3 research outputs found
Aqueous Chemistry of the Metallocene [Cp<sub>2</sub>MoCl<sub>2</sub>]BF<sub>4</sub>: Evidence of Autocatalytic Molybdenum(V) Reduction in Water
The
aqueous chemistry of the air-stable MoÂ(V) metallocene [Cp<sub>2</sub>MoCl<sub>2</sub>]ÂBF<sub>4</sub> (<b>1</b>) yields an
unexpected autocatalytic reduction when water is added to an acetonitrile
solution of <b>1</b>. While <b>1</b> yields the expected
stable Cp–Mo ligation and rapid chloride hydrolysis in water,
a MoÂ(V) → MoÂ(IV) reduction to the metallocene Cp<sub>2</sub>MoCl<sub>2</sub> (<b>2</b>) was evident. Under acidic conditions
(pH ∼2) or trace amounts of water this reduction was slow enough
to be monitored spectroscopically, and it is shown to be autocatalytic
in aqueous <b>2</b>. No reaction occurs when <b>1</b> and <b>2</b> are in the dichloride form in acetonitrile (i.e., no water).
It is hypothesized that the added water serves two roles. First it
initially reduces a small population of <b>1</b> to <b>2</b>, and then as the aquated MoÂ(IV) metallocene, it catalyzes the reduction
of the remaining MoÂ(V) in water. This is the first aqueous investigation
of the MoÂ(V) metallocene, and it shows a novel and unprecedented autocatalytic
reduction that is mediated by water
Phosphonothioate Hydrolysis Turnover by Cp<sub>2</sub>MoCl<sub>2</sub> and Silver Nanoparticles
The metallocene bisÂ(cyclopentadienyl)ÂmolybdenumÂ(IV) dichloride
(Cp<sub>2</sub>MoCl<sub>2</sub>; Cp = η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>) is the first organometallic compound to promote the
hydrolysis of phosphonothioates with selective P–S scission
in a stoichiometric fashion. This report shows that silver nanoparticles
capped with borohydride ions promote turnover in this hydrolytic process,
as indicated by <sup>31</sup>P NMR studies on the reaction of <i>O</i>,<i>S</i>-diethyl phenylphosphonothioate (DEPP)
with Cp<sub>2</sub>MoCl<sub>2</sub> (pH 7). This is the first example
of the joint use of nanoparticles and molybdenum metallocenes to promote
phosphonothioate hydrolysis. Initial results indicate the turnover
may be due to free Ag<sup>+</sup>(aq) ions present in the solution
that arise either from the slow dissolution of the nanoparticles or
from interactions with the Ag nanoparticle surface
Phosphonothioate Hydrolysis Turnover by Cp<sub>2</sub>MoCl<sub>2</sub> and Silver Nanoparticles
The metallocene bisÂ(cyclopentadienyl)ÂmolybdenumÂ(IV) dichloride
(Cp<sub>2</sub>MoCl<sub>2</sub>; Cp = η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>) is the first organometallic compound to promote the
hydrolysis of phosphonothioates with selective P–S scission
in a stoichiometric fashion. This report shows that silver nanoparticles
capped with borohydride ions promote turnover in this hydrolytic process,
as indicated by <sup>31</sup>P NMR studies on the reaction of <i>O</i>,<i>S</i>-diethyl phenylphosphonothioate (DEPP)
with Cp<sub>2</sub>MoCl<sub>2</sub> (pH 7). This is the first example
of the joint use of nanoparticles and molybdenum metallocenes to promote
phosphonothioate hydrolysis. Initial results indicate the turnover
may be due to free Ag<sup>+</sup>(aq) ions present in the solution
that arise either from the slow dissolution of the nanoparticles or
from interactions with the Ag nanoparticle surface