Reactions clusters

Trevor D J, Whetten R L, Cox D M and Kaldor A 1985 Gas-phase platinum cluster reactions with benzene and several hexanes evidence of extensive dehydrogenation and size-dependent chemisorption J. Am. Chem. Soc. 107 518... 

Silicon cluster reactions are an example of a newly emerging field of research which is very amenable to study with electronic structure methods. This exercise will examine the potential surface for silicon cation reacting with silane (SiH4). Such reactions are central to the growth of large silicon clusters, which occurs by sequential additions of -SiHj ... 

Silicon Cluster Reactions S t 2 Reaction Hydration Reactions... 

Figure 7. Time-of-flight mass spectra showing results of platinun cluster reactions with benzene. The lower trace is clean metal without reactant. The upper trace is with the pulsed addition of. 21 % benzene in heliun. The notation indicates the nmber of adducts on each metal cluster. The metal cluster are all two photon ionized, while the observed products are single photon ionized, hence the enhancement of the product over metal signals. Reproduced from Ref. 17.

Even if atomic oxygen-carbon cluster reactions are rapid, as is assumed in the new neutral-neutral model, the synthetic power of this model can be recovered if exothermic hydrogen atom abstraction reactions of the sort,... 

Recently, similar findings133 have been made in studies of the photoionization of NO containing water clusters134 which established that the cluster reaction analogous to the last step in reaction 36 occurs for n > 4. 

Another interesting situation which demonstrates the role of solvation on cluster reactions, with particular relevance to identifying mechanisms of possible importance in the condensed phase, concerns the initiation of electron transfer reactions. Interesting examples include those initiated through Penning ionization.161... 

KriP is readily calculated by considering the inner-shell clustering reactions... 

Vacher R., Le Due E., and Fitaire M. (2000). Clustering reactions of HCNH+, HCNH+ (N2) and HCNH+ (CH4) with ethane application to Titan atmosphere. Planetary and Space Science 48 237-247... 

Tandem mass spectrometry H6,i46) both stationary 116> and flowing afterglow-methods 118,147) and drift tube techniques U6> have also been applied to some of the clustering reactions. Results for the gas-phase solvation of H+ by H2O and NH3 generally agree well with the values obtained by high pressure mass spectro-metric observations 148). 

Figure 11. Van t Hoff plot [ln(/(g<,) vs. 7 ] for the clustering reaction of Cl onto CH3CI, from which A/-/° and AS for the clustering reaction can be derived.

Anilinocyclophosphazene, 21 72 Anionic carbonyl cluster, reaction with cationic mononuclear complexes, 30 155-158... 

Heptadecararbonylhexaosmium clusters, reactions with nucleophiles, 30 196 Heptafluorides, structures, 27 108 Heptafluoro-n-propyl phosphorus compounds, 3 378... 

In order to confirm the saturation in 9a, free-energy changes for the following stepwise clustering reactions were calculated ... 

The complex FeCo2(CO)9(PC6H5) is black in the crystalline state and purple in solution. It is moderately air sensitive. It has a low solubility in aliphatic hydrocarbons and a moderately good solubility in aromatic hydrocarbons. In cyclohexane solution it shows Vco bands at 2101 (vs), 2059 (vs), 2048 (vs), 2039(vs), 1981 (w), 1969(w)cm 1. It has been used for various types of basic metal cluster reactions.16... 

In a 1988 article, Kroto observed, Initially, cluster reactions were probed which showed that C (n > 30) clusters did indeed react with H and N to form polyynes, which had been delected in space, a result satisfyingly consistent with the idea of a stellar source of interstellar chains. The larger clusters were totally inert, and as the experiments progressed, it became impossible to ignore the antics of the Cm peak which varied from relative insignificance to total dominance, depending on the clustering conditions. 

Reaction of the bis(diphenylphosphino)methane (dppm) complex PdPt-(yi-dppm)2Cl2 (132) with carbonylate anions affords several tri- and tetranuclear clusters. Reactions are outlined in Scheme 7. Treatment of 132 with 2 mol equivalents of [Fe(CO)3(NO)] (796,797), [Co(CO)4] (196,198), or [Mn(CO)5] (196,197) results in the tetranuclear spiked triangular clusters 133,134, or 135. Crystal structures on the dipalladium analogues of 134 and 135 have been reported (797,799). Grossel et al. (136) and Braunstein et al. (200) have independently reported that reaction of 132 with 1 mol equivalent of [Fe(CO)4]2 at ambient temperatures leads to an inseparable 1 1 mixture... 

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