Gold carbonyl, structure

Neutral and charged gold carbonyl species have also been observed on gold field emitter tips upon interaction with CO gas at room temperature in the presence of high electrostatic fields. The adsorbed complexes and the desorption pathways were identified using time-of-flight mass spectroscopy. [(CO)Au] species are more abundant than [Au(CO)2] species. The product distribution was rationalized by DF calculations of the electronic structure of the complexes.291... 

Infiared spectra of CO adsorbed on nanometric gold particles supported on different supports, both oxidised and reduced, are reported. Depending on the nature of the supports, on the pretreatments and on the size of the gold nanopaiticles, different gold carbonylic species have been evidenced. The electronic and structural properties of gold nanoparticles and the electron-donating effects of reducible supports are shown to be relevant in determining the chemisorption and catalytic properties of the samples. 

Zhu, Z., Cameron, B.R. and Skerlj, R.T. (2003) Cycloauration of substituted 2-phenoxypyridine derivatives and X-ray crystal structure of gold, dichloro[2-[[5-[(cyclopentylamino)carbonyl]-2-pyridinyl- N]oxy]phenyl- C]-, (SP-4-3)-. Journal of Organometallic Chemistry, 677, 57. 

Another way to produce acetic acid is based on a carbonylation of methanol in the so called Monsanto process, which is the dominant technology for the production of acetic acid today [15]. Acetic acid then is converted to VAM by addition of ethylene to acetic acid in the gas phase using heterogeneous catalysts usually based on palladium, cadmium, gold and its alloys (vinylation reaction 3 in Fig. 2) [16] supported on silica structures. 

The acyl cation (acylium ion, oxocarbonium ion) is a resonance hybrid of the two main contributing structures 192 and 192a. The importance of structure 192a is indicated, for instance, by the high frequency carbonyl absorption (2200-2300 cm-1) observed in acyl cations generated from acyl halides and Lewis acids (Olah et al., 1962, 1963 Bethell and Gold, 1967). 

Fielicke A, von Helden G, Meijer G, Pederson D, Simard B, Rayner D (2005) Gold cluster carbonyls Saturated adsorption of CO on gold cluster cations, vibrational spectroscopy, and implications for their structures. J Am Chem Soc 127 8416... 

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