Oxide ions, reaction with ethane

The effect of pH on the periodate oxidation of seven anilines has been investigated. " The kinetics of periodate oxidation of aromatic amines have been studied. " - " Periodate oxidation of oxalic acid is catalysed by Mn(II). " The reaction of ethane-1,2-diol with periodate has been investigated under a variety of conditions and the results compared with those of earlier work and analogous studies on pinacol. " The 104 ion is the primary reactant, with H5IO6 as a secondary reactant the reverse is true for pinacol. The complex observed in previous work is shown not to be an intermediate, but rather to deactivate the reactants. 

It is interesting to note that the catalysts that show good selectivities at the higher temperatures generally do not contain easily reducible metal ions, such as V, Mo, or Sb. Many of the catalysts for the lower-temperatures operation, on the other hand, contain these reducible cations. In a study using a Li-Mg oxide, it was established that gas-phase ethyl radicals could be generated by reaction of ethane with the surface at about 600°C (17). These radicals could be trapped by matrix isolation and identified by electron spin resonance spectroscopy. 

On the other hand, Ito et al. (99) found that the oxidative dimerization of methane to yield ethylene and ethane can be achieved with a high yield and good selectivity on Li-doped MgO catalysts. Since this pioneering work, many oxidic systems have been studied. Anpo et al. (100) found that surface sites of low coordination produced by the incorporation of Li into MgO play a vital role in the methane oxidative coupling reaction. Thus, although it was known that MgO acts as an acid-base catalyst, both the catalytic and photocatalytic activities of the MgO catalysts seem to be associated with the existence of surface ions in low coordination located on MgO microcrystals. 

Now let me come back to primary substitutions at the ferrocene nucleus. Together with Vil chevskaya, we phosphorylated ferrocene and its derivatives to triferrocenylphosphine oxides [263, 264). An unusual reaction, discovered in collaboration with Perevalova and Yur eva, was the direct cyanation of ferrocene with hydrocyanic acid in the presence of ferric chloride [265,272). Initially, cyanide attacks the iron atom of the ferricinium cation, then the cyanide group transfers to the ring while the iron is simultaneously reduced. The reaction was termed by us as the ricochet (from the metal to the nucleus) substitution it may be applied to many substituted ferrocenes and to the ruthenocenium cation [273), and it is now the simplest route to ferrocene carboxylic acids through their nitriles. Further, ferrocene was studied in acid-medium reactions with oxo compounds. With aldehydes [274), the reaction was complicated by the transformation of ferro-cenylalkyl carbinol formed Initially via the carbonium ion, followed by transformation to a radical which, in its turn, was coupled to 1,2-bis-(ferrocenylalkyl)ethane (27.5). The reaction with acetone led to 2,2-di-ferrocenylpropane (276). 

Zemski KA, Justes DR, Castleman AW Jr (2001) Reactions of group V transition metal oxide cluster ions with ethane and ethylene. J Phys Chem A 105 10237... 

After much testing, chemists developed a compound that stabilizes paper diethyl-zinc [Zn(C2H5)2]. Diethylzinc is volatile so it can be sprayed onto books. It reacts with water to form zinc oxide (ZnO) and gaseous ethane (C2Hg). (a) Write an equation for this reaction, (b) ZnO is an amphoteric oxide. What is its reaction with H+ ions ... 

The reactivity of doubly charged rare earth cations with small hydrocarbons was also investigated by FTICR-MS. In early studies, Freiser and coworkers examined reactions of Sc and Y " " (Hill et al., 1997), as well as La (Ranasinghe et al., 1992), with linear Cj-Cg alkanes combinations of electron transfer, hydride transfer, carbanion transfer, dehydrogenation, and alkane-loss products were observed. None of the metal ions reacted with methane, and La + was also unreactive with ethane. Since the metal dications have only one valence electron, oxidative addition to form two covalent bonds to the metal center is not possible, and alternative multicentered mechanisms were proposed. Another interesting aspect of these studies was the observation... 

Oxidative Dehydrogenation of Ethane. The dehydrogenation of alkanes also occurs, but in a catalytic manner, over molybdenum supported on silica (22,23). In addition to the stoichiometric reactions, the role of the 0 ion in this catalytic reaction is further suggested by the observation that N2O is an effective oxidant at temperatures as low as 280°C, but no reaction is observed at these temperatures with O2 as the oxidant (22). It should be noted that at moderate temperatues N2O gives rise to 0 , whereas O2 yields O2 over Mo/Si02. Under steady-state conditions the rates of formation of C2Hi were in the ratio of 7 1 at 375°C and 3.7 1 at 450°C when N2O and O2 were used as the oxidants, respectively (23). ... 

Straight-chain alkanes also efficiently react with ozone in Magic Acid at —78°C in SO2CIF solution. Ethane gave protonated acetaldehyde as the major reaction product together with some acetylium ion (Scheme 5.62). Reaction of methane, however, is rather complex and involves oxidative oligocondensation to terf-butyl cation, which reacts with ozone to give methylated acetone (Scheme 5.63). 

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