Complex oxides, properties responsible

Thus, DFT calculations complemented by statistical thermodynamic analysis showed that a realistic Fe/ZSM-5 catalyst should contain a small fraction of isolated Fe + species at specific positions inside the zeolite chaimels, while the predominant part of iron is present in the form of oxygenated cationic iron complexes. The questions about which of these different extraframework complexes is actually responsible for the specific catalytic properties of Fe/ZSM-5 and what the role of other species were still open. They were addressed to a large extent only when the mechanisms of different catalytic reactions over different potential intrazeolite iron sites were thoroughly investigated by DFT calculations [43,46]. The influence of the nature and structural properties of Fe sites on two important catalytic processes promoted by Fe/ ZSM-5, namely, the selective oxidation of benzene to phenol and the direct catalj4ic N O decomposition, was investigated [43,46]. 

Even the highest quality mineral oil can be unsatisfactory in response of its resistance to oxidation and its behavior under pure boundary conditions, but it is possible to improve these characteristics by the addition of relatively small amounts of complex chemicals. This use of additives resembles in many ways the modification of the properties of steel by the addition of small amounts of other chemicals. It will be of value to have some knowledge of the effect of each type of additive. 

Oxidative drug metabolism is extremely complex and possibly the most poorly understood ADME property. Rapid metabolism is unacceptable for drug candidates, except for drugs whose metabolite is the active moiety, because it causes duration of action to be too short. Considerable work has focused on the liver enzyme CYP3A4, which is responsible for the metabolic clearance of approximately 50% of marketed drugs. Recent approaches used to model and understand drug metabolism include database matching, quantum mechanics, QSAR, and structure-based analyses. 

Use of the tripodal ligand Saltren creates a tetranuclear complex [Mn402(Sal-tren)2][MnCl4] 2CH3CN (172) having a fused open cubane structure without a carboxylate group. At 300 K the value of the effective magnetic moment for (172) is 5.1 /Ub, which decreases to 2.0 /iB at 4.2 K. The redox properties of (172) in propylene carbonate have been studied by cyclic voltammetry. Two oxidation responses are observed at = —0.32V and 0.43 V vs. SCE. 

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