Oxidation of ligand-protected aluminum clusters: an ab-initio molecular dynamics study
MetadataShow full item record
We report Car-Parrinello molecular dynamics simulations of the oxidation of ligand-protected alu-minum clusters that form a prototypical cluster-assembled material. These clusters contain a smallaluminum core surrounded by a monolayer of organic ligand. The aromatic cyclopentadienyl ligandsform a strong bond with surface Al atoms, giving rise to an organometallic cluster that crystallizesinto a low-symmetry solid and is briefly stable in air before oxidizing. Our calculations of isolatedaluminum/cyclopentadienyl clusters reacting with oxygen show minimal reaction between the ligandand O2molecules at simulation temperatures of 500 and 1000 K. In all cases, the reaction pathwayinvolves O2diffusing through the ligand barrier, splitting into atomic oxygen upon contact with thealuminum, and forming an oxide cluster with aluminum/ligand bonds still largely intact. Loss of in-dividual aluminum-ligand units, as expected from unimolecular decomposition calculations, is notobserved except following significant oxidation. These calculations highlight the role of the ligandin providing a steric barrier against oxidizers and in maintaining the large aluminum surface area ofthe solid-state cluster material.
The article of record as published may be found at http://dx.doi.org/10.1063/1.4867467
RightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
Showing items related by title, author, creator and subject.
Activation of C−H, N−H, and O−H Bonds via Proton-Coupled Electron Transfer to a Mn(III) Complex of Redox-Noninnocent Octaazacyclotetradecadiene, a Catenated-Nitrogen Macrocyclic Ligand Vaddypally, Shivaiah; Warren Tomlinson; Owen T. O’Sullivan; Ran Ding; Megan M. Van Vliet; Bradford B. Wayland; Joseph P. Hooper; Zdilla, Michael J. (ACS Publications, 2019);Reaction of 1,3-diazidopropane with an electron-rich Mn(II) precursor results in oxidation of the metal center to a Mn complex with concomitant assembly of the macrocyclic ligand into the 1,2,3,4,8,9,10,11-octaazacyclote ...
Alnemrat, Sufian; Hooper, Joseph P. (2014);We report Car-Parrinello molecular dynamics simulations of the oxidation of aluminum-cyclopentadienyl clusters currently being considered as novel fuels or energetic materials. These clusters contain a small aluminum ...
Alnemrat, S.; Hooper, J.P. (2014);Car-Parrinello molecular dynamics combined with a metadynamics algorithm is used to study the initial interaction of O 2 with the low-valence organoaluminum clusters Al 4 Cp 4 (Cp = C 5 H 5 )and Al 4 Cp ∗ 4 (Cp ∗ = C5[CH3]5). ...