Nkabinde, Slindokuhle, V.Kinunda, GraceJaganyi, Deogratius2018-09-192018-09-192017SV Nkabinde, G Kinunda, D Jaganyi - Inorganica Chimica Acta, 2017 - Elsevierhttp://hdl.handle.net/20.500.11810/4915The substitution kinetics of the complexes [Pt(II)(bis(2-pyridylmethyl)amine)H2O](ClO4)2, Ptdpa and [Pt(II)(bis(2-pyridylmethyl)sulfide)H2O](ClO4)2, Ptdps, with a series of azole nucleophiles: Imidazole (Im), 1-methylimidazole (MIm), 1,2-Dimethylimidazole (DIm), 1,2,4-triazole (Trz) and pyrazole (Pyz), were studied in an aqueous medium at constant ionic strength (0.1 M NaClO4). The substitution of the coordinated water ligand on the Pt(II) complexes by the azoles was studied under pseudo-first order conditions as a function of the incoming nucleophiles concentration and temperature using either stopped-flow techniques or UV-Vis spectroscopy. Ptdps was found to be more reactive (three magnitude higher) than Ptdpa. The second-order rate constant, k2, for all the nucleophiles ranged between 0.087 ± 0.005 and 0.926 ± 0.05 M−1 s−1 for Ptdpa and between 146 ± 4 and 1458 ± 10 M−1 s−1 for Ptdps. The rate of substitution of the aqua ligand is dependent on the strength of the σ-donor character and the π-acceptability of the trans atom to the leaving group. The observed reactivity trend for the azoles followed the trend, MIm > Im > DIm > Trz > Pyz. This reactivity trend correlates with the basicity, steric and electrophilic effects of the nucleophiles. The X-ray crystal structure of Ptdps–Cl is reported.enPlatinum(II)SubstitutionKineticsAzolesJournal Article, Peer Reviewedhttp://dx.doi.org/10.1016/j.ica.2017.05.054.