Magnesium oxide interactions

Calculations of the interaction energy in very fine pores are based on one or other of the standard expressions for the pair-wise interaction between atoms, already dealt with in Chapter 1. Anderson and Horlock, for example, used the Kirkwood-Miiller formulation in their calculations for argon adsorbed in slit-shaped pores of active magnesium oxide. They found that maximum enhancement of potential occurred in a pore of width 4-4 A, where its numerical value was 3-2kcalmol , as compared with 1-12, 1-0 and 1-07 kcal mol for positions over a cation, an anion and the centre of a lattice ceil, respectively, on a freely exposed (100) surface of magnesium oxide. 

D Ercole, A., Giamello, E. and Pisani, C. (1999) Embedde-Cluster Study of Flydrogen Interaction with an Oxygen Vacancy at the Magnesium Oxide Surface, J. Phys. Chem. 103, 3872-3876. 

N.U. Zhanpeisov et al., Cluster quantum chemical study of the interaction of dimethyl methylphosphonate with magnesium oxide. J. Phys. Chem. 98, 10032-10035 (1994)... 

Magnesium oxide is considered to exhibit basic properties (20). It is thus not unexpected that neither Br nsted nor Lewis acid sites could be detected by ammonia adsorption (180,181). Hydrogen-bonding is the only type of interaction that ammonia probably undergoes with surface oxide ions on dehydroxylated surfaces (180) and with surface OH groups on hydroxylated surfaces (181). 

Tretyakov and Filimonov (219) describe a coordinative interaction between benzonitrile and aprotic sites on magnesium oxide, and Zecchina et al. (256) came to the same conclusion for the adsorption of propionitrile, benzonitrile, and acrylonitrile on a chromia-silica catalyst. Chapman and Hair (257) observed an additional chemical transformation of benzonitrile on alumina-containing surfaces, which they describe as an oxidation. Knozinger and Krietenbrink (255) have shown that acetonitrile is hydrolyzed on alumina by basic OH- ions, even at temperatures below 100°C. This reaction may be described as shown in Scheme 2. The surface acetamide (V) is subsequently transformed into a surface acetate at higher temperatures. Additional reactions on alumina are a dissociative adsorption and polymerizations (255) analogous to those observed for hydrogen cyanide by Low and Ramamurthy (258), and a dissociative adsorption. Thus, acetonitrile must certainly be refused as a probe molecule and specific poison. 

This review is mainly devoted to summarize the results of the theoretical studies of organophosphates interacting with catalytic surfaces (transition metal and metal oxide). Therefore, we need to mention that to the best of our knowledge, there were published only a few theoretical works addressing this problem. Some theoretical studies of the interactions of organophosphate compounds with clay minerals and magnesium oxide were also published. 

Zhanpeisov NU, Zhidomirov GM, Yudanov IV, Klabunde KJ (1994) Cluster Quantum Chemical Study of the Interaction of Dimethyl Methylphosphonate with Magnesium Oxide, J Phys Chem 98 10032-10035... 

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