Divergent oxidative conditions

Divergent reaction conditions are well exemplified in the case of reduction and oxidation steps. Consequently it is easier to run such systems sequentially [53]. This leads to the possibility of a linear-cyclic-parallel system for oxidation and reduction, proposed by Oberleitner and coworkers [54]. Here oxidative and reductive catalysts were combined to balance redox, followed by a further oxidation reaction. For example, alcohol dehydrogenase and enoate reductase, followed by Baeyer-Villiger monooxygenase, have been demonstrated in such a system. The last oxidation needs to be run with a parallel system or alternatively in a whole cell for cofactor recycle. 

The existence of non-equilibrium combustion products is important to at least two considerations. Firstly, the observed propellant performance may depart substantially from the predicted level. This departure may result in performance either less than or greater than the equilibrium predicted level. A striking example of greater than equilibrium performance is that of hydrazine monopropellant decomposition, table m-A-1. Another is that of ethylene oxide monopropellant, as mentioned in section n. B. 4., in which the equilibrium quantities of condensed carbon never are formed. Secondly, the non-equilibrium composition may have significant effects on the expansion process. In particular, nozzle kinetic calculations based on an assumed equilibrium composition initial condition may diverge significantly from expansions occurring from non-equilibrium initial conditions. 

Quinones have been extensively used for aromatization reactions in addition to the dehydrogenation of steroidal ketones and lactones. Interestingly, whereas chloranil (29) and a number of other quinones oxidize steroidal 4-ene-3-ones (32) selectively to 4,6>dienones (34),DDQ (28) results only in the formation of the 1,4-dienone (36 Scheme 21).This divergent b vior is best exfdained by the intermediacy of the kinetic enolate (35) in the case of the higher potential DDQ, but of the thermodynamic enolate (33) in the case of the less reactive quinones.Addic conditions need to be avoided if the cross-conjugated ketone (36) is the desired inoduct since under these conditions the 3,5-dienol (33) becomes both the kinetic and the thermodynamic enol, resulting only in the formation of the linear di-enone." ... 

Information on the amount of ozone generated by the lamp under various conditions is of interest to the research scientist, application engineer, and health officer. Many of the divergent views on the bactericidal effect and toxicity of ozone can be attributed to the methods of determination used by the authors as well as the purity of their gas. As an example, oxides of nitrogen were produced as a by-product by some of the early ozone generators. These oxides react with some of the reagents used for the measurement of ozone they have also been shown to be toxic (5, 26). Ultraviolet lamps do not produce oxides of nitrogen. 

---