The CO stretch frequency of fully CO covered Ag-clusters in dependence on cluster size

Abstract

Silver clusters Ag L prepared either by the gas aggregation technique (GAT) or by matrix aggregation of Ag were embedded in CO and CO/Ar-matrices. The vibrational CO stretch frequency at the monolayer coverage, which is found on bulk silver at 2110 cm\, preserves its value with decreasing particle size, Ag L n5300. For smaller clusters a decrease of this frequency with decreasing size was observed. For the smallest investigated clusters Ag L , n:30, a value of 2080 cm\ was obtained. The weakening of the CO bond is an indication of a charge transfer from the cluster to the CO monolayer. This result is in accordance with the surface plasmon absorption measurements of Ag-clusters isolated in CO matrices.

Laboratory Studies on the Formation of Formic Acid (Hcooh) in Interstellar and Cometary Ices

“…We can see a very small absorption at 1984 cm −1 in the irradiated D 2 O/CO ice samples, presumably since the relative abundance of CO may be higher than the H 2 O/CO ice samples within the margin of error bars described in Section 2. In addition, we tentatively assign the carrier of the band at 2114 cm −1 to carbon monoxide which is surface bound to the silver surface, as has been previously reported (Froben et al 1996;Jamieson et al 2006).…”

Mechanistical studies on the formation of carbon dioxide in extraterrestrial carbon monoxide ice analog samples

“…Due to the low natural abundance of the 17 O isotope of molecular oxygen (0.038%), the band occurring at 2111 cm À1 had previously been assigned to an interaction of carbon monoxide with the silver surface 24 in accordance with the experimental work of ref. 33, rather than from the C 17 O fundamental which also absorbs at this position (2112 cm À1 ). 31 However, if this is the case, considering the relative concentrations of carbon monoxide isotopomers in our sample, we would expect to see additional, stronger peaks from the Ag- 13 CO and Ag-C 18 O counterparts and possibly Ag-13 C 18 O.…”

Density functional study of CO binding on small AgnPdm clusters

“…Anionic Ag n CO À clusters can not be observed in the experiments [14,15]. Neutral Ag n (CO) m complexes are only detected in the presence of excessive CO such as in the CO droplet [16,17]. Ag 2 was found not to react with CO [18], while Ag 3 CO and Ag 4 CO may be easier to prepare and capture by the experiments than other sized neutral Ag n CO complexes [11].…”