Observation of Magic Numbers within NO/NH₃ Mixed Cluster Ions

Abstract

The metastable decomposition of photoionized NO/NH 3 clusters has been investigated employing a reflectron time-of-flight mass spectrometer. The metastable dissociation spectra of the most prominent cluster ion species NO + (NH 3 ) n (3 e n e 28) show that the rate coefficient for the loss of one NH 3 molecule from the cluster rapidly increases up to n ) 13 and thereafter is nearly independent of the cluster size. This is interpreted as evidence of a stable structure that consists of a central NO + ion surrounded by a first solvation shell of 12 NH 3 molecules.

Nitrosamide, (H2NNO), formation within [(NO)m(NH3)n]+ clusters: Theory and experiment

“…However, it appears to be unlikely that such protonated cluster ions are formed within clusters because we saw no evidence supporting the formation of the protonated form in our previous study of NO/NH 3 [37] and NO/ROH [32][33][34]41] systems, even though protonated cluster ions such as (NH 3 ) n H + and (CH 3 OH) n H + are mainly observed when NH 3 and CH 3 OH, respectively, are expanded.…”

“…A detailed description of the reflectron time-of-flight mass spectrometer (RTOFMS) instrument has been provided elsewhere [36,37]. In brief, the neutral heteroclusters were expanded through a pulsed nozzle (General Valve Co., IOTA ONE) with an 800 m orifice diameter.…”

“…A series of neat protonated ammonia clusters (NH 3 ) n H + , are also observed and represented by A n . In previous work [37], we observed that the mixed cluster ions, [(NO)(NH 3 ) n ] + , can be considered as having a structure where the ion core NO + is solvated by the ammonia molecules. This picture of NO + solvated by NH 3 is different from that for the mixed cluster ion [(NO)(H 2 O) n ] + [38,39] where the structure of [NO(H 2 O) n ] + cluster ion depends on the cluster sizes n; for n ≤ 3, the ion core is NO solvated by water molecules, while, for n ≥ 4, the [NO(H 2 O) n ] + the cluster ion now exists in the form (H 2 O) n−1 H + ·HONO.…”

Photochemical Generation of Methane within NO−Ethene Heteroclusters

“…The study of ion−molecule reactions of the NO + cation has been the subject of much research due to its importance in atmospheric chemistry. , Heterogeneous reactions of NO on droplets and particles are of particular interest both because of their importance and the difficulty of modeling their effect on stratospheric and tropospheric chemistry, especially their interaction with ozone formation . A number of studies of NO have been conducted to explore both homogeneous and heterogeneous cluster − formation. One of the key results of this work is the tendency of NO clusters to show even−odd intensity alternation.…”

“…8 Another key result is that previous multiphoton ionization and electron impact studies have demonstrated that heterogeneous clusters containing NO tend to exhibit a rich and not always predictable series of ion-molecule reactions. [5][6][7][8][9][10] Pure ethene clusters have also been the subjects of much research [11][12][13][14][15][16][17][18] mainly in connection with the tendency of clusters of unsaturated hydrocarbons to polymerize in electron impact studies. Reaction of NO-ethene mixtures on metal catalysts has been the subject of a number of studies mainly with respect to oxidation of the NO.…”