Lithium Derivatives Research Articles

Bringing the state back in the lithium triangle: An institutional analysis of resource nationalism in Chile, Argentina, and Bolivia

International efforts to tackle climate change have ignited a global surge in demand for the “critical metals” that are used in the production of lithium-ion batteries and electric vehicles (EVs). Among them, lithium represents a critical strategic component that is concentrated in only a limited number of extractive zones. In theory, limited availability and strong demand creates favourable conditions for producer states. In practice, many states have struggled to nationalize the production of battery-grade lithium, reflecting the dominant role that multinational corporations play in the sector. This paper explores the strategies that producer states in Chile, Argentina, and Bolivia have used to navigate this rapidly changing dynamic, making the case that the recent surge in demand for battery metals has created new opportunities for challenging the oligopoly of multinational capital but the ability of governments to reorient production linkages for enhancing incomes, technical capacity, and economic opportunity in the production of lithium derivatives remains structurally and historically constrained by the institutional legacies of nationalization and social mobilization that vary across the three states. Drawing upon the “political settlements” literature, we contend that national and subnational efforts to exert greater control over the lithium sector can be attributed to the institutional legacy of political contestation and the role of social actors in crafting new power configurations that challenge dominant state-business coalitions.

Diversity of Structures and Bonding in Alkali Metal Ureaphosphanes

AbstractWhile organoelement compounds of lithium, sodium and potassium have been much studied for decades and consequently have found forests of applications, those of the heavier alkali metals, rubidium and caesium would barely manage to fill a tree. However, recently the literature has seen some little growth spurts with these metals, hinting at a possible fertile future in areas such as homogeneous catalysis provided more work is put into their fundamental development. Here we report the synthesis and crystal structures of lithium, rubidium and caesium derivatives of the ureaphosphane Ph2PCH2CH2NHC(=O)NHPh, chosen because it offers O, N, P, and π‐coordination sites. Though one may expect such alkali metal compounds to be essentially similar, the caesium complex has novel features where Cs+ engages in a side‐on coordination to the C=O bond and in a weak bond to the P centre, both of which are absent in the Rb structure. Less surprisingly, the lithium derivative is tetrameric in contrast to the infinite networks of the rubidium and caesium structures. All alkali metal derivatives were made with deprotonating the ureaphosphane by a suitable base, including the sodium and potassium complexes though these two complexes could not be obtained in a crystalline form.

Mixed occupancy: the crystal structure of scheelite-type LiLu[MoO4]2

Coarse colorless single crystals of lithium lutetium bis[orthomolybdate(VI)], LiLu[MoO4]2, were obtained as a by-product from a reaction aimed at lithium derivatives of lutetium molybdate. The title compound crystallizes in the scheelite structure type (tetragonal, space group I41/a) with two formula units per unit cell. The Wyckoff position 4b (site symmetry \overline{4}) comprises a mixed occupancy of Li+ and Lu3+ cations in a 1:1 ratio. In comparison with a previous powder X-ray study [Cheng et al. (2015). Dalton Trans. 44, 18078–18089.] all atoms were refined with anisotropic displacement parameters.

Alkali metal reduction of crown ether encapsulated alkali metal cations.

[{SiNDipp}BeClM]2 ({SiNDipp} = {CH2SiMe2N(Dipp)}2; M = Li, Na, K, Rb) are converted to ionic species by treatment with a crown ether. Whereas the lithium derivative reacts with Na or K to provide [{SiNDipp}BeCl]-[M(12-cr-4)2]+ (M = Na, K), the resultant sodium species is resistant to reduction by potassium. These observations are rationalised by a hybrid experimental/theoretical analysis.

Synthesis and Complexation Study of New Aminoalkynyl−amidinate Ligands

AbstractThe current library of amidinate ligands has been extended by the synthesis of two novel dimethylamino‐substituted alkynylamidinate anions of the composition [Me2N−CH2−C≡C−C(NR)2]−(R =iPr, cyclohexyl (Cy)). The unsolvated lithium derivatives Li[Me2N−CH2−C≡C−C(NR)2] (1: R =iPr,2: R = Cy) were obtained in good yields by treatment ofin situ‐prepared Me2N−CH2−C≡C−Li with the respective carbodiimides, R−N=C=N−R. Recrystallization of1and2from THF afforded the crystalline THF adducts Li[Me2N−CH2−C≡C−C(NR)2] ⋅ nTHF (1 a: R =iPr,n=1;2 a: R = Cy,n=1.5). Precursor2was subsequently used to study initial complexation reactions with selected di‐ and trivalent transition metals. The dark red homoleptic vanadium(III) tris(alkynylamidinate) complex V[Me2N−CH2−C≡C−C(NCy)2]3(3) was prepared by reaction of VCl3(THF)3with 3 equiv. of2(75 % yield). A salt‐metathesis reaction of2with anhydrous FeCl2in a molar ratio of 2 : 1 afforded the dinuclear homoleptic iron(II) alkynylamidinate complex Fe2[Me2N−CH2−C≡C−C(NCy)2]4(4) in 69 % isolated yield. Similarly, treatment of Mo2(OAc)4with 3 or 4 equiv. of2provided the dinuclear, heteroleptic molybdenum(II) amidinate complex Mo2(OAc)[Me2N−CH2−C≡C−C(NCy)2]3(5; yellow crystals, 50 % isolated yield). The cyclohexyl‐substituted title compounds2 a,4, and5were structurally characterized through single‐crystal X‐ray diffraction studies.

Inhibition of Alkali Metal Reduction of 1‐Adamantanol by London Dispersion Effects

AbstractA series of alkali metal 1‐adamantoxide (OAd1) complexes of formula [M(OAd1)(HOAd1)2], where M=Li, Na or K, were synthesised by reduction of 1‐adamantanol with excess of the alkali metal. The syntheses indicated that only one out of every three HOAd1 molecules was reduced. An X‐ray diffraction study of the sodium derivative shows that the complex features two unreduced HOAd1 donors as well as the reduced alkoxide (OAd1), with the Ad1 fragments clustered together on the same side of the NaO3 plane, contrary to steric considerations. This is the first example of an alkali metal reduction of an alcohol that is inhibited from completion due to the formation of the [M(OAd1)(HOAd1)2] complexes, stabilized by London dispersion effects. NMR spectroscopic studies revealed similar structures for the lithium and potassium derivatives. Computational analyses indicate that decisive London dispersion effects in the molecular structure are a consequence of the many C−H⋅⋅⋅H−C interactions between the OAd1 groups.

Inhibition of Alkali Metal Reduction of 1‐Adamantanol by London Dispersion Effects

AbstractA series of alkali metal 1‐adamantoxide (OAd1) complexes of formula [M(OAd1)(HOAd1)2], where M=Li, Na or K, were synthesised by reduction of 1‐adamantanol with excess of the alkali metal. The syntheses indicated that only one out of every three HOAd1 molecules was reduced. An X‐ray diffraction study of the sodium derivative shows that the complex features two unreduced HOAd1 donors as well as the reduced alkoxide (OAd1), with the Ad1 fragments clustered together on the same side of the NaO3 plane, contrary to steric considerations. This is the first example of an alkali metal reduction of an alcohol that is inhibited from completion due to the formation of the [M(OAd1)(HOAd1)2] complexes, stabilized by London dispersion effects. NMR spectroscopic studies revealed similar structures for the lithium and potassium derivatives. Computational analyses indicate that decisive London dispersion effects in the molecular structure are a consequence of the many C−H⋅⋅⋅H−C interactions between the OAd1 groups.

Hydrogen and Lithium Bonds-Lewis Acid Units Possessing Multi-Center Covalent Bonds.

MP2/aug-cc-pVTZ calculations were carried out on complexes wherein the proton or the lithium cation is located between π-electron systems, or between π-electron and σ-electron units. The acetylene or its fluorine and lithium derivatives act as the Lewis base π-electron species similarly to molecular hydrogen, which acts as the electron donor via its σ-electrons. These complexes may be classified as linked by π-H∙∙∙π/σ hydrogen bonds and π-Li∙∙∙π/σ lithium bonds. The properties of these interactions are discussed, and particularly the Lewis acid units are analyzed, because multi-center π-H or π-Li covalent bonds may occur in these systems. Various theoretical approaches were applied here to analyze the above-mentioned interactions—the Quantum Theory of Atoms in Molecules (QTAIM), the Symmetry-Adapted Perturbation Theory (SAPT) and the Non-Covalent Interaction (NCI) method.

Synthesis and reactivity of an anionic NHC-borane featuring a weakly coordinating silicate anion

We report herein the synthesis of a new NHC-stabilised borane complex featuring a weakly coordinating anion, namely a pentaorganosilicate, on the NHC backbone. The synthesis can be achieved from a zwitterionic abnormal silicate-imidazolium adduct by deprotonation with a strong base followed by quenching with a borane transfer agent. Alternatively, the IPr-BH3 complex can also be deprotonated and the resulting vinylanion is trapped by a tetravalent spirosilane. The first structural data on a lithium derivative of an anionic NHC-borane complex functionalized by a silicate have been obtained and reveal an interaction between the three hydrogens of the borane and the lithium cation. Assessment of the reactivity highlights the higher hydridicity of the anionic NHC-borane compared to the parent IPr-BH3. Finally, electronic properties of this new species have been evaluated by means of DFT calculations and the presence of the silicate on the NHC backbone raises the HOMO which can in part explain the high hydride-donor abilities. This is consistent with the smooth reduction of an aldehyde without Lewis acid additive.

The modulation of 9-Chloro-9-Phosphaalkenylchloro-9-Germafluorene reactivity through organolithium reagents

The reactivity of 9-chloro-9-phosphaalkenylchloro-9-germafluorene stabilized by the introduction of the germanium atom into a fluorenyl system, was tested in reaction with lithium derivatives as methyllithium, normal-, sec- and tert-butyllithium. The reactions underwent, depending on the used organolithium derivative, either with the alkylation of the germanium atom or through a lithiation of the carbon atom of the phosphaalkenyl unit, and the successive formation of a carbanion through elimination of LiCl followed by the dimerization of this intermediate species.

Preparation of double decker {Li3(Cl−)(Hhp)}22− dianions and H2TPCor− monoanions by deprotonation of free-base trithiododecaazahexaphyrin (H3Hhp) and triphenylcorrole (H3TPCor) macrocycles

Deprotonation of free-base [30]trithia-2,3,5,10,12,13,15,20,22,23,25,30-dodecaazahexaphyrin (hemihexaphyrazine, H3Hhp) and 5, 10, 15- triphenylcorrole (H3TPCor) macrocycles by an excess of lithium diethylamide, LiNEt2, in the presence of three equivalents of cryptand[2.2.2] has been studied. Crystallization of the obtained products after the reaction allows the isolation of crystalline {Cryptand[2.2.2](Li)}2{Li3Cl(Hhp)}2·6C6H4Cl2 (1) and {Cryptand[2.2.2](Li)} {H2TPCor)·0.5C6H4Cl2 (2) salts. Compound 1 is the first example of lithium derivative of hemihexaphyrazine which additionally coordinates one Cl− anion per three lithium ions. There are five (Li+)⋯(Cl−) contacts of 2.389(4)-2.456(4) Å length for two independent {Li3Cl(Hhp)}− anions. However, one contact elongates to 2.557(4) Å due to shift of Cl− anions towards two hydrogen atoms of cryptand[2.2.2] providing the formation of weak hydrogen (Cl−)⋯H(cryptand) bonds. Two {Li3Cl(Hhp)}− anions are arranged in the double decker {Li3Cl(Hhp)}22− structure due to that the Cl− anion of one Li3Cl(Hhp) unit forms additional weak (Li+)⋯(Cl−) contacts of 2.586–2.617(4) Å with two lithium ions of the second {Li3Cl(Hhp)}− unit. In contrast to H3Hhp, H3TPCor splits only one hydrogen atom at deprotonation in the same experimental conditions forming a planar H2TPCor− anion and, therefore, H3Hhp has higher acidity of central hydrogen atoms in comparison with H3TPCor. Deprotonation preserves diamagnetic state of pristine macrocycles in salts 1 and 2. Their optical properties are also discussed. DFT calculations were carried out for 1 to discuss aromaticity of the macrocycles, electronic structure and optical spectrum of 1.

A N-Phosphinoamidinato NHC-Diborene Catalyst for Hydroboration.

The use of the N-phosphinoamidinato NHC-diborene catalyst 2 for hydroboration is described. The N-phosphinoamidine tBu2PN(H)C(Ph)═N(2,6-iPr2C6H3) was reacted with nBuLi in Et2O to afford the lithium derivative, which was then treated with B2Br4(SMe2)2 in toluene to form the N-phosphinoamidinate-bridged diborane 1. It was reacted with the N-heterocyclic carbene IMe (:C{N(CH3)C(CH3)}2) and excess potassium graphite at room temperature in toluene to give the N-phosphinoamidinato NHC-diborene compound 2. It can stoichiometrically activate ammonia-borane and carbon dioxide. It also showed catalytic capability. A 2 mol % portion of 2 catalyzed the hydroboration of carbon dioxide (CO2) with pinacolborane (HBpin) in deuterated benzene (C6D6) at 110 °C (conversion >99%), which afforded the methoxyborane [pinBOMe] (yield 97.8%, TOF 33.3 h-1) and the bis(boryl) oxide [(pinB)2O]. In addition, 5 mol % of 2 catalyzed the N-formylation of secondary and primary amines by carbon dioxide and pinacolborane to yield the N-formamides (average yield 91.6%, TOF 25.9 h-1). Moreover, 2 showed chemoselectivity toward catalytic hydroboration of carbonyl compounds. In mechanistic studies, the B═B double bond in compound 2 activated the substrates, the intermediates of which then underwent hydroboration with pinacolborane to yield the products and regenerate catalyst 2.

Chiral N-tert-Butylsulfinyl Imines: New Discoveries.

In this account the reactions of chiral N-tert-butylsulfinyl imines with organometallic reagents such as organoalkaline (lithium, sodium, potassium and cesium derivatives), organomagnesium, organozinc, organoboron, organoaluminium, organoindium and organosilicon compounds is comprehensively described. The reactivity in all cases is derived to synthetic applications in order to prepare interesting organic nitrogenated molecules, especially in the field of alkaloid compounds.

Aromatic nucleophilic substitution: A case study of the interaction of a lithiated nitronyl nitroxide with polyfluorinated quinoline-N-oxides

A 4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl lithium derivative was found to react with 5,6,7,8-tetrafluoro- or 5,7,8-trifluoro-6-(trifluoromethyl)quinoline-N-oxides with the formation of products of aromatic nucleophilic substitution of the H atom at position 2 of the quinoline ring. The reaction regioselectivity is supported by the data of quantum-chemical calculations. Molecular and crystal structures of the obtained nitronyl nitroxides were solved by monocrystal X-ray diffraction analysis, and the nature of the radical was ascertained by electron spin resonance spectroscopy. Heterospin complexes of Cu(hfac)2 with the synthesized quinoline-substituted nitronyl nitroxides were prepared. According to X-ray diffraction analysis, seven-membered metallocycles are formed in the complexes owing to simultaneous coordination of the nitroxyl and N-oxide groups by the Cu atom.

Unusual sydnones based di- and trisilamacrocycles

The reactions of lithium derivatives of sydnones with 1,3-dichloro-1,1,3,3-tetramethyldisiloxane have been studied. The first representatives of sydnon-4-yl substituted disiloxanes and silicon macrocyclic derivatives of sydnones were obtained and their molecular structures were studied by X-Ray and 1H, 13C, 29Si, and 15N NMR spectroscopy.

Counterion Dependence of Dinitrogen Activation and Functionalization by a Diniobium Hydride Anion

AbstractWe report the synthesis of anionic diniobium hydride complexes with a series of alkali metal cations (Li+, Na+, and K+) and the counterion dependence of their reactivity with N2. Exposure of these complexes to N2 initially produces the corresponding side‐on end‐on N2 complexes, the fate of which depends on the nature of countercations. The lithium derivative undergoes stepwise migratory insertion of the hydride ligands onto the aryloxide units, yielding the end‐on bridging N2 complex. For the potassium derivative, the N−N bond cleavage takes place along with H2 elimination to form the nitride complex. Treatment of the side‐on end‐on N2 complex with Me3SiCl results in silylation of the terminal N atom and subsequent N−N bond cleavage along with H2 elimination, giving the nitride‐imide‐bridged diniobium complex.

Crystal structure and migration paths of alkaline ions in NaVPO4F.

A sample with a nominal composition 'NaVPO4F' is prepared by mechanochemically assisted solid-state synthesis using quenching. A detailed study of its crystal and local structure is conducted by means of XRD and FTIR and solid-state 31P NMR spectroscopies in comparison with Na3V2(PO4)2F3. It is shown that the as-prepared 'NaVPO4F' has a multiphase composition, including NaVPO4F as the main phase and Na3V2(PO4)2F3 and Na2.57V4P4O17F as the side products. The crystal structure of NaVPO4F is described in the monoclinic C2/c space group. It is characterized by negligible V3+/V4+ oxidation with the corresponding F-/O2- substitution and the presence of structural disordering. Using the Voronoi-Dirichlet partition (VDP) method, the Na+ and Li+ migration pathways in Tavorite-like NaVPO4F and closely related LiVPO4F (with the triclinic structure, P1[combining macron] S.G.) are analyzed. While the Na+ migration is suppressed in both cases, the Na+/Li+ ion exchange in NaVPO4F with the formation of monoclinic LiVPO4F could occur, but is difficult due to the sodium immobility rather than the instability of the lithium derivatives as was concluded from the DFT calculations.

Low-Temperature Reactions of α-Bromopropanoyl Chloride with Lithium Derivative of Ethyl Acetate

The reaction of 2-bromopropanoyl chloride with lithium ethyl acetate generated in situ by the reaction of equimolar amounts of lithium diisopropylamide with ethyl acetate forms, depending on the conditions (temperature, time, reagent ratio), diethyl 2,2′-(3-methyloxirane-2,2-diyl)diacetate, 2,2-dibromo-N,N-diisopropylpropanamide, and ethyl (5-methyl-4-oxo-4,5-dihydrofuran-2-yl)acetate as minor by-products along with the expected acylation product ethyl 4-bromo-3-oxopentanoate. The reaction with 2 or 5 equiv of lithium ethyl acetate (–78°C → –20°C) gave, together with the mentioned α-bromo ester, ethyl (5-methyl-4-oxo-4,5-dihydrofuran-2-yl)acetate formed as a result of transformations of the adduct of the second LiCH2CO2Et molecule and ethyl-4-bromo-3-oxopentanoate. The reaction 2-bromopropanoyl chloride with sodium malonic ester involves acylation of enol form of the primary expected acylation product to afford dimethyl |2-bromo-1-[(2-bromopropanoyl)oxy]propylidene-malonate.

Rubidium hydrazinidoborane: Synthesis, characterization and hydrogen release properties

In this work we present rubidium hydrazinidoborane RbN2H3BH3 (RbHB), the newest and last member of the alkali metal derivatives of hydrazine borane N2H4BH3 (HB). It is shown that HB readily reacts with metallic rubidium in THF at room temperature to form RbHB under argon atmosphere. The molecular and crystal structures of this new compound are discussed on the basis of FTIR spectroscopy, 11B MAS NMR spectroscopy, and powder X-ray diffraction analyses. RbHB crystallizes in a monoclinic P21 (No. 4) unit cell where each Rb+ cation adopts octahedral coordination surrounded by six [N2H3BH3]− anions, which are two more than for e.g. LiN2H3BH3 (with tetrahedral coordination) in accordance with the larger size of Rb+. RbHB is isostructural to potassium hydrazinidoborane KN2H3BH3. Its dehydrogenation properties, evaluated by using thermogravimetric analysis, differential scanning calorimetry, and isothermal analysis, are compared to those of the parent HB as well as to analogous compounds in order to evaluate the potential of RbHB as hydrogen storage material. According to the presented data, the dehydrogenation properties of RbHB are much better than those of HB and are comparable to those of the lithium derivative. Our main results are reported therein.

Unexpected Rearrangement of Dilithiated Isoindoline-1,3-diols into 3-Aminoindan-1-ones via N-Lithioaminoarylcarbenes: A Combined Synthetic and Computational Study.

The reaction of 2-aryl-3-hydroxyisoindolin-1-ones with the s-BuLi·TMEDA system in THF at -78 °C, affording a series of diastereomeric 3-aminoindan-1-ones via a novel rearrangement of the isoindolinone scaffold, is reported. It is proposed that α-elimination of LiOH from the transient N,O-dilithiated hemiaminal carbenoids leads to the formation of singlet carbenes followed by their trapping via an intramolecular C-H insertion. An alternative explanation based on an intramolecular Mannich reaction seem much less probable. A mechanistic-type study that combines spectroscopic data of the products and calculation results, with a special focus on the diverse lithiated intermediates that are most likely to engage in the title process (particularly those with internal Li bonds), is presented. The MP2 approach, including the NPA and QTAIM data, provided insight into structures and properties of all these species. Two reaction routes A and B appeared to be possible for the postulated carbene mechanism. An unusual metamorphosis of the CCN atom triad, from a near sp 1-azaallene-type in more stable noncarbene Li enolates to a roughly sp2 type in their carbene keto tautomers, is recognized in one of these pathways (route B). Dominant forms of resonance structures for the aforementioned tautomeric systems that have seven-membered quasi rings stabilized by Li+ ions bridging the N and carbonyl O atoms are indicated. Large computational difficulties arising from a huge impact of internal Li+ complexation on conformational preferences and electronic properties of carbonyl group-bearing lithium derivatives are also discussed. The new γ-keto carbene species under study belong to a subclass of acyclic aminoarylcarbenes.