Studies in the tetraarylborates

Vandkberg, John T.; Moore, Carl R.; Cassaretto, Frank P.; Posvic, Harvey

doi:10.1016/s0003-2670(01)81750-5

Cited by 28 publications

(2 citation statements)

References 2 publications

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“…83,84 The [B(Ar F ) 4 ] À anions with Ar F = C 6 H 4 F, C 6 F 5 , 4-CF 3 C 6 H 4 and 3,5-(CF 3 ) 2 C 6 H 3 , (Fig. 8) are readily made as sodium salts by reaction of Na[BF 4 ] with the appropriate Grignard reagent BrMg(Ar F ), [85][86][87] and can be converted to [NR 4 ] + salts by metathesis with [NR 4 ]I in CH 2 Cl 2 . 88 Various [B(Ar F ) 4 ] À salts are commercially available, although very expensive, but we have found that, depending on the metal reagents used, it is often possible to recover the electrolyte after deposition, re-purify it and hence recycle it.…”

Section: New Electrolytesmentioning

confidence: 99%

Electrodeposition from supercritical fluids

Bartlett

Cook

George

et al. 2014

Phys. Chem. Chem. Phys.

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Recent studies have shown that it is possible to electrodeposit a range of materials, such as Cu, Ag and Ge, from various supercritical fluids, including hydrofluorocarbons and mixtures of CO2 with suitable co-solvents. In this perspective we discuss the relatively new field of electrodeposition from supercritical fluids. The perspective focuses on some of the underlying physical chemistry and covers both practical and scientific aspects of electrodeposition from supercritical fluids. We also discuss possible applications for supercritical fluid electrodeposition and suggest some key developments that are required to take the field to the next stage.

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Section: New Electrolytesmentioning

confidence: 99%

Electrodeposition from supercritical fluids

Bartlett

Cook

George

et al. 2014

Phys. Chem. Chem. Phys.

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“…The four BARF anions were prepared as alkali metal salts by literature methods or minor modification thereof [6][7][8] and converted into tetraalkylammonium salts by metathesis with the corresponding [NR 4 ]I in CH 2 Cl 2 solution, followed by recrystallisation from diethyl ether. Representative examples are described.…”

Section: Synthesis Of Barf Saltsmentioning

confidence: 99%

Phase behaviour and conductivity study on multi-component mixtures for electrodeposition in supercritical fluids

Bartlett

Cook

George

et al. 2010

Phys. Chem. Chem. Phys.

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Electrochemistry in supercritical CO(2) (scCO(2)) is difficult because the very low dielectric constant of the fluid restricts the solubility of ionic species and the conductivity of dissolved electrolytes. To overcome this problem to allow us to carry out electrodeposition at macroelectrodes from scCO(2) we have investigated the use of co-solvents and modified electrolyte salts chosen to increase their solubility and dissociation in the supercritical fluid. Here we report results of phase behaviour studies for mixtures of CO(2) with [NBu(n)(4)][BF(4)] and either methanol (CH(3)OH) or acetonitrile (CH(3)CN) as the co-solvent. These show that the solubility of [NBu(n)(4)][BF(4)] is approximately 5 times larger when CH(3)CN is the co-solvent rather than CH(3)OH. Consequently the phase behaviour of the ternary of CO(2)-[NBu(n)(4)][BF(4)]-CH(3)CN was studied in greater detail over a range of compositions. To enhance the conductivity of scCO(2)-CH(3)CN a range of electrolyte salts was synthesised in which the [NBu(n)(4)](+) and/or [BF(4)](-) ion were replaced by different derivatives. Results for the phase behaviour and conductivity of these modified electrolyte salts in scCO(2)-CH(3)CN are reported for several different compositions. We find that increasing the degree of fluorination and size of the ions increases the solubility of the electrolyte salt in scCO(2)-CH(3)CN. Of the 11 electrolytes investigated [NBu(n)(4)][B{3,5-C(6)H(3)(CF(3))(2)}(4)] appears the most suitable for use in scCO(2)-CH(3)CN with a molar conductivity of 22-26 S cm(2) mol(-1) and a maximum measured conductivity of approximately 3 mS cm(-1) for 0.07 M [NBu(n)(4)][B{3,5-C(6)H(3)(CF(3))(2)}(4)] dissolved in scCO(2)-CH(3)CN (molar ratio CH(3)CN : CO(2) approximately 0.12) at 20 MPa and 328.15 K. This is an order of magnitude improvement over similar results for the [NBu(n)(4)][BF(4)] parent. Studies of the conductance as a function of the electrolyte concentration suggest that triple ions make an important contribution to the conductivity of the supercritical fluid.

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Designing Ionic Liquids: 1‐Butyl‐3‐Methylimidazolium Cations with Substituted Tetraphenylborate Counterions

et al. 2003

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The hydrophobic, low melting, 1‐butyl‐3‐methylimidazolium (BMIm) salts [BMIm][BPh4] (1), [BMIm][B(C6H4Me‐4)4] (2), [BMIm][B{C6H4(CF3)‐4}4] (3), [BMIm][B{C6H3(CF3)2‐3,5}4] (4), [BMIm][B{C6H4(C6F13)‐4}4] (5), [BMIm][B{C6H4(SiMe3)‐4}4] (6), [BMIm][B(C6H4{SiMe2(CH2CH2CF3)}‐4)4] (7), [BMIm][B{C6H4(SiMe2C8H17}‐4}4] (8) and [BMIm][B(C6H4{SiMe2(CH2CH2C6F13)}‐4)4] (9) have been prepared. Systematic variation of the substituents on the tetraphenylborate anion allowed an assessment of their influence on the physical properties of the imidazolium salts. Structural investigations using NMR and IR spectroscopy, combined with single crystal X‐ray structure determinations for 2, 3, 5 and 6, revealed hydrogen‐bonding interactions between the imidazolium ring protons and the borate anion, both in the solid state and in solution. These interactions are weakened upon the introduction of electron‐withdrawing substituents in the anion and follow the order 3,5‐(CF3)2 < −C6F13 < −CF3 < −SiMe2CH2CH2C6F13 < −SiMe2CH2CH2CF3 < −H < −Me < −SiMe3. The melting points of the salts depend primarily on the bulk of the lipophilic substituents, and decrease with increasing size. Bulky lipophilic substituents dramatically enhance the solubility of the imidazolium borates 8 and 9 in hexane and reduce their relative polarity. These unique properties make imidazolium borates 8 and 9 interesting as amphiphilic ionic liquids with low polarity. Attempts to crystallise 7 resulted in decomposition. A single‐crystal X‐ray structure determination of the product, isolated in 6% yield, showed that a carbene−tris[4‐{dimethyl(3,3,3‐trifluoropropyl)silyl}phenyl]borane adduct was formed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

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Studies in the tetraarylborates

Cited by 28 publications

References 2 publications

Electrodeposition from supercritical fluids

Electrodeposition from supercritical fluids

Phase behaviour and conductivity study on multi-component mixtures for electrodeposition in supercritical fluids

Designing Ionic Liquids: 1‐Butyl‐3‐Methylimidazolium Cations with Substituted Tetraphenylborate Counterions

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