Dilithium complexes of β-diketonates in acetonitrile solvent

Hiller, L.K.; Cockrell, John R.; Murray, Royce W.

doi:10.1016/0022-1902(69)80023-0

Cited by 7 publications

(3 citation statements)

References 6 publications

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“…26 The unsaturated aldehyde 8 is prone to polymerization, 28 particularly in the presence of Li metal and/or the Li enolate of DMA (2), 29 which may account for the appearance of polymer products following the reaction of Li metal with DMA under Ar (Figure 6). The products generated according to Scheme 1 are expected to be reactive, 30 moderately soluble 31 or gaseous, which is likely the reason that the reaction between neat DMA and Li metal proceeds to completion without the formation of a passivating SEI. In particular, the formation of the gaseous dimethylamine is confirmed by the analysis of gaseous products formed in symmetric Li/Li cells (Figure 1b).…”

Section: Resultsmentioning

confidence: 99%

Synergistic Effect of Oxygen and LiNO₃on the Interfacial Stability of Lithium Metal in a Li/O₂Battery

Giordani¹,

Walker²,

Bryantsev³

et al. 2013

J. Electrochem. Soc.

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Identification of electrolytes compatible with both electrodes of a nonaqueous Li/O2 battery is a considerable challenge. One solvent of interest, N,N-dimethylacetamide (DMA), has been shown to be stable toward the reactions of the air electrode, but decomposes rapidly when exposed to Li metal. Herein we investigate the electrochemical behavior of lithium metal electrodes in an electrolyte consisting of DMA and lithium nitrate, a combination that has been shown to have a dramatic effect on the cycle life of Li/O2 cells. Electrochemical impedance spectroscopy, in situ pressure analysis, mass spectrometry, scanning electron microscopy and theoretical calculations are used to study the electrode/solution interface. Remarkably efficient, long-term Li metal cycling in DMA is reported through the cooperative effect of dissolved oxygen and lithium nitrate.

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Section: Resultsmentioning

confidence: 99%

Synergistic Effect of Oxygen and LiNO₃on the Interfacial Stability of Lithium Metal in a Li/O₂Battery

Giordani¹,

Walker²,

Bryantsev³

et al. 2013

J. Electrochem. Soc.

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“…1 H or 13 C NMR data can supply information of the electron density on a specific proton or carbon atom in molecules. Hiller et al have reported that the 1 H NMR spectrum of the Li 2 (acac) + species exhibits signals at δ = 1.85 and 5.28 ppm versus TMS, signals which were assigned to the methyl and methine protons in acetylacetone, respectively. A sample of tetraethylammonium acetylacetonate in CH 3 CN exhibits methine resonance at 4.68 ppm, the upfield shift being consistent with the removal of the lithium cation field.…”

Section: Resultsmentioning

confidence: 99%

“…The formation of such a normal coordination-type species can be easily accepted by many chemists because of the possible stability on chelating in solution. The “dilithium complex” of a ligand anion (L - ), on the other hand, has still been regarded as an uncertain matter. Murray and Hiller first suggested involvement of two lithium ions in a ligand loss during one-electron reduction of Fe(acac) 3 in acetonitrile containing LiClO 4 as the supporting electrolyte: Similarly, the formation of [CH 3 COOLi 2 ] + species was suggested for the effect of LiClO 4 on the polarographic reduction of dimeric copper(II) acetate in acetonitrile .…”

Section: Introductionmentioning

confidence: 99%

UV−Visible and ¹H or ¹³C NMR Spectroscopic Studies on the Specific Interaction between Lithium Ions and the Anion from Tropolone or 4-Isopropyltropolone (Hinokitiol) and on the Formation of Protonated Tropolones in Acetonitrile or Other Solvents

et al. 2007

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The specific interaction between lithium ions and the tropolonate ion (C(7)H(5)O(2)-: L-) was examined by means of UV-visible and 1H or 13C NMR spectroscopy in acetonitrile and other solvents. On the basis of the electronic spectra, we can propose the formation of not only coordination-type species (Li+(L-)2) and the ion pair (Li+L-) but also a "triple cation" ((Li+)2L-) in acetonitrile and acetone; however, no "triple cation" was found in N,N-dimethylformamide (DMF) and in dimethylsulfoxide (DMSO), solvents of higher donicities and only ion pair formation between Li+ and L- in methanol of much higher donicity and acceptivity. The 1H NMR chemical shifts of the tropolonate ion with increasing Li+ concentration verified the formation of (Li+)2L- species in CD3CN and acetone-d6, but not in DMF-d6 or CD(3)OD. With increasing concentration of LiClO(4) in CD(3)CN, the 1H NMR signals of 4-isopropyltropolone (HL') in coexistence with an equivalent amount of Et(3)N shifted first toward higher and then toward lower magnetic-fields, which were explained by the formation of (Li+)(Et(3)NH+)L'- and by successive replacement of Et(3)NH+ with a second Li+ to give (Li+)2L'-. In CD(3)CN, the 1,2-C signal in the 13C NMR spectrum of tetrabutylammnium tropolonate (n-Bu(4)NC(7)H(5)O) appeared at an unexpectedly lower magnetic-field (184.4 ppm vs TMS) than that of tropolone (172.7 ppm), while other signals of the tropolonate showed normal shifts toward higher magnetic-fields upon deprotonation from tropolone. Nevertheless, with addition of LiClO(4) at higher concentrations, the higher and lower shifts of magnetic-fields for 1,2-C and other signals, respectively, supported the formation of the (Li+)2L- species, which can cause redissolution of LiL precipitates. All of the data with UV-visible and 1H and 13C NMR spectroscopy demonstrated that the protonated tropolone (or the dihydroxytropylium ion), H(2)L+, was produced by addition of trifluoromethanesulfonic or methanesulfonic acid to tropolone in acetonitrile. The order of the 5-C and 3,7-C signals in 13C NMR spectra of the tropolonate ions was altered by addition of less than an equivalent amount of H+ to the tropolonate ion in CD(3)CN. Theoretical calculations satisfied the experimental 13C NMR chemical shift values of L-, HL, and H(2)L+ in acetonitrile and were in accordance with the proposed reaction schemes.

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Solvent—solute interaction. Spectrophotometric and polarographic characteristic of copper—II. Acetylacetonate in organic solvents

Kalinowski

Gałazka

1980

Electrochimica Acta

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Dilithium complexes of β-diketonates in acetonitrile solvent

Cited by 7 publications

References 6 publications

Synergistic Effect of Oxygen and LiNO₃on the Interfacial Stability of Lithium Metal in a Li/O₂Battery

Synergistic Effect of Oxygen and LiNO₃on the Interfacial Stability of Lithium Metal in a Li/O₂Battery

UV−Visible and ¹H or ¹³C NMR Spectroscopic Studies on the Specific Interaction between Lithium Ions and the Anion from Tropolone or 4-Isopropyltropolone (Hinokitiol) and on the Formation of Protonated Tropolones in Acetonitrile or Other Solvents

Solvent—solute interaction. Spectrophotometric and polarographic characteristic of copper—II. Acetylacetonate in organic solvents

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Dilithium complexes of β-diketonates in acetonitrile solvent

Cited by 7 publications

References 6 publications

Synergistic Effect of Oxygen and LiNO3on the Interfacial Stability of Lithium Metal in a Li/O2Battery

Synergistic Effect of Oxygen and LiNO3on the Interfacial Stability of Lithium Metal in a Li/O2Battery

UV−Visible and 1H or 13C NMR Spectroscopic Studies on the Specific Interaction between Lithium Ions and the Anion from Tropolone or 4-Isopropyltropolone (Hinokitiol) and on the Formation of Protonated Tropolones in Acetonitrile or Other Solvents

Solvent—solute interaction. Spectrophotometric and polarographic characteristic of copper—II. Acetylacetonate in organic solvents

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Synergistic Effect of Oxygen and LiNO₃on the Interfacial Stability of Lithium Metal in a Li/O₂Battery

Synergistic Effect of Oxygen and LiNO₃on the Interfacial Stability of Lithium Metal in a Li/O₂Battery

UV−Visible and ¹H or ¹³C NMR Spectroscopic Studies on the Specific Interaction between Lithium Ions and the Anion from Tropolone or 4-Isopropyltropolone (Hinokitiol) and on the Formation of Protonated Tropolones in Acetonitrile or Other Solvents