Interaction of Thallium (I) with Cytidine 5
-Monophosphate in Different Ionic Strengths and Various Media

The formation constants of the species formed in the systems H+ + cytidine 5
-monophosphate (CMP)and H+ + cytidine 5
-monophosphate + Tl (I) ion have been determined in aqueous solution in a widepH range of 1.5 to 10.5 at 25 °C and different ionic strengths ranging from 0.1 to 1.5 moldm-3NaClO4, NaNO3, and NaCl using potentiometric-spectrophotometric technique. The composition ofthe complexes was specified and was shown that thallium ion forms mononuclear two 1:1 complexeswith CMP. The general trend for the protonation constants of CMP and its complexes with thallium(I) are in the order of NaClO4> NaNO3> NaCl in different ionic media. The dependence of formationconstants on ionic strength are described by a Debye-Huckel type equation and interpreted for thevarious supporting electrolytes.