Metals basic

The class of compounds identified as basic aluminum chlorides [1327-41 -9] is used primarily ia deoderant, antiperspirant, and fungicidal preparations. They have the formula Al2(OH)g where x = 1 5, and are prepared by the reaction of an excess of aluminum with 5—15% hydrochloric acid at a temperature of 67—97°C (18). The same compounds are obtained by hydro1y2ing aluminum alkoxides with hydrochloric acid (19,20) (see Alkoxides, METAl). Basic aluminum chloride has also been prepared by the reaction of an equivalent or less of hydrochloric acid with aluminum hydroxide at 117—980 kPa (17—143 psi) (20). 

Metal basicity and cooperative effects in the reactions of dinuclear pyrazolato rhodium complexes 98PAC779. 

The effect of metal basicity on the mode of reactivity of the metal-carbon bond in carbene complexes toward electrophilic and nucleophilic reagents was emphasized in Section II above. Reactivity studies of alkylidene ligands in d8 and d6 Ru, Os, and Ir complexes reinforce the notion that electrophilic additions to electron-rich compounds and nucleophilic additions to electron-deficient compounds are the expected patterns. Notable exceptions include addition of CO and CNR to the osmium methylene complex 47. These latter reactions can be interpreted in terms of non-innocent participation of the nitrosyl ligand. 

Carbyne complex chemistry of osmium and ruthenium is discussed in this section. These studies demonstrate clearly the parallels that exist between the metal-carbon bonds in carbene and carbyne complexes and again emphasize the importance of metal basicity in determining complex reactivity. 

Coke throughput Hot metal production rate Slag volume Ore availability Elements in slag Elements in metal Basicity Sales limits... 

One-Pot Multistep Synthesis of Ketones on Bifunctional Zeolite Catalysts. One-pot multistep reactions constitute an elegant and efficient way to decrease the number of chemical and separation steps, hence, to develop greener synthesis processes. Bifunctional metal-acidic or metal-basic zeolite catalysts, which can be prepared easily with the desired properties (e.g., distribution of the... 

FORMATION OF MONODISPERSED METAL (BASIC) CARBONATES IN THE PRESENCE OF UREA... 

One efficient and convenient way to produce uniform particles of metal (basic) carbonates has been by aging metal salt solutions in the presence of urea at moderately elevated temperatures. Under these conditions, urea decomposes by releasing carbonate ions (CO32-, HC03 ) with simultaneous increase in the pH. 

Table 7.1.1 Summary of Monodispersed Metal (Basic) Carbonate Particles Obtained by Aging Metal Salt Solutions in the Presence of Urea...

By carefully heating the powders of metal basic carbonates, the particles can be converted to oxides while preserving their morphology and dispersibility. Figure... 

Again, decomposition of urea in an acidic metal salt solution in the presence of preformed particles can yield homogeneous layers of variable thicknesses of metal basic carbonates on the core materials of different chemical composition. In order to obtain uniformly coated particles (rather than a mixture of the latter and of the independently precipitated coating material), a balance between the amount of the initial dispersed matter and the concentration of the reacting solutes must be optimized. 

However, if the contribution of the potential difference of the metal (basically gM) should be included into the total capacity, it would be also in series with the other solution capacities (Fig 6.68), that is,... 

These observations show that the catalytic reactions using complexes of different diphosphine ligands are likely to involve different reaction mechanisms. Also, subtle variations in metal basicity and catalyst stereochemistry can affect significantly the rate and mechanism of reaction. Therefore it is highly risky to generalize a reaction mechanism to seemingly similar catalysts. Our current research is directed towards determining these mechanistic differences. 

In so far as the decrease in chemical reactivity is an indication of diminished transition metal basicity, it was proposed143 that the thiocarbonyl complex is less basic than its carbonyl analogue. This conclusion is substantiated by the spectral shifts in Table 22 and is also in agreement with molecular orbital calculations which predict the thiocarbonyl complex to be less basic than the carbonyl complex155,156. 

G. Alefeld and J. Volkl (eds), Hydrogen in Metals—Basic Properties, Springer-Verlag, Berlin (1978). 

Heavy metals, like lead and mercury, have been recognized as toxic poisons for centuries. Further, toxic concentrations of mercury, for example, can trigger several effects like autoimmune diseases, infections, unexplained chronic fatigue, depression, nerve impairment, memory problems, decreased mental clarity, and bowel disorders. For several decades, mercury vapor exposure has caused severe health problems among chloralkali workers. This is only an example. It may be repeated that education can effectively minimize exposure to hazardous metals. Basic information and training for proper handling of toxic chemicals will reduce potential adverse health effects. 

Materials define the face of society. Initially, since prehistoric times - and to this day - materials were selected amongst those available in nature. These included, besides stones and metals, basic ingredients obtained from plants, crops, and animals in the form of, for example, wood, flax, wool, and leather. Materials use was a skills-based activity perfected by artists and guild-members handed from one generation to the next. 

Metal basicity may be probed by protonation. While neutral species such as Fe(CO)s are only weak bases, metal carbonyl anions are readily protonated to give metal hydrides. The basicity is increased by the presence of ligands such as Cp, and Cp2ReH for example has a basicity comparable to that of ammonia. Examples are ... 

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