Molecular oxygen dioxygenation with

The dioxygen complexes which have been discussed may be prepared either by reaction of a metal complex with molecular oxygen or with peroxidic species. Both... 

Of course, the current direction is to synthesize complexes which will more closely mimic hemoglobin and myoglobin and to develop oxygenactivating species in general. In 1973 and 1974, several model systems were devised. We will thus be concerned here with the interaction of molecular oxygen (dioxygen) and carbon monoxide with metalloporphyrin complexes as models of biologically important hemoproteins. 

The possibility of a radical mechanism is supported by the observation of the accelerating effect of molecular oxygen on the cyclopropanation. Miyano et al. discovered that the addition of dioxygen accelerated the formation of the zinc carbenoid in the Furukawa procedure [24a, b]. The rate of this process was monitored by changes in the concentration of ethyl iodide, the by-product of reagent formation. Comparison of the reaction rate in the presence of oxygen with that in the... 

Dioxygen is a cheap and ideal source of oxygen but it is very difficult to activate and there are relatively few examples of 02 oxidations catalyzed by zeolite-encapsulated complexes. Encapsulated CoPc is active for the oxidation of propene to aldehyde, whereas the free complex is inactive.104 A triple catalytic system, Pd(OAc)2, benzoquinone, and a metal macrocycle, was used to oxidize alkenes with molecular oxygen at room temperature.105 Zeolite-encapsulated FePc106-108 and CoSalophen (Scheme 7.5)107109 complexes were used as oxygen-activating catalysts. With the use of a Ru complex instead of Pd(OAc)2 in the triple catalytic system, primary alcohols can be oxidized selectively to aldehydes.110... 

The vast majority of the studies in this field relate to the oxidation of iron ions by molecular oxygen. The oxidation of Fe2+ is first-order with respect to dioxygen and,... 

Despite the above aspects of the interaction of molecular oxygen with metal fragments, we will limit our electrochemical discussion to the reactivity of transition metal complexes with molecular oxygen in the context of modelling the dioxygen transport. 

These Co(II) complexes react with molecular oxygen by a two stage mechanism a first step with rapid formation of a 1 1 metal-dioxygen complex, followed by the slower formation of a 2 1 complex (believed to be responsible for the irreversible coordination of oxygen) according to the sequence ... 

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