] or substituted aromatics (Mes*X Ϫ ; Mes* ϭ 2,4,6-tBu 3 C 6 H 2 ; X ϭ Se, Te) [10Ϫ12] so as to confer extra kinetic stability upon the resulting complex. To the best of our knowledge the only other examples of alkali-metal organochalcogenolates to be structurally characterised are the 2,2Ј-bipyridine complexes [PhSeLi·bipy] 2 and [2-PyrSeLi·bipy] 2 , [13] the phenylacetyl selenolate PhCϵCSe-Li·TMEDA·THF [14] and the heterobimetallic species [CpFe{C 5 H 3 (CH 2 NMe 2 )TeLi·DME}], [15] [(C 5 H 5 ) 2 Lu(µ-SePh) 2 Li·2THF] [16] and [(py) 2 Yb(SePh) 2 (µ-SePh) 2 Li(py) 2 ] (py ϭ pyridine). [17] In order to confront this lack of structural knowledge, particularly of the less sterically demanding ligands, we report here the first solid-state characterisation of both a lithium alkylselenolate (nBuSeLi·TMEDA) 2 (1) and -tellurolate (nBuTeLi· TMEDA) 2 structures of a lithium alkylselenolate and -tellurolate and giving a unique insight into the coordination chemistry of the less sterically demanding chalcogenolate ligands.…”

Crystal structure of bis{μ-2-[(dimethylamino)methyl]ferroceneselenolato}bis[chloridopalladium(II)]

“…For the structure of the dinuclear palladium complex [PdCl-(C 9 H 12 NSe)] 2 , see: Chakravorty et al (2012); Pop et al (2013). For the synthesis of lithium [2-(N,N 0 -dimethylamino)methyl]ferroceneselenolate, see: Gornitzka et al (1992 Table 1 Selected geometric parameters (Å , ).…”