Tuning Reactivity of Platinum(II) Complexes

L
L
M
L
Y
X
k -2
k 2
L
Solvent
L
L
M
L
L
M
L
X
Y
X
Solv
11
-X
-X
L
L M Y
L
L
Y
L
M Solv
Scheme 2.2: A proposed dual reaction pathway for an associative substitution
mechanism at the Pt(II) centre.
Under pseudo first-order conditions, the concentration of the incoming nucleophile, Y, is
at least 10-fold excess than the metal complex in a 1:1 formation reaction. The k2 can be
determined by measuring the dependence of the observed rate constant, kobs, on the
initial concentration of the nucleophile [B]0, using Equation 2.12.
2.3.2 Activation Parameters
The reaction rates normally increase with the increase in temperature. The temperature
dependency is defined in terms of the rate constant and is useful in determining the
activation parameters of a given reaction. This is essential in assigning the mechanism of
that reaction. Once the experimental data has been obtained for the various terms that
contribute to the rate law, it is analysed using the Arrhenius equation) or by the
Transition-State Theory.
2.3.3 The Arrhenius Theory
The rigorous statement of the relationship between temperature and the rate constant,
k, was given by Arrhenius in 1889 26 as Equations 2.14 and 2.15: 26
L
fast