Transition metal INDEX

The transition metal index which appears only in Volume 2 was prepared from the entries in classes 71-86. Since metal complexes are classified in terms of the ligands this index provides an alternative search for e.g. all iridium complexes. 

Viable glass fibers for optical communication are made from glass of an extremely high purity as well as a precise refractive index stmcture. The first fibers produced for this purpose in the 1960s attempted to improve on the quahty of traditional optical glasses, which at that time exhibited losses on the order of 1000 dB/km. To achieve optical transmission over sufficient distance to be competitive with existing systems, the optical losses had to be reduced to below 20 dB/km. It was realized that impurities such as transition-metal ion contamination in this glass must be reduced to unprecedented levels (see Fig. 

Figure 4.27 presents steady-state potentiostatic r vs 0Na results during NO reduction by H2 on Pt/p"-Al203f2 PInb values well in excess of 4000 are obtained for 0Na values below 0.002. This is due to the tremendous propensity of Na to induce NO dissociation on transition metal surfaces. Since Plj is often found to be strongly dependent on 0, (Figs. 4.26 and 4.27), it is also useful to define a differential promotion index pij from ... 

Author Index for appendix (pp. 455-468) to the article Transition Metal Chemistry 1971 by M. I. Bruce. 

Besides the applications of the electrophilicity index mentioned in the review article [40], following recent applications and developments have been observed, including relationship between basicity and nucleophilicity [64], 3D-quantitative structure activity analysis [65], Quantitative Structure-Toxicity Relationship (QSTR) [66], redox potential [67,68], Woodward-Hoffmann rules [69], Michael-type reactions [70], Sn2 reactions [71], multiphilic descriptions [72], etc. Molecular systems include silylenes [73], heterocyclohexanones [74], pyrido-di-indoles [65], bipyridine [75], aromatic and heterocyclic sulfonamides [76], substituted nitrenes and phosphi-nidenes [77], first-row transition metal ions [67], triruthenium ring core structures [78], benzhydryl derivatives [79], multivalent superatoms [80], nitrobenzodifuroxan [70], dialkylpyridinium ions [81], dioxins [82], arsenosugars and thioarsenicals [83], dynamic properties of clusters and nanostructures [84], porphyrin compounds [85-87], and so on. 

Table 3 shows the values of M and T evaluated for all the transition metals in terms of Eq. (1) and (3). Comparison of these estimates with the values in Table 1 shows satisfactory agreement in most polynuclear systems. While it is not suggested that there is any necessary relation between M, f and A//f (M, g), it is clear that these empirical relationships provide a useful index of the strengths of bonds in polynuclear systems and give at least some indication of the magnitude of b.e.cs in other systems. 

This group contains many powerful oxidants, the most common being sodium peroxide. Undoubtedly one of the most hazardous is potassium dioxide or superoxide, readily formed on exposure of the metal to air (but as the monovalent O2 ion it is not a true peroxide). Many transition metal peroxides are dangerously explosive. Individually indexed peroxides are ... 

These oxidations suffer from the fact that the high selectivities are only observed at low conversions (<7%). At higher conversions, the carboxylic acid products leach the transition metals out of the zeolite framework into solution where the selectivity index is much lower [63]. As these reactions proceed, the 3 -I- oxidation states of the metal ions return to their 2 -I- states, accompanied by their characteristic color change. In the case of MnAlPO-18, the spent catalyst (Mn ) was washed with methanol and reactivated in dry air at 550°C and successfully recycled (Mn Mn ) twice without appreciable loss of activity [64]. 

No structure analyses on transition metal compounds NasMeFe have been performed yet, but recently Vollmer 316) indexed a powder diagram... 

Low Miller index surfaces of metallic single crystals are the most commonly used substrates in LEED investigations. The reasons for their widespread use are that they have the lowest surface free energy and therefore are the most stable, have the highest rotational symmetry and are the most densely packed. Also, in the case of transition metals and semiconductors they are chemically less reactive than the higher Miller index crystal faces. 

There is an extensive literature on ammines and the Chemical Abstracts 10th Collective Index (1977-81) has four pages under this heading. One important parameter for this class of compound is the metal-nitrogen bond length and Table 1 lists some of the available data. Transition metal-NH, bond energies have also been calculated.100... 

The arrangement of the syntheses in the first part of Volume XIV is divided into three chapters, namely, Phosphorus Compounds, Non-Transition-Metal Compounds, and Transition-Metal Compounds. The reader is advised to seek particular compounds in the subject or formula indexes. The indexes at the end of this volume are cumulative from Volume XI through Volume XIV. 

In addition to the examples discussed above, where the hybrid materials were derived from the alkoxides of the transition metals, it is necessary to mention that M(OR) (M = Ti, Zr) are the typical inorganic chain-forming reagents often added to the silicon alkoxides to play the cross-linking role between the organosilicon units, which increases the hardness and the refractive index of the hybrid materials. M(OR)n were also found to catalyze the condensation of siloxanes. 

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