10.1021/ic202499u.s001
Guixiang Zeng
Guixiang
Zeng
Shigeyoshi Sakaki
Shigeyoshi
Sakaki
Theoretical Study on the
Transition-Metal Oxoboryl
Complex: M–BO Bonding Nature, Mechanism of the Formation Reaction,
and Prediction of a New Oxoboryl Complex
American Chemical Society
2012
BO
Rh
ligand
formation reaction
Gibbs
nature
interaction
MBrCl
Ir
Oxoboryl
oxoboryl
2012-04-16 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Theoretical_Study_on_the_Transition_Metal_Oxoboryl_Complex_M_BO_Bonding_Nature_Mechanism_of_the_Formation_Reaction_and_Prediction_of_a_New_Oxoboryl_Complex/2530840
The Pt–BO bonding nature and the formation reaction
of the
experimentally reported platinum(II) oxoboryl complex, simplified
to PtBr(BO)(PMe<sub>3</sub>)<sub>2</sub>, were theoretically investigated
with the density functional theory method. The BO<sup>–</sup> ligand was quantitatively demonstrated to have extremely strong
σ-donation but very weak d<sub>π</sub>-electron-accepting
abilities. Therefore, it exhibits a strong trans influence. The formation
reaction occurs through a four-center transition state, in which the
B<sup>δ+</sup>–Br<sup>δ−</sup> polarization
and the Br → Si and O p<sub>π</sub> → B p<sub>π</sub> charge-transfer interactions play key roles. The Gibbs
activation energy (Δ<i>G</i>°<sup>⧧</sup>) and Gibbs reaction energy (Δ<i>G</i>°) of
the formation reaction are 32.2 and −6.1 kcal/mol, respectively.
The electron-donating bulky phosphine ligand is found to be favorable
for lowering both Δ<i>G</i>°<sup>⧧</sup> and Δ<i>G</i>°. In addition, the metal effect
is examined with the nickel and palladium analogues and MBrCl[BBr(OSiMe<sub>3</sub>)](CO)(PR<sub>3</sub>)<sub>2</sub> (M = Ir and Rh). By a comparison
of the Δ<i>G</i>°<sup>⧧</sup> and Δ<i>G</i>° values, the M–BO (M = Ni, Pd, Ir, and Rh)
bonding nature, and the interaction energy between [MBrCl(CO)(PR<sub>3</sub>)<sub>2</sub>]<sup>+</sup> and BO<sup>–</sup> with
those of the platinum system, MBrCl(BO)(CO)(PR<sub>3</sub>)<sub>2</sub> (M = Ir and Rh) is predicted to be a good candidate for a stable
oxoboryl complex.