Alternative Anions

Catalyst Composition CuO/ZnO/AljO (wt%) BET (m g- ) Cu surfece area (m g- ) Temperature of calcination (K) 

In summary, the same conclusion can be drawn using citrate as for the ternary catalysts prepared by coprecipitation with aqueous Na2C03 the activity of a Cu/ZnO/AhOs catalyst correlates with the copper surface area, and the larger the specific Cu surface area the higher is the activity for the synthesis of methanol. 

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The absorption spectrum of this nonstoichiometric phase forms the basis for the formerly much-used qualitative test for zinc oxide yellow when hot, white when cold . Alternatively, anion sites can be left vacant, e.g. ... 

As the above half-reactions proceed, a surplus of positive ions (Zn2+) tends to build up around the zinc electrode. The region around the copper electrode tends to become deficient in positive ions as Cu2+ ions are consumed. To maintain electrical neutrality, cations must move toward the copper cathode or, alternatively, anions must move toward the zinc anode. In practice, both migrations occur. 

The structure of a green rust LDH-type material with the formula [Fe 4Fe 2(OH)i2]S04-ca. 8H2O has been determined by Rietveld analysis [157]. The material exists as a one-layer polytype with the interlayers containing two planes of sulfate and water molecules giving a basal spacing of 1.1011 nm. The sulfate ions are oriented with their C3 axes perpendicular to the layers and alternate anions point up and down (as shown earlier in Fig. 14) and form a superlattice with parameter a = UoV5 = 0.5524 nm (Fig. 39). 

Aminoamides such as VI/4 are instable they rearrange under acid or base (shown) catalysis to VI/91. The mechanism of this reaction is shown in Scheme VI/2 [3]. The driving force of this transamidation reaction seems to be the formation of the anion VI/8, which is resonance stabilized and so more attractive than the alternative anion VI/5. 

Reaction of Hydrides. The donor semi-bridging interaction of the carbonyls in 1 might render them more susceptible to nucleophilic attack by such reagents as hydrides. We reasoned that the formation of n2-formyl species, e.g., IV, or alternatively, anionic metal hydrides, e.g., V, might result. The actual reaction of l with Et3BH is consistently more complex than anticipated (-3.31. 

Slow diffusion of deoxygenated water solutions of GdCb-61120 and Li [TCNQ] (1 1 ratio) yields crystals of [Gd2(TCNQ)5(H20)9][Gd(TCNQ)4 (H20)3] -4H20 [86], which consist of alternating anionic and cationic layers perpendicular to the c-axis, exhibiting different ratios of Gd(III) and TCNQ radicals, both of which are based on a 2D-network of Gd(III) ions coordinated to TCNQ radical anions (Figure 9.9). The different ratios of Gd(III) and TCNQ-in the two independent layers leads to the unusual situation of having both cationic and anionic networks. 

Enderby and colleagues were the first to study molten salts. Among others, they showed that molten NaCl has a structure which is mainly dominated by alternating anion and cation interactions, which extend up to three anion-cation pairs. As a result, the molten NaCl is highly structured [115, 116]. Igarashi et al. [117] have examined the liquid structure of a LiF-NaF-KF eutectic mixture. For the ion pairs Li-F, Na-F, and K-F, the nearest neighbor coordination and distances were almost identical to those found in the melts of the individual components. 

An alternative anionic wetting agent is sodium dodecylbenzene sulphonate, with a branched alkyl chain... 

A number of chambers called diluting and concentrating cells are separated by alternating anion and cation membranes and are arranged between two electrodes. This is shown in Figure 36-8, p. 426. 

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