The crystal structure of N-lithiohexamethyldisilazane, [LiN(SiMe3)2]3

Heterobimetallic complexes of lanthanide and lithium metals with dianionic guanidinate ligands: Syntheses, structures and catalytic activity for amidation of aldehydes with amines

“…The three Li-N bond distances in both 5 and 6 are comparable and the average distances of 1.978(16) Å for 5 and 1.996(17) Å for 6 are in the range of single Li-N bond (1.96 Å). The values are also comparable to those found in lithium amides [Li(N(TMS) 2 ] 3 ) [45,46] and [{Li(N(TMS) 2 }(OEt 2 )] 2[45]. Furthermore, the average C-N(Li) (C 6 H 4 p-Cl) bond distances of 1.405(9) Å for 5 and 1.396(9) Å for 6 are consistent with a CN single bond.…”

Structural Characterization of Lithium and Sodium Bulky Bis(silyl)amide Complexes

“…During the synthesis of 1 crystals suitable for single crystal X-ray diffraction were grown and the solid-state structure was determined (see below). The lithium bis(silyl)amides [Li{μ-N(Si t BuMe 2 )(SiMe 3 )}] 2 ( 2 ), [Li{μ-N(Si i Pr 3 )(SiMe 3 )}] 2 ( 3 ), [Li{N(Si t BuMe 2 ) 2 }{μ-N(Si t BuMe 2 ) 2 }Li(THF)] ( 4 ), [Li{N(Si i Pr 3 )(Si t BuMe 2 )}(DME)] ( 6 ) and [Li{N(Si i Pr 3 ) 2 }(THF)] ( 7 ) were isolated by recrystallization from various solvents following straightforward synthesis from the parent amine and n BuLi, using analogous procedures to the synthesis of LiN′′ [8,9] (Scheme 1). On one occasion during the synthesis of 4 several crystals of the ‘ate’ complex [Li 2 {μ-N(Si t BuMe 2 ) 2 }(μ- n Bu)] 2 ( 5 ) formed and a trace amount of [Li{N(Si i Pr 3 ) 2 }(THF) 2 ] ( 8 ) was identified during the recrystallization of 7 .…”

“…Although these reagents are often used in situ, the solvent-free solid-state structures of the lighter group 1 salts LiN′′ [8,9], NaN′′ [10] and KN′′ [11] have been reported previously. Interestingly, although synthetic routes to alkali metal bis(silyl)amides with larger R groups, {MN(SiR 3 ) 2 } (R = Me, t Bu, i Pr, etc.…”

Structural Elucidation of tmeda‐Solvated Alkali Metal Diphenylamide Complexes

“…[67] For 1, its respective 7 Li NMR spectrum also supports this conclusion as only one resonance (δ = 0.88 ppm) is observed. Higher oligomeric forms (trimer, [30,[68][69][70][71][72] tetramer, [73,74] hexamer [75] and polymer [76] ) of Li amides are known; however, they tend to exist only in the absence of donor solvents.…”

“…On the other hand, 3 is not soluble in C 6 Primarily to gain a greater understanding of these synthetic endeavours, the structural chemistry of the alkali metal amides has maintained a high level of interest, since the first reported solid-state structure of an alkali metal amide {that of trimeric [Li(hmds)] 3 } in 1969. [30,31] Alkali metal diphenylamide complexes have been extensively studied. The solution structure of LiNPh 2 in thf (in the presence/absence of LiBr) has been comprehensively studied by Collum.…”