Cuprous oxide experimental data

Snider and Kwon use either cupric triflate and cuprous oxide or ceric ammonium nitrate and sodium bicarbonate as single-electron oxidants to convert d,s- and ,C-unsaturated enol silyl ethers 9 stereoselectively to the tricyclic ketones 14 in excellent yields [83, 84]. Based on comparison with other experimental data and literature results, the authors try to distinguish between several possible intermediates and propose the following mechanism with a very electrophilic radical cation 10 as the key intermediate. 

Some experimental data obtained in high temperature oxidation studies indicate that the above might be a fruitful field of investigation. Harris et al (72) have shown that the nucleation and growth of cuprous oxide on copper are closely related to dislocations in the metal. Gulbransen and Andrews (73) report data which indicate that the growth of oxide nuclei on iron is related to the number and arrangement of dislocations in the metal crystal. 

Turning to nickel oxide, the thermochemical data of Tables II and IV show that the oxidation via the CO3 complex should be more difficult than on cuprous oxide or cobaltous oxide. The various reaction paths are shown schematically in Fig. 4. Because of the increase in the heat of formation of the complex, reaction (4) is now strongly endothermic and the reaction will be subject to poisoning. The poisoning effect has been confirmed experimentally, not only in our own studies, but also by Roginskii and Tselinskaya (SO) and by Winter (21, 22). The reaction CO(g) - - =... 

Characterizing and modeling cuprous chloride presents a challenge to investigators in two ways. Experimental data is quite difficult to obtain due to the rapid oxidation of the cuprous to cupric ion in air. For the investigator attempting to model this species in solution, there is disagreement in the experimental data and uncertainty in thermodynamic data primarily because of the possibility of numerous complex forms of Cu. ... 

Copper is not expected to follow Cabrera-Mott inverse logaridimic kinetics since its oxide is a modifier according to Table 1. In fact, copper follows direct logarithmic kinetics. This was emphasized by results (Table 2) from die analysis of experimental data [5e,9] including the results shown in Figure 2. No attempt is made here to apply the Fehlner-Mott direct logarithmic expression, Eq. (5) above. This is because the evidenee for oxide recrystallization with time is very complex. Onay [39] reported on the formation of multiphase, multilayer scales on copper at 300°C. He foimd that they result from the dissociation of compact cuprous oxide scale that has lost contact with the copper substrate. 

---