Prediction of the thermodynamic properties of aqueous metal complexes to 1000°C and 5 kb

Within the framework of a program aiming to improve the existing extractive recovery technology of fermentation products, the state of the art is critically reviewed. The acids under consideration are propionic, lactic, pyruvic, succinic, fumaric, maleic, malic, itaconic, tartaric, citric, and isocitric, all obtained by the aerobic fermentation of glucose via the glycolytic pathway and glyoxylate bypass. With no exception, it is the undissociated monomeric acid that is extracted into carbon-bonded and phosphorus-bonded oxygen donor extractants. In the organic phase, the acids are usually dimerized. The extractive transfer process obeys the Nernst law, and the measured partition coefficients range from about 0.003 for aliphatic hydrocarbons to about 2 to 3 for aliphatic alcohols and ketones to about 10 or more for organophosphates. Equally high distribution ratios are measured when long-chain tertiary amines are employed as extractants, forming bulky salts preferentially soluble in the organic phase.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/bit.22375

Extraction chemistry of fermentation product carboxylic acids

Reference LCIB-ARTICLE-2007-010doi:10.1021/cr030726oView record in Web of Science Record created on 2007-02-14, modified on 2017-05-12

Inorganic and bioinorganic solvent exchange mechanisms.

To obtain an indication of the tendencies of amino acids to leave water and enter a truly nonpolar condensed phase, distribution coefficients between dilute solution in water and dilute solution in wet cy- clohexane have been determined for each of the common amino acid side chains at pH 7; they are found to be closely related to the inside-outside distributions of the side chains observed in globular proteins. There was no evidence that excess water enters cyclohexane in association with these solutes. Cyclohexane-to-water distribution coefficients can be combined with vapor-to-water distribution coefficients reported earlier to yield vapor-to-cyclohexane distribution coefficients. Vapor-to-cyclohexane distribution coefficients provide an experimental index of susceptibility to attraction by dispersion forces, and the corresponding free energies are found to be linearly related to side-chain surface areas. Observations using different solvents and variously substituted side chains suggest that alcohols such as 1-octanol exert a specific attraction on the side chain of tryptophan. When less polar phases are used as a reference, leucine, isoleucine, valine, phenylalanine, and methionine are found to be more hydrophobic than tryptophan.

/pdf/comparing-the-polarities-of-the-amino-acids-side-chain-36uqortj1z.pdf

Comparing the polarities of the amino acids: side-chain distribution coefficients between the vapor phase, cyclohexane, 1-octanol, and neutral aqueous solution

Asymmetric hydrogenation of acetophenone with trans-RuH(η1-BH4)[(S)-tolbinap][(S,S)-dpen] (TolBINAP = 2,2‘-bis(di-4-tolylphosphino)-1,1‘-binaphthyl; DPEN = 1,2-diphenylethylenediamine) in 2-propanol gives (R)-phenylethanol in 82% ee. The reaction proceeds smoothly even at an atmospheric pressure of H2 at room temperature and is further accelerated by addition of an alkaline base or a strong organic base. Most importantly, the hydrogenation rate is initially increased to a great extent with an increase in base molarity but subsequently decreases. Without a base, the rate is independent of H2 pressure in the range of 1−16 atm, while in the presence of a base, the reaction is accelerated with increasing H2 pressure. The extent of enantioselection is unaffected by hydrogen pressure, the presence or absence of base, the kind of base and coexisting metallic or organic cations, the nature of the solvent, or the substrate concentrations. The reaction with H2/(CH3)2CHOH proceeds 50 times faster than that with D2/(...

Mechanism of Asymmetric hydrogenation of ketones catalyzed by BINAP/1,2-diamine-ruthenium(II) complexes

Use of ligand buffers for improved selectivity in the polarographic determination of metals Polarographic determination of zinc in the presence of a large amount of cadmium.

A convenient technique is described to determine reaction volumes by means of direct dilatometry. Reaction volumes were determined for the following complexation reactions: formation of monoamminenickel(II) in water (−0.1±0.5 cm3-mol−1); formation of the 1:1 nickel(II) complex with isoquinoline in methanol and ethanol (3.2±0.1 and 1.1±0.1 cm3-mol−1, respectively); formation of the 1:1 isothiocyanatoiron(III) complex in water, Me2SO, and DMF (8.9±0.2, 12.4±0.7, and 25.1±0.3 cm3-mol−1, respectively); formation of the 18-crown-6 potassium complex in water (10.9±0.2 cm3-mol−1). We discussed these values in terms of electrostriction and molecular size.

Dilatometric studies of reaction volumes for the formation of metal complexes in several solvents

The exchange rates of acetic acid coordinating to nickel(II) chloride, nickel(II) nitrate, and nickel(II) acetate in neat acetic acid and acetic acid/dichloromethane-d2 mixtures were measured by the oxygen-17 and proton NMR line-broadening methods. The activation parameters for the acetic acid exchange on these nickel(II) salts were independent of the concentration of acetic acid (HOAc) in the mixed solvents. The first-order rate constants at 25C and the activation parameters are k = (5.5 +/- 0.2) x 10V s , H = 41 +/- 2 kJ mol , and S = 3 +/- 7 J mol K for NiCl2, k = (3 +/- 1) x 10V s , H = 37 +/- 5 kJ mol , and element of = -18 +/- 20 J mol K for Ni(NO3)2, and k = (3 +/- 1) x 10V s , H = 50 +/- 5 kJ mol , and S = 28 +/- 20 J mol K for Ni(OAc)2. Solvent exchange was proposed to proceed via a dissociative-interchange mechanisms. 34 references, 5 figures, 1 table

Oxygen-17 and proton nuclear magnetic resonance studies on acetic acid exchange processes of the chloride, nitrate, and acetate of nickel(II) in acetic acid

Motoharu Tanaka

Papers

Use of ligand buffers for improved selectivity in the polarographic determination of metals Polarographic determination of zinc in the presence of a large amount of cadmium.

Dilatometric studies of reaction volumes for the formation of metal complexes in several solvents

Oxygen-17 and proton nuclear magnetic resonance studies on acetic acid exchange processes of the chloride, nitrate, and acetate of nickel(II) in acetic acid

Complex formation of copper(II) acetate with pyridine bases in anhydrous acetic acid

Metal complexes in acetic acid. Part 5. Proton magnetic resonance studies on acetic acid exchange at the first coordination sphere of manganese(II)