Oxygen bond strength

Infrared, uv, nmr spectra (66), and photoelectron spectra have been reviewed (67). Physical properties of siHcon peroxides are summarized in Reference 43. Other physical properties, eg, dipole moments, dihedral angles, and heats of combustion ate Hsted in Reference 68. The oxygen—oxygen bond strengths of various diaLkyl peroxides have been reported (69). 

Tethwisch, D.G. and Dumesic, J.A. (1986) Effect of metal-oxygen bond strength on properties of oxides. 1. Infrared spectroscopy of adsorbed carbon monoxide and carbon dioxide, Langmuir, 2, 73. 

The application of 170 NMR spectroscopy to obtain structural information about polyoxoanions, mainly in nonaqueous solution, had been examined and discussed in detail (99). A very useful finding was that chemical shifts are determined largely by metal-oxygen bond strengths. An inverse correlation exists between the 170 shift and the shortest bond length to a given metal. In aqueous solution the existence of [Mo7024]6 could be confirmed by the use of 170 and "Mo NMR spectroscopy (100-104). Evidence for the existence of the three... 

Selectivity and Metal-Oxygen Bond Strength. The metal-oxygen bond strength could be measured as the differential heats of reoxidation of the reduced... 

VIII. A Generic Description of the Relationship between Metal-Oxygen Bond Strength and Selectivity... 

If these data are accepted as relevant, at least for the reduction process one of Sachtler and de Boer s conclusions (i.e., that activity should decrease with increasing metal oxygen bond strength) appears confirmed. 

Figure 8. Summary of catalytic reactions depending on metal-oxygen bond strength Q0...

The molybdenum-oxygen bond strength has been shown to weaken in direct proportion to an increased ionization potential of the A cations in several scheelite structured molybdates. Thus, it would be reasonable to assume that the nature of the A cation will have a profound effect on the molybdenum-oxygen bond strength which, in turn, will influence the activity and the selectivity of the catalysts. 

Boron-oxygen bond strengths (480-565 kJ mol 1) are greater than boron-carbon bond strengths (350-400 kJ mol 1). This reflects an interaction between the empty p orbital on boron and an electron pair in one of the oxygen s two filled non-bonding sp3 orbitals. 

The crystal face dependence and the activity of the various group 8-10 metals can be understood in terms of the metal-oxygen bond strength. On an active metal both O2 and H2 are dissociatively adsorbed, oxides are not formed under reaction conditions, and the heat of adsorption for Oacisis relatively low. 

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