High-pressure chemical reactions electronic structure

First we study the surface structure and chemisorption characteristics of crystals cut along different crystallographic orientations. Then a well-chosen chemical reaction is studied at low pressure to establish correlations between reactivity and surface structure and composition. Below 10 4 Torr the surface can be monitored continuously during the reaction with various electron spectroscopy techniques. Then the same catalytic reaction is studied at high pressures (1-100 atm) and the pressure dependence of the reaction rate is determined using the same sample over the nine orders of magnitude range. Finally, the rates and product distributions that were determined at... 

Molecular ions and ions closely related to them can also be generated by an alternative technique, chemical ionization. This method is based on the reaction of the substrate molecule with a reactive ion, generated by electron bombardment of appropriate gases which are present at relatively high pressures. Substrates belonging to different structure types can be oxidized selectively with specific positive ions. 

His research interests include electron transfer (particularly over long distances using oligopeptides and proteins as structural motifs), radiation chemistry, inorganic reaction mechanisms, the reactivity of energetic inorganic species produced by radiation, the effects of high pressure on chemical reactivity, reactions in supercritical solvents, and the development of new accelerators and new detection techniques for pulse radiolysis. 

A high-performance liquid chromatographic/atmospheric pressure chemical ionization-mass spectrometric (HPLC/APCI-MS) method has been developed for the determination of the pesticide clofentezine (3,6-bis(2-chlorophenyl)-l,2,4.5-tetrazine) in plum-, strawberry-, and blackcurrant-based fruit drinks <1995RCM1441>. The structural characterization and the mass spectrometric behavior of pyridazinofurocoumarins, prepared by the inverse electron demand Diels-Alder reaction between furocoumarinones and 3,6-bis(methoxycarbonyl)-l,2,4,5-tetrazine, were studied under electron ionization conditions via sequential product ion fragmentation experiments <2004RCM564>. 

Reaction 2 is used in an electron cyclotron (ECR) plasma to produce c-BN at 675°C on an experimental basis.Cubic boron nitride has a structure similar to diamond with extreme hardness and chemical resistance and is normally obtained by high-pressure processing. 

It has been known for many decades that different crystal faces of the same element display subtly different chemical properties. This could be for a number of reasons, including differences in the electronic band structure at the surface, or due to the fact that different structures stabilize different intermediates or transition states to different extents for geometrical reasons. Clearly this is an important issue in catalysis, but maintaining the crystal faces in a clean, well-defined state before the reaction (which might be at high pressure) has been a challenge to many researchers in this field. 

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