TY - JOUR
T1 - Reactions of pulsed-laser evaporated Ca, Sr, and Ba atoms with O2. Infrared spectra of the metal oxides, oxide dimers, dioxides, and peroxides in solid argon
AU - Andrews, Lester
AU - Yustein, Jason T.
AU - Thompson, Craig A.
AU - Hunt, Rodney D.
PY - 1994
Y1 - 1994
N2 - Pulsed-laser ablated Ca, Sr, and Ba atoms have been reacted with O2 in excess argon during condensation at 10 K. Infrared spectra and oxygen isotopic substitution show that the major products are the symmetrical OMO metal dioxide and the rhombic metal oxide dimer. The metal oxides and cyclic MO2 peroxides are minor products. In the case of calcium, activation energy provided by pulsed-laser ablation makes the reaction to give CaO, CaO2, (CaO)2, and OCaO possible. Strontium and barium are more reactive and the dioxides and peroxides increase on annealing the argon matrix to 25 K, which shows that no activation energy is necessary for the Sr and Ba atom reactions with O2. Photolysis decreased the peroxide in favor of the dioxide species. The alkaline earth metal peroxides are characterized by O-O stretching absorptions in the 700-cm-1 region and are distinctly different from the alkali metal superoxides, which are characterized by O-O stretching absorptions in the 1100-cm-1 region.
AB - Pulsed-laser ablated Ca, Sr, and Ba atoms have been reacted with O2 in excess argon during condensation at 10 K. Infrared spectra and oxygen isotopic substitution show that the major products are the symmetrical OMO metal dioxide and the rhombic metal oxide dimer. The metal oxides and cyclic MO2 peroxides are minor products. In the case of calcium, activation energy provided by pulsed-laser ablation makes the reaction to give CaO, CaO2, (CaO)2, and OCaO possible. Strontium and barium are more reactive and the dioxides and peroxides increase on annealing the argon matrix to 25 K, which shows that no activation energy is necessary for the Sr and Ba atom reactions with O2. Photolysis decreased the peroxide in favor of the dioxide species. The alkaline earth metal peroxides are characterized by O-O stretching absorptions in the 700-cm-1 region and are distinctly different from the alkali metal superoxides, which are characterized by O-O stretching absorptions in the 1100-cm-1 region.
UR - http://www.scopus.com/inward/record.url?scp=0347105031&partnerID=8YFLogxK
U2 - 10.1021/j100077a016
DO - 10.1021/j100077a016
M3 - Article
AN - SCOPUS:0347105031
SN - 0022-3654
VL - 98
SP - 6514
EP - 6521
JO - Journal of Physical Chemistry
JF - Journal of Physical Chemistry
IS - 26
ER -