%0 Generic
%A Dockter, David W.
%A Fanwick, Phillip E.
%A Kubiak, Clifford P.
%D 1996
%T Reactivity of Platinum−Oxygen Bonds: Kinetic and
Mechanistic Studies of the Carbonylation of Platinum Aryloxide
Complexes and the Formation of (Aryloxy)carbonyls
%U https://acs.figshare.com/articles/dataset/Reactivity_of_Platinum_Oxygen_Bonds_Kinetic_and_Mechanistic_Studies_of_the_Carbonylation_of_Platinum_Aryloxide_Complexes_and_the_Formation_of_Aryloxy_carbonyls/3657063
%R 10.1021/ja952680p.s001
%2 https://ndownloader.figshare.com/files/5746776
%K Complex 3 b
%K CO
%K aryloxide ligand exchange
%K carbon monoxide
%K Pt
%K NaOC 6 H 4
%K carbonylation
%K OMe
%K Platinum Aryloxide Complexes
%K NMR
%K aryloxy
%K complex
%X The reactions of [Pt(triphos)(Cl)][Cl]
(1) {triphos =
bis[2-(diphenylphosphino)ethyl]phenylphosphine}
with NaOC6H4-p-R, in the presence of
NaPF6, yields the aryloxy complexes
[Pt(triphos)(OC6H4-p-R)][PF6]
(R =
OMe (2a), Me (2b), H (2c), F
(2d), Cl (2e)). Upon reaction of
2a−e with carbon monoxide at pressures from
10
to 134 psi in acetonitrile the (aryloxy)carbonyl complexes
[Pt(triphos)(C(O)OC6H4-p-R)][PF6]
(3a−e) were obtained.
The molecular structure of
[Pt(triphos)(C(O)OC6H4-p-Me)][PF6]
(3b) was determined by X-ray diffraction.
Complex
3b crystallized in the monoclinic space group
P21/n (no. 14) with a =
10.797(1) Å , b = 19.927(3) Å, c
= 19.113(2)
Å, β = 98.07(1)°, V = 4071(2)
Å3, and Z = 4. The structure was solved
and refined to R = 0.035 and
Rw = 0.040
for 3958 reflections with I > 3σ(I).
The kinetics of the carbonylation of 2a−e
to form 3a−e were studied by
31P{1H} NMR. Rates of
carbonylation exhibit a first order dependence on [CO], but are
independent of the
concentration of free aryloxide in solution. Rates of aryloxide
ligand exchange were also found to be significantly
faster than rates of carbonylation. The rates of carbonylation
depend on the para-substituent of the aryloxy
ligand
and follow the order F (2d) > Me (2b) > OMe
(2a). These observations are interpreted in terms of a
carbonylation
mechanism that proceeds via a migratory insertion pathway, rather than
by nucleophilic attack at coordinated carbon
monoxide by free or dissociated aryloxide.
%I ACS Publications