Complexation of thallium(I) with adenosine 5'-monophosphate in aqueous methanol solutions.
The formation constants of the species formed in the systems H+ + thallium(I) + AMP and H+ + AMP have been determined in aqueous solutions of methanol at 25 degrees C and constant ionic strength 0.1 mol dm(-3) sodium perchlorate, using spectrophotometric and potentiometric techniques. Thallium(I) forms two mononuclear 1:1 complexes with AMP of the type TlHL and TlL- in the pH range of study (1-11), where L2- represents the fully dissociated ligand. The formation constants in various media were analyzed in terms of Kamlet and Taft's parameters. Single-parameter correlation of the formation constants, beta111, and beta101, versus alpha (hydrogen-bond donor acidity), beta (hydrogen-bond accepter basicity), and for pi* (dipolarity/polarizability) are relatively poor in all solutions, but multi-parameter correlation represents significant improvement with regard to the single-parameter models. Finally, the results are discussed in terms of the effect of the solvent on complexation.
Gharib
Farrokh
F
Chemistry Department, Shahid Beheshti University, Tehran, Evin, Iran. gharibf@hotmail.com
Kheradman
Tahereh
T
Amani
Parisa
P
D000249:Adenosine Monophosphate / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry*; D015394:Molecular Structure; D013793:Thallium / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D014867:Water; D000249:Adenosine Monophosphate; D013793:Thallium; D000432:Methanol