The complexation reactions of N-methylated polyamines with silver(I) in dimethylsulfoxide

The thermodynamic parameters for the complex formation reactions in dimethy lsulfoxide (dmso) between Ag(I) and the following polyamines: N,N ' -dimeth ylethylenediamine (dmen), N,N,N ' ,N ' -tetramethylethylenediamine (tmen), N,N " -dimethyldiethylenetriamine (dmdien) and N,N,N ' ,N ", N " -pentameth yldiethylenetriamine (pmdien) have been determined by potentiometric and ca lorimetric techniques at 298 K and 0.1 mol dm(-3) ionic strength (NEt4ClO4) Only mononuclear complexes are formed (AgLj+ j = 1, 2) where the ligands a ct prevalently as chelate agents. All the complexes are enthalpy stabilized whereas the entropy changes counteract the complex formation. The results are discussed in terms of different basicities and steric requirements of b oth the ligands and the complexes formed.