Zinc formate

The water solubiUty of zinc compounds varies greatly, as shown in Table 1. Water-soluble compounds not Hsted are zinc formate [557-41-5] chlorate [10361-95-2] fluorosihcate [16871 -71 -9] and thiocyanate [557-42-6]. Also, the water-soluble amino and cyanide complexes have many uses. 

Zink-fahlerz, n. tennantite. -farbe, /. zinc paint, -feile,/., -feilspkne, m.pl. zinc fihngs. -folie, /. zinc foil, -formiat, n. zinc formate. 

None 100 Zinc formate 44 Zinc carbonate 42 Zinc sulfate 43 Zinc oxalate 39 Zinc chloride 8 Zinc acetate 7 Zinc benzoate 2 Zinc 3,5-di-tert-butyl-4-hydroxybenzoate 1... 

Zinc Formation of zinc ammonium pyrrolidine dithiocarbamate complex Cathodic stripping voltammetry [619]... 

The WGS reaction is a reversible reaction that is, the WGS reaction attains equilibrium with the reverse WGS reaction. Thus, the fact that the WGS reaction is promoted by H20 (a reactant), in turn implies that the reverse WGS reaction may also be promoted by a reactant, H2 or C02. In fact, the decomposition of the surface formates produced from H2+C02 was promoted 8-10 times by gas-phase hydrogen. The WGS and reverse WGS reactions conceivably proceed on different formate sites of the ZnO surface unlike usual catalytic reaction kinetics, while the occurrence of the reactant-promoted reactions does not violate the principle of microscopic reversibility. The activation energy for the decomposition of the formates (produced from H20+CO) in vacuum is 155 kJ/mol, and the activation energy for the decomposition of the formates (produced from H2+C02) in vacuum is 171 kJ/mol. The selectivity for the decomposition of the formates produced from H20+ CO at 533 K is 74% for H20 + CO and 26% for H2+C02, while the selectivity for the decomposition of the formates produced from H2+C02 at 533 K is 71% for H2+C02 and 29% for H20+C0 as shown in Scheme 8.3. The drastic difference in selectivity is not presently understood. It is clear, however, that this should not be ascribed to the difference of the bonding feature in the zinc formate species because v(CH), vav(OCO), and v/OCO) for both bidentate formates produced from H20+C0 and H2+C02 show nearly the same frequencies. Note that the origin (HzO+CO or H2+C02) from which the formate is produced is remembered as a main decomposition path under vacuum, while the origin is forgotten by coadsorbed H20. 

The applicability of the method is demonstrated using Zn-enriched zinc formate dihydrate Zn(00CH)2 2H20 and zinc diimidazole diacetate Zn(OOCCH3)2(C3H4N2)2 . These complexes are representatives of Zn + in an all-oxygen six-coordination sphere and in a 2-0, 2-N four-coordination sphere, respectively. 

Zinc formate (2H2O) [557-41-5] M 191.4. Crystd from water (3ml/g). 

Zn(CH02)2 (c). Berthelot9,131 measured the heat of solution of zinc formate. 

From the TPD results in Fig.l, the roles of ZnO phase on the enhancement of the rate of COz hydrogenation seem to be related with the formation of zinc formate and/or the activity of the adsorbed hydrogen on the surface of zinc oxide and/or copper. Since the activity of ZnO/SiOz has been so low when compared with those of Cu/SiOz and Cu/ZnO/SiOz, the formation of zinc formate alone is not believed to accelerate the rate of COz hydrogenation. More plausible role of ZnO phase may be the suggestion by Burch... 

Wu et al. 1998). A detailed single-crystal study of zinc acetate has indicated that although the CSA effects in this compound are small, they significantly affect the value of xq (Vosegaard et al. 1999). The 2 inequivalent octahedral Zn sites in zinc formate dihydrate have been studied by Zn NMR, which indicates that although their isotropic chemical shifts differ by only 10 ppm, their Xq values differ by more than 50% (Larsen et al. 1999). The Zn MAS NMR spectrum of K2[Zn(CN)4] has also been recorded as part of a study of potassium tetracyanometallates in which the CN ligand was partially enriched in C (Wu et al. 1995). 

DoUimore and Tonge [15] ascribed the deceleratory decomposition of zinc formate in air (0 < nr < 0.3) to an initial instantaneous and extensive nucleation of reactant crystalhte surfaces with product zinc oxide and the operation of a contracting sphere mechanism. For 0.3 < nr < 0.8 the reaction rate is almost constant, probably as a result of reactant cracking. for both processes is 67 kJ mol". During the course of reaction the yields of hydrogen and carbon monoxide increased, while that of carbon dioxide decreased. This was attributed to a decrease in the catalytic activity of the product oxide, possibly as a result of sintering. The formation of higher molecular mass products was mentioned. 

Djega-Mariadassou et al. [16] reported the occurrence of incongruent melting and the formation of an unidentified phase during the decomposition of zinc formate. Additional products identified were methane, ethane, acetone and methyl acetate. From the results of qualitative analyses, it was concluded that reaction proceeds by several routes involving radical formation, shown [bracketed] ... 

The large value for indicates the presence of other soluble Zn compounds for which a prime candidate is zinc formate (Zn(CH00)2)> a well known water-soluble compound that is formed when HCOOH reacts with Zn. If the estimated value for the CHOO concentrations is included in the expression for 4>, the following result is obtained ... 

Problem Determine whether an aqueous solution of zinc formate, Zn(HCOO)2, is acidic, basic, or neutral. 

Hirota et al., using the infrared technique described above (Section III, A, 7), measured the infrared spectrum of formic acid chemisorbed at room temperature on zinc oxide, after pumping off the excess formic acid in the gas phase and on the surface. The spectrum observed was practically identical with the spectra of zinc formate. This suggests that the formation of zinc formate on the surface plays a role in the mechanism. 

Hofmann (53) found an appreciable amount of formaldehyde (about 25%) and small amounts of methyl formate during the decomposition of zinc formate. Lithium formate produced acetone (about 20%) from lead formate, formaldehyde and methyl alcohol were formed. Pichler (127) found that during the decomposition of calcium formate, oxalate was formed. In general it appeared that the nature and the amount of the organic by-products depended largely on the reaction conditions [Hofmann (53)]. 

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