Trimeric dibenzylamidolithium and its dimeric diethyl ether and hexamethylphosphoramide complexes: structural and theoretical studies of reactive organonitrogen–lithium oligomers

Barr, David P.; Clegg, William; Mulvey, Robert E.; Snaith, Ronald

doi:10.1039/c39840000285

Cited by 98 publications

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“…The lowest-energy optimized monomeric structure ( Figure S8 in the Supporting Information) was calculated to be considerably higher in energy than I (+ 61.27 kcal mol À1 for two monomeric units), making the formation of monomeric species seem unlikely. However, it is possible that any [CuLiMes{N(CH 2 Ph) 2 }] monomeric complex would contain additional stabilization from Li···HC interactions, similar to those previously reported for [Li{N(CH 2 Ph) 2 }] n , [19,20] thus making its formation more favorable than that for the calculated [CuLiMe(NH 2 )] model system. In summary, the first solid-state structure of an organoamidocuprate has been presented and shown to form a headto-tail dimeric aggregate consistent with previous theories.…”

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confidence: 66%

Structural Studies on a Lithium Organo‐Amidocuprate in the Solid State and in Solution

2007

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confidence: 66%

Structural Studies on a Lithium Organo‐Amidocuprate in the Solid State and in Solution

2007

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“…[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.…”

Section: Preparation and Solution Structuresmentioning

confidence: 99%

Structural Elucidation of tmeda‐Solvated Alkali Metal Diphenylamide Complexes

et al. 2009

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Lithium, sodium and potassium salts of diphenylamine have been prepared by using a deprotonative route and characterised in both, solid state (by X‐ray crystallography) and solution (by NMR spectroscopic studies). In each case the metal atom's coordination sphere is completed by coordination to the synthetically important co‐ligand N,N,N′,N′‐tetramethylethylenediamine (tmeda). Complexes 1 and 2 [{(tmeda)M(NPh2)}2] (M = Li for 1, Na for 2) can be prepared by treating 1 mol.‐equiv. of the parent amine with an equimolar quantity of nBuM and tmeda in hexane solution. In the solid state, 1 and 2 are essentially isostructural, being dimeric with a four‐atom M–N–M–N framework. The coordination sphere of each M atom is completed by a bidentate tmeda molecule. Complex 3 [{(tmeda)3/2K(NPh2)}2] has been prepared in a similar way to 1 and 2 except that benzylpotassium has been utilised as the metallating agent. In addition, 4 mol‐equiv. of tmeda is required to fully solubilise the heavy alkali metal amide mixture. In the solid state, 3 exists as a polymeric array of dinuclear K–N–K–N rings. Akin to 1 and 2, the K atom is coordinated to a bidentate tmeda molecule; however, each K atom is also bound to another tmeda molecule that acts as a monodentate bridge, thus producing the coordination polymer. Crystalline 1 and 2 are soluble in C6D6; hence, NMR spectroscopic studies could be performed. These show that the solid‐state structure appears to stay intact in arene solution. On the other hand, 3 is not soluble in C6D6; so solution studies have been performed in [D8]thf. These studies reveal that 3 readily looses tmeda during in‐vacuo isolation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

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“…In the case of the u n i y e K(3) centre in 3, the deviations are 1.700 and 2.134 A. The CiN3 rings themselves are not strictly planar, though only in 3 does the distortion appear significan!, the largest mean deviation of the ring atoms being 0.083 A for N(l)C(l)N(2)C(15)N(3)C(8), which significantly binds to K (3) [through N( l)]. Attached Ph substituents tilt out of the C3N3 ring planes as evidenced by torsion angles of the type N(I)C(8)C(9)C(14) in 2 (31.7"): the ranges of like torsion angles are 20.…”

Section: Potassio Triazines Belonging To the Potassate Familymentioning

confidence: 98%

“…The following year witnessed the structure of the ketimine-based 'ate, [Li(HMPA),]+[R6Li5(HMPA)J-(R = N=CPh2), with its contrasting pentanuclear clustered anion [3]. Since then a modest number of other 'ate compositions have appeared including the sodium sodate [Na(TM EDA)2(Et20)]'-[R2Na]-[R = C(SiMe&]i41 and the sodium lithate [Na(THF),Jf[R2Li]-[R = (2-pyr)CH(2-pyr)]rs1.…”

Section: Introductionmentioning

confidence: 99%

“Potassium Potassates” Based on Dihydrotriazinide Ligands: Syntheses, Crystal Structures, and Comparison with Other Alkali Metal Dihydrotriazinide Compounds

et al. 1997

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A series of dihydro‐s‐triazinidopotassium complexes have been synthesised and structurally characterised by X‐ray diffraction. Two of them, the sesqui‐pyridine solvate 2 and the mono‐THF solvate 3, can be classified in formal terms as “potassium potassates” in conforming to the structural pattern established previously for the sesqui‐THF solvate 1, the first reported ate of this type. Formally complex [(R2K)−] anions are linked to K+ cations in polymeric, zig‐zag chain arrangements. Solvate 3 also possesses a unique RK coordination as a direct result of having fewer solvent ligands. DMSO analogue 4 deviates from this uniformity in adopting a centrosymmetric, dimeric (OK)2 ring structure featuring both terminal and bridging DMSO ligands. The dihydro‐s‐triazinidosodium tris(THF) solvate 5 is found to be a monomer. For comparative purposes, the metal‐free, parent triazine molecule 6 has also been subjected to an X‐ray crystallographic study: it displays a 1,2‐dihydro ring setup as opposed to the 1,4‐dihydro alternative existing in the metallo examples. Triazine 6 is also found to form a N–H…Br bridge in the dimeric structure of the lithium bromide bis (THF) solvate 7, a suspected hydrolysis product from the reaction of dihydro‐s‐triazinidolithium 8 and magnesium bromide bis(ether) adduct.

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Trimeric dibenzylamidolithium and its dimeric diethyl ether and hexamethylphosphoramide complexes: structural and theoretical studies of reactive organonitrogen–lithium oligomers

Cited by 98 publications

References 0 publications

Structural Studies on a Lithium Organo‐Amidocuprate in the Solid State and in Solution

Structural Studies on a Lithium Organo‐Amidocuprate in the Solid State and in Solution

Structural Elucidation of tmeda‐Solvated Alkali Metal Diphenylamide Complexes

“Potassium Potassates” Based on Dihydrotriazinide Ligands: Syntheses, Crystal Structures, and Comparison with Other Alkali Metal Dihydrotriazinide Compounds

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