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E–H (E = N and P) Bond Activation of PhEH2 by a Trinuclear Yttrium Methylidene Complex: Theoretical Insights into Mechanism and Multimetal Cooperation Behavior
journal contribution
posted on 2017-08-16, 13:29 authored by Gen Luo, Yi Luo, Zhaomin HouE–H (E = N and P) bond activation
of PhEH2 by
a trinuclear yttrium methylidene complex to give a μ3-EPh species has been investigated through DFT calculations. It has
been revealed that the reaction involves three major steps, i.e.,
activation of one of the two E–H bonds, intramolecular isomerization,
and the subsequent activation of the second E–H bond. The first
E–H bond activation is a mono-metal-assisted σ-bond metathesis
(σ-BM) process, while the second E–H bond activation
is achieved by the cooperation of three metal sites. The effect of
the phenyl group in PhEH2 has also been examined. It has
been found that the phenyl group in PhNH2 showed a significant
steric effect for the N–H activation, but in the case of PhPH2, such steric effect was not observed. The relatively low
energy barriers and significant exergonic feature lead us to predict
that the trinuclear yttrium methylidene complex should be also effective
for activation of NH3 and PH3. In addition,
a general behavior of the activation of CX (X = O and S) and
E–H (E = C, N, and P) bonds by multialkyl-bridged trinuclear
rare-earth complexes has been described, which could be beneficial
for further studies on the chemical transformations at multimetallic
frameworks.