Research Article

Complex Formation Equilibria between Ag(I) and Thioureas in Propan-2-ol

Table 1

Stability constants ( as ) and standard free energy changes (as ) at different temperatures and , ionic strength self-determined by for the overall complexing reactions .

Ligand  K  K  K  K  K  K  K

Tu1 57.6 61.0 55.2 54.9 56.4 54.5 53.8
2 79.8 84.9 78.4 77 78.3 77 75.2
3 93.9 96.5 92.8 92.9 91.4 89.3 91.6

MeTu1 57.7 58.9 55.1 55 52.3 54.4 48.7
2 80.7 81.4 76.6 78.1 74.4 75.7 73.9
3 94.3 94.7 92.0 91.9 90 88.1 85.7

Me2Tu1 28.1 51.4 48.2 49.9 49.6 43.6 45.4
2 75.8 75.7 71.5 71.1 72.9 74.3 69.8
3 92.3 90.1 85.7 84.5 88.1 82.1 82.7

Me4Tu1 41.4 42.9 34.0 36.1 33.9 5.5 32.4
2 62.9 64.4 59.2 60.2 60.7 59.5 58.9
3 78.5 81.6 75.7 .85.4 71.7 71.5 72.6

EtTu1 56.4 58.9 53.3 54 53.7 53.1 57.3
2 80.9 80.8 78.4 77.3 76.9 76.2 77.7
3 97 96.8 92.2 91 90.9 91.2 91.8

Et2Tu1 61.2 60.8 53.5 53.4 53.1 53.1 50.5
2 83.1 84.1 77.5 77.4 77.5 78.4 76.4
3 100.2 101.3 94.5 92.9 93.4 94 91.1

EnTu1 69.7 68.9 68.9 62.9 62.5 65.3 63.4
2 89.3 90.8 89.3 87.1 86.4 84.4 85.6
3 110 105 98.4 98 96.1