REACTIONS OF LASER ABLATED BE ATOMS WITH $O_{2}$: INFRARED SPECTRA OF BERYLLIUM OXIDES IN SOLID ARGON
Loading...
Date
1994
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
Pulsed-laser ablated beryllium atoms codeposited with $O_{2}$ in excess argon at 10K yielded new beryllium-oxygen molecules. The initial reaction to make BeO is endothermic, but activation energy is provided by hyperthermal Be atoms. A strong band at $1572.9 cm^{-1}$ and weak hand at $396.9 cm^{-1}$ gave oxygen isotopic shifts consistent with a BeO diatomic molecule end are assigned to the $O_{2}-BeO$ complex analogous to the Ar-BeO complex. A sharp band at $1413.2 cm^{-1}$ exhibited an oxygen isotopic triplet with $^{16,18}O_{2}$ and shifts appropriate for linear OBeO. A nearly coincident band at $1412.4 cm^{-1}$ gave an isotopic doublet and shifted in agreement with linear BeOBe. Quantum chemical calculations at the MBPT[2] level predict $^{3}\Sigma$ ground stated and $\nu_{3}$ fundamentals at 1422.5 and $1418.2 cm^{-1}$ for OBeO and BeOBe, respectively, in excellent agreement with the observed values. Three bands at 1131.2, 866.3, and 522.4 $cm^{-1}$ increased together on photolysis, yielded isotopic triplets, and agreed with MBPT[2] calculations for rhombic $Be_{2}O_{2}$. A sharp photosensitive band at 988.6 $cm^{-1}$ gave oxygen isotopic shifts consistent with another linear OBeO species and is tentatively assigned to the molecular anion. An intense band at 1$465.1 cm^{-1}$ that appeared on annealing gave oxygen isotopic shifts in agreement with calculations for linear BeOBeO. Two hands at 1288.9 and $1264.1 cm^{-1}$ appeared on photolysis end gave isotopic triplets und shifts that are in excel lent agreement with calculations for branched $BeBeO_{2}$. Annealing produced bands at 871.8 and $436.1 cm^{-1}$ that decreased on photolysis and are assigned to $BeO_{3}$.
Description
Author Institution: Department of Chemistry, University of Virginia