Cyclohexane, Research Octane

QOOH chemistry will then remain of considerable importance for substituted cyclohexanes and may be influential in determining research octane numbers. 

Figure 6.9.1 Research octane numbers (ROMs) of hydrocarbons of different chain length and molecular structure (naphthenes cyclopentane, cyclohexane, methylcyclohexane, 1,3 dimethylcyclohexane, and 1,3,5-trimethylcyclohexane aromatics benzene, toluene, and m-xylene).

PhI02 is rather bulky and plugs the pores, thus preventing further access of reactants to the active sites [49-50,63-64]. Therefore turn-overs are quite low when PhIO is used as oxidant. For the oxidation of methyl cyclohexane on TMPcY [49-50,63-64] and of cyclohexane on Fet.BuPcY [67] turn-overs are 5.6 and 7.6 respectively. It should be noted that the reported turn-overs for oxidations with PhIO correspond to conversions of less than 1 substrate molecule per two supercages, or to total conversions of less than 0.1 %. Therefore the observed activities and selectivities may be influenced by sorption effects. Furthermore iodosobenzene is a rather expensive oxidant and not practical to use because of its low solubility in solvents. Therefore some researchers tend to use other oxidantia such as air [65,66] and tertiary butyl hydroperoxide (t-ButOOH) [57]. In the oxidation of n-octane with t-ButOOH turn-overs as high as 6000 have been reported [57]. 

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