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AcidBase Properties of Adenosine 5′‐Monophosphate, Guanosine 5′‐Monophosphate, and Inosine 5′‐Monophosphate in Aqueous Solutions of Methanol
Author(s) -
Gharib Farrokh,
Abbaszadeh Mehran,
Pousti Mohammad
Publication year - 2013
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.201200337
Subject(s) - chemistry , protonation , aqueous solution , ionic strength , guanosine , hydrogen bond , adenosine monophosphate , inorganic chemistry , organic chemistry , molecule , enzyme , ion , biochemistry
The protonation constants of adenosine 5′‐monophosphate, guanosine 5′‐monophosphate, and inosine 5′‐monophosphate were determined in binary mixtures of H 2 O containing 0, 10, 15, 20, 25, 30, 35, 40, 45, and 50% MeOH, using a combination of potentiometric and spectrophotometric methods at a constant temperature (25°) and constant ionic strength (0.1 mol⋅dm −3 NaClO 4 ). The protonation constants were analyzed using the normalized polarity parameter ( E $\rm{{_{T}^{N}}}$ ), and Kamlet, Abboud , and Taft ( KAT ) parameters. A linear correlation of log K vs. the normalized polarity parameter was obtained. Dual‐parameter correlation of log K vs. π * (dipolarity/polarizability) and α (H‐bond‐donor acidity), as well as π * and β (H‐bond‐acceptor basicity) also gives good results in various aqueous organic solvent mixtures. Finally, the results are discussed in terms of the effect of solvent on the protonation equilibria.