Medium Effects on Deprotonation of Mono- and Di-protonated Piperazines in Binary Aqueous Mixtures of some Protic, Aprotic and Dipolar Aprotic Cosolvents

Solubility and solvation thermodynamics of dl-nor-valine in aqueous solutions of NaCl and KCl

“…For quite a long time, several studies on the solubilities of different amino acids have been carried out in water, in mixed solvents and in both with or without salts using several chemical and thermodynamic models under different experimental conditions [2][3][4][5][6][7]. It has been observed that experimental temperature [2,4], polarity of the solvents [8][9][10], ionic strength [3,11], acidity or alkalinity of the media [4,6,9,12], etc., affect the solubility of amino acids and hence the thermodynamics of solvation significantly. The variation of amino acid solubility with the temperature was explained precisely by using different standard equations and models where the theoretical results were justified with the experimental observations [2,[13][14][15][16].…”

Solubility and Solvation Thermodynamics of a Series of Homologous α-Amino Acids in Nonaqueous Binary Mixtures of Ethylene Glycol and Dimethyl Sulfoxide

“…In all these three cases this phenomenon arises because of decreased H-bonding, and acid–base, solvophobic, and solvophilic interactions with the increased concentration of dipolar aprotic cosolvents. The order of size of cosolvents is 0.498 nm (DMF) > 0.491 nm (DMSO) > 0.412 nm (ACN) …”

“…The order of size of cosolvents is 0.498 nm (DMF) 27 > 0.491 nm (DMSO) 36 > 0.412 nm (ACN). 28 All the three dipolar aprotic cosolvents may participate in self-association (i.e., dimerization, Schemes 3, 38 4a 17 , and 4b 16,29 ) at a higher concentration.…”

“…Dimethyl sulfoxide (DMSO) 28 (> 99.8 %, Sigma-Aldrich) was first dried over fused CaCl 2 for 3 to 4 days, decanted, and then distilled under reduced pressure. The distilled sample was preserved in a well stoppered Jena bottle in desiccators and redistilled before use.…”

Solubility and Chemical Thermodynamics of d,l-Alanine and d,l-Serine in Aqueous NaCl and KCl Solutions

“…For aqueous electrolyte solutions containing amino acids, experimental works for a long time have been most focused on the study of the electrolyte effect on the solubility of different amino acids. − The different factors such as chemical structure, the polarity of the solvents, ionic strength, acidity or alkalinity of the media, , experimental temperatures, and the concentration of the electrolyte present in aqueous amino acid solution can affect the solubility of the biomolecular species and hence the thermodynamics of solvation significantly. Earlier studies , have shown that the solubility as well as the thermodynamics of solvation of these molecules determines their biochemical and biophysical mode of actions.…”