Tuning Reactivity of Platinum(II) Complexes

Figure 7.1 Density Functional theoretical (DFT) minimum energy structures,
HOMO and LUMO frontier molecular orbitals for investigated
diaqua Pt(II) complexes …………………………………................................12
Figure 7.2 HOMO-LUMO Energy gap as a function of number of carbons for
the diaqua complexes……………………........................................................13
Figure 7.3 UV-Vis spectra of the diaqua OctPt complex recorded as a
function of pH in the range of 2-10; I = 0.10 M (NaClO4), T = 25 ºC.
Inset: Plot of absorbance vs. pH at 241 nm…....................................... 14
Figure 7.4 An array of 1H NMR spectra of HexPt-Cl (showing methylene
(CH2) protons only) acquired during the reaction with 6 equiv. TU
in D2O, at 30 °C ………………………………………………………………………17
Figure 7.5 195 Pt NMR spectra of mixtures HexPt-Cl and TU (1:2; 1:4 and 1:6
equiv.) in D2O, at 30 °C……………………………………………..……………19
Figure 7.6 Typical kinetic traces for two step reaction between OctPt (0.1
mM) and TU (3 mM) recorded at 363 nm, T =298K , pH = 2.0……21
Figure 7.7 Concentration dependence of kobs(1 st ), s -1 , for the simultaneous
displacement of the coordinated water molecules in OctPt by
thiourea nucleophiles, pH =2.0, T =298 K………………………………. 21
Figure 7.8 Concentration dependence of kobs(2 nd ), for the displacement of the
ammine ligand in OctPt by thiourea nucleophiles, pH =2.0, T =298
K…………………………………………………………………………………………... 22
Figure 7.9 Eyring plots for the determination of the activation enthalpies and
entropies for k2, 1st of all nucleophiles studied with OctPt
complex …………………………………………………............................... 24
Figure 7.10 Eyring plots for the determination of the activation enthalpies and
entropies for k2(2 nd ) of all nucleophiles studied with OctPt
complex …………………………………………………………………………………25
xvi