Protonation Constants of Valin in Different Aqueous Solutions of Dimethylsulfoxide

Journal of Chemical Reactivity and Synthesis

دوره 12، شماره 2، شهریور 2022، صفحه 91-99   

نوع مقاله: Research Article

نویسندگان

Masumeh Jabbari^{* 1}؛ Ali Shamel²؛ Farrokh Ghari³

¹Chemistry Department, Islamic Azad University, Ardabil Branch, Ardabil, Iran,

²Chemistry Department, Islamic Azad University, Ardabil Branch, Ardabil, Iran

³Chemistry Department, Shahid Beheshti University, G. C., Tehran, Evin, Iran

چکیده

The protonation constants of valin (K1 and K2) was determined in binary mixtures of water with dimethylsulfoxide containing (0, 10, 20, 30, 40, and 50) % (v/v) using a combination of potentiometric method at 25 ^°C and constant ionic strength (0.1mol ·dm-3 sodium perchlorate). The protonation constants were analyzed using the normalized polarityparameter (ETN) and Kamlet, Abboud, and Taft (KAT) parameters. A very good linear correlation of log K versus the normalized polarity parameter was obtained. Dual-parameter correlation of log K versus π*(dipolarity/polarizability) and R (hydrogen-bond donor acidity) as well as π* and (hydrogen-bond acceptor basicity) also gives good results in various aqueous organic solvent mixtures. Finally, the results are discussed in terms of the effect of the solvent on the protonation constants.




 

کلیدواژه‌ها

Solvent Effect؛ Valine؛ Tautomeric؛ Dissociation Constant؛ Dimethylsulfoxide