Solubilities of alkali metal chlorides in some amine and ether solvents

Abstract

Solubilities of alkali metal chlorides except lithium were determined in ammonia, EDA, methyl-and ethylamines, DME, and THF at three different temperatures. From these data, standard thermodynamic functions of solution and solvation with respect to ion formation were calculated. The standard free energies of solvation increased linearly as a function of D_1. However, the requirements of the Bom equation were not satisfied because the slopes and intercepts of these plots were not equal. Values of the entropies of solvation are roughly accounted for on the basis of the freezing out of a fixed number of solvent molecules. The superiority of ammonia as an agent for solvating ions is attributed to its relatively low molecular entropy compared to other solvents. A criterion for salt-like behavior is introduced and used to suggest that saturated alkali metal solutions are salt like and are probably dominated by the +• ~ion pairs. On this basis solubilities of metals in ammonia are too large to be accounted for without introducing additional species.

Lithium Ion Solvation: Amine and Unsaturated Hydrocarbon Solvates of Lithium Hexamethyldisilazide (LiHMDS)

“…In contrast, the solvation numbers for LiHMDS dimers and monomers are insensitive to solvent structure. Therefore, the solvent dependence on Δ G ° agg stems from variable internal entropies associated with packing ligands into sterically congested coordination spheres. ,, The LiHMDS−ether solvates afforded a similar conclusion …”

Evidence for Reversible Ylide Formation: Equilibrium between Free Alkylidenecarbenes and Ethereal Solvent−Alkylidenecarbene Complexes (Oxonium Ylides)

“…The temperature dependence of the product profiles described above (that decreasing temperature has a tendency to decrease the yield of the free alkylidenecarbene-derived products, i.e., cyclopentenes, alkynes, and vinylammonium salts and increase that of the vinyloxonium ylide-derived products, vinyl ethers) might be attributed to a rapid equilibrium between the free alkylidenecarbene 1 and the oxonium ylide 2 . , Based on the assumption that the process leading to the formation of the oxonium ylide 2 from the alkylidenecarbene 1 and THF is associated with a decrease in entropy, decreasing the reaction temperature can reasonably be expected to yield a higher concentration of the oxonium ylide 2 , which, in turn, increases the relative amount of the three-component coupling products, as was indeed observed. The reaction pathways of Scheme suggest that the concentration of amines has some influence on the yield of vinylammonium salts and vinyl ethers; the yield of vinylammonium salts will depend upon the concentration of amines used and will increase with the higher concentrations of amines, as shown in Table .

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High-Performance Pd3Pb Intermetallic Catalyst for Electrochemical Oxygen Reduction

“…The formation of Pd 3 Pb nanoparticles in a THF solution is shown in the following equations For the two reactions above, either KCl or LiCl is produced as a byproduct. Since KCl is not soluble in THF, reduction using the KEt 3 BH results in an insoluble KCl matrix that can trap as-produced Pd 3 Pb particles, preventing their agglomeration during synthesis as well as during annealing. The experimental details are presented in Supporting Information (SI).…”

“…For the two reactions above, either KCl or LiCl is produced as a byproduct. Since KCl is not soluble in THF, 29 We further study the effect of annealing conditions (annealing temperature and annealing time) on the ordering and particle sizes of Pd 3 Pb phases. When hydride was used as reducing agent, stable hydride phase (PdH 0.5 ) may be formed during the initial reduction reaction, which may impede the formation of homogeneous alloy or ordered intermetallic phases…”