Alkali Metal Organometallics – Structure and Bonding

Ruhlandt‐Senge, Karin; Henderson, Kenneth W.; Andrews, Philip C.

doi:10.1016/b0-08-045047-4/00034-0

Cited by 12 publications

(14 citation statements)

References 487 publications

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“…The complex contains formal Li-N amido bonds in the range 1.967(3) to 2.064(3) A ˚(Table 1). These are comparable to those in previously characterised s-bonded Li amides 17,[25][26][27] and also in the related lithiated Scho¨llkopf's bis-lactim ethers, ranging from 1.965(3) to 2.089(5) A ˚.7,8 Each methoxy group acts as an internal donor, binding to a different Li cation to that of its corresponding N. The Li-O Me bond distances range from 1.975(3) to 2.059(3) A ˚, which is within the expected range of Li-O dative bonds. 8,28 This compares well with the chiral Li aza-enolate complex Li-2-acetylnaphthalene-SAMP-hydrazone (SAMP = (S)-1-amino-2-methoxymethylpyrrolidine), which has an internal solvating methoxy group with a Li-O bond length of 1.982(3) A ˚.29 Due to this internal solvation, only two thf molecules are incorporated into the 'tetrameric' structure.…”

Section: Solid-state Structuressupporting

confidence: 87%

Homo- and heteroanionic alkali metal aza-enolate aggregates derived from o-methylvalerolactim ether

2010

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The reaction of o-valerolactim ether with BuM (M = Li, Na, K) in the presence of the Lewis donors thf, tmeda, pyridine and pmdta resulted in the crystallisation and structural characterisation of a series of homo-and heteroanionic aggregates, which are also either homo or heterobimetallic. All the structures incorporate an aza-enolate (1-aza-allyl) anion (=R) derived from deprotonation of the lactim ether at the a-C, and its subsequent electronic rearrangement such that the metal bonds to the amido N. Lithiation resulted in crystals of [R 3 {R(Me 2 SiO)}Li 4 Á(thf) 4 ], 1, with Me 2 SiO À incorporated from the base induced decomposition of silicone grease; the linked dimer [R 4 Li 4 Á(tmeda) 3 ], 2, which has both terminal and bridging tmeda molecules; the octanuclear cluster [R 6 -m 6 -O-Li 8 Á(pyr) 2 ], 3, which is constructed around an O 2À anion; and [R(CH 2 QCHO) 2 Li 3 Ápmdta] 2 , 4, which incorporates lithium ethenolate, the base induced decomposition product of thf. Sodiation resulted in crystals of the simple dimeric complex [RNaÁtmeda] 2 , 5, while potassiation resulted in the heterobimetallic cluster [R(MeO)KLiÁ(tmeda)] 4 , 6, incorporating a MeO À anion due to its nucleophilic displacement from the valerolactim ether as MeOK by n Bu and subsequent anion exchange with t BuOLi. Solution NMR studies on the reaction between RH and t BuLi in the absence of a Lewis donor revealed that both the rate of deprotonation at the a-carbon and nucleophilic substitution of the ether functionality decrease substantially. The cyclic 2-t Bu-imine, as the thermodynamic product, becomes the dominant product, indicating that a Lewis donor solvent is necessary for efficient deprotonation to occur.

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Section: Solid-state Structuressupporting

confidence: 87%

Homo- and heteroanionic alkali metal aza-enolate aggregates derived from o-methylvalerolactim ether

2010

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“…1 A long-standing problem in the characterization of chalcogenalkali complexes stems from their poor solubility, tendency toward aggregation, inherent decomposition, and the formation of amorphous solids. 2 Since these functionalities serve as single-source precursors to semiconducting metal chalcogenides, 3 quantum dots, 4 gas-phase and in-solution deposition methods of metal chalcogenide films, and useful transfer reagents, 5,6 the quest for novel chalcogen-alkali compounds underscores their relevance. The structural chemistry of metal-alkali alkoxides and aryloxides has been widely studied, as opposed to that of their heavier chalcogen congeners.…”

Section: Introductionmentioning

confidence: 99%

“…The structural chemistry of metal-alkali alkoxides and aryloxides has been widely studied, as opposed to that of their heavier chalcogen congeners. 2,7 As far as heavier chalcogen-alkali complexes are concerned, the use of multidentate donors such as crown ethers leads to the stabilization of [M(18-crown-6)(thf) 2 ][SMes*] (M ) Na, K; Mes* ) 2,4,6-t Bu 3 C 6 H 2 ; THF ) tetrahydrofuran) thiolates and the (thf) 2 ][SeMes*] selenolate. 8 It was found that these compounds can behave in the solid state as separated or as contact ions.…”

Section: Introductionmentioning

confidence: 99%

Structural Variety of Alkali Metal Compounds Containing P−E−M (E = S, Se; M = Li, Na, K) Units Derived from Nitrogen Rich Heterocycles

et al. 2009

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The preparation of novel alkali metal chalcogenides supported by multidentate nitrogen rich ligands is reported. Treatment of the ligand precursors [H{(4,5-(P(E)Ph(2))(2)tz}] (E = S (1a), Se (1b)) with organolithium reagents or elemental sodium and potassium in tetrahydrofuran (THF) leads to the isolation of 2-7 in high yields. These compounds were characterized by elemental analysis, IR spectroscopy, mass spectrometry, solution and solid-state multinuclear NMR spectroscopy, and single crystal X-ray diffraction analysis. In the solid state, 2, 4, and 5 are dimers that contain bimetallic six-membered (M(2)N(4)) rings (M = Li, Na). In 3, the discrete monomer [Li{4,5-(P(Se)Ph(2))(2)tz}(thf)(2)] (tz = 1,2,3-triazole) contains a five-membered CPSeLiN ring which adopts an envelope conformation. The polymeric arrangement [K{4,5-(P(S)Ph(2))(2)}tz](infinity) in 6 displays different bonding modes based on the hapticity of the ligand upon binding to the potassium atom. In compounds 2-6, the presence of secondary bonding features the alkali metal chalcogen bonds.

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“…The alkali metals Li, Na, and K show a multifaceted coordination chemistry. This is largely due to the relatively high ionic character of their bonding interactions, which results in a pronounced flexibility in terms of coordination numbers and geometries . In addition, these metals have only a moderate preference for bonding interactions with either hard or soft donor functionalities (e.g., O - or N -based donors vs arenes). , Consequently, the coordination chemistry of alkali metal complexes of monoanionic, ditopic ligands with hard and soft binding sites can be challenging to predict.…”

Section: Introductionmentioning

confidence: 99%

Rationalizing the Effect of Ligand Substitution Patterns on Coordination and Reactivity of Alkali Metal Aminotroponiminates

Hanft

Lichtenberg

2018

Organometallics

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A small series of alkali metal aminotroponiminates (ATIs), [M-(ATI Ph/Ph )(thf) n ], have been synthesized and fully characterized (M = Li, Na, K). All of these compounds adopt coordination modes that differ from those reported for derivatives with a slightly varied substitution pattern at the ATI ligand (one or two of the N-bound Ph groups substituted by iPr groups). This leads to an unprecedented ATI coordination mode for the potassium compound [K(ATI Ph/Ph )] and an unusual Li•••Ph interaction for the lithium compound [Li(ATI Ph/Ph )]. The influence of the substitution pattern at the ATI ligand on the shape and energy of the frontier orbitals of its sodium complexes has been rationalized by theoretical methods and correlated with experimental results. Analytical techniques applied in this work include NMR spectroscopy, single crystal X-ray diffraction, and DFT calculations.

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Alkali Metal Organometallics – Structure and Bonding

Cited by 12 publications

References 487 publications

Homo- and heteroanionic alkali metal aza-enolate aggregates derived from o-methylvalerolactim ether

Homo- and heteroanionic alkali metal aza-enolate aggregates derived from o-methylvalerolactim ether

Structural Variety of Alkali Metal Compounds Containing P−E−M (E = S, Se; M = Li, Na, K) Units Derived from Nitrogen Rich Heterocycles

Rationalizing the Effect of Ligand Substitution Patterns on Coordination and Reactivity of Alkali Metal Aminotroponiminates

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