Tuning Reactivity of Platinum(II) Complexes

List of Figures
Figure 4.1: Structures of the investigated dinuclear Pt(II) complexes. The numbering
scheme employed for pKa1 and pKa2, the NBO charges, bond length and bond angles for
the complexes is shown on the structure of 2,6pzn. ............................................................3
Figure 4.2: Density functional theoretical (DFT) minimum structures, HOMO and LUMO
frontier molecular orbitals for dinuclear Pt(II) complexes. .................................................... 11
Figure 4.3: (a) UV-Visible spectra for the titration of 0.1 mM 2,5pzn with NaOH as a
function of pH in the range 1 to 10 at I = 0.1 M (NaClO4) and T = 298.15 K; (b) Inset: the
titration curve at 297 nm. ................................................................................................... 13
Figure 4.4: Typical spectrum obtained from the stopped-flow (A) and UV-Vis
spectrophotometer (B) with double exponential fit for the reaction between 2,5pzn
(2.14 × 10 −5 M) and TU (1.00×10 −3 M) followed at 400 nm, I = 0.10M (0.01 M HClO4,
adjusted by NaClO4), T = 298.15 K. ..................................................................................... 18
Figure 4.5: Concentration dependence of kobs(1 st ) for the displacement of first aqua ligand
in 2,5pzn by thiourea nucleophiles, pH = 2.0, T = 298.15 K, I = 0.10 M (0.01 M HClO4,
adjusted with NaClO4). ........................................................................................................ 19
Figure 4.6: Concentration dependence of kobs(2 nd ) for the displacement of first aqua
ligand in 2,5pzn by thiourea nucleophiles, pH = 2.0, T = 298.15 K, I = 0.10 M (0.01 M
HClO4, adjusted with NaClO4). ............................................................................................ 19
Figure 4.7: Concentration dependence of kobs(3 rd ) for the displacement of first aqua
ligand in 2,5pzn by thiourea nucleophiles, pH = 2.0, T = 298.15 K, I = 0.10 M (0.01 M
HClO4, adjusted with NaClO4). ............................................................................................ 20
Figure 4.8:
1 H NMR spectra in D2O of the aromatic region of 0.022mM
[{cis-PtCl (NH3)2}2-µ-pzn] 2+ reaction with TU at 30°C showing the production of the major
degradation product free pyrazine (L) at δ 8.68 ppm and the starting complex (A) at δ = 9.04
ii