ic7b02563_si_001.pdf (545.56 kB)
Catalytic Performance of a Dicopper–Oxo Complex for Methane Hydroxylation
journal contribution
posted on 2017-12-16, 00:00 authored by Yuta Hori, Yoshihito Shiota, Tomokazu Tsuji, Masahito Kodera, Kazunari YoshizawaA dicopper(II) complex,
[Cu2(μ-OH)(6-hpa)]3+, where 6-hpa is 1,2-bis[2-[bis(2-pyridylmethyl)aminomethyl]-6-pyridyl]ethane,
generates an oxyl radical of CuIIO• and
catalyzes the selective hydroxylation of benzene to phenol. From the
structural similarity to methane activation catalysts (e.g., bare
CuO+ ion, Cu-ZSM-5, and particulate methane monooxygenase),
it is expected to catalyze methane hydroxylation. The catalytic performance
for the hydroxylation of methane to methanol by this dicopper complex
is investigated by using density functional theory (DFT) calculations.
The whole reaction of the methane conversion involves two steps without
radical species: (1) C–H bond dissociation of methane by the
CuIIO• moiety and (2) C–O bond
formation with methyl migration. In the first step, the activation
barrier is calculated to be 10.2 kcal/mol, which is low enough for
reactions taking place under normal conditions. The activation barrier
by the other CuIIO2• moiety
is higher than that by the CuIIO• moiety,
which should work to turn the next catalytic cycle. DFT calculations
show that the dicopper complex has a precondition to hydroxylate methane
to methanol. Experimental verification is required to look in detail
at the reactivity of this dicopper complex.