Formic Acid and Formates

The kinetics of the catalytic decomposition of formic acid on sodium tungsten bronzes Naj,W03, with x in the range 0.11—0.85, and on tungstic oxide have been investigated manometrically in a static system at 150— 250 °C with acid pressures of 25—30 Torr. The decomposition products were CO2, CO, H2O, and Hg, the mole ratios C02 CO and H2 C02 being determined mass-spectrometrically. 

The acid dissociation constant of the carboxyl radical CO2H (pK = 1.4) has been determined from an analysis of the results of a pulse-radiolysis study of aqueous solutions of formic acid and the formate anion.  

The kinetics of oxidation of the formate anion by aqueous bromine have been investigated by a potentiometric method the product of the reaction is COg. The influence of y-irradiation on the kinetics of thermal decomposition of lead formate has been assessed. The decomposition of the salt  

Two structural investigations of lithium formate monohydrate have been undertaken in an attempt to fix the positions of the water protons. The 

In a similar investigation the n.m.r. spectra of strontium formate [ Flgldihydrate have been recorded at 29.5 °C in an attempt to check which of the two previously published structures of Sr(HC00)2,2H20 is correct. Unfortunately, the results are not consistent with the X-ray analysis of Galign6 and Falgueirettes, and only partially in agreement with that of Osaki. If the latter structure is correct then the first formate ion appears to be planar whereas the second one is bent out of plane by approximately 22°. 

Analysis of the results obtained in the photoionization of HC02H has led to a value of AHe(HCO,g) = 10.2 kcal mol1162 (c/. 9.9kcal mol-1 derived from the photoionization of H2CO). 

A kinetic study of the reaction of formate and peroxydisulphate in aqueous solution [reaction (35)] has been made.163 A mechanism has been proposed based on a chain reaction involving SO , OH, and C02 radicals. 

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Formic acid and formate salts are also effective reducing agents for 7r-allylpalladium complexes (equation 105).301-303... 

Formaldehyde and its Substituted Derivatives.—Formaldehyde, Carbonyl Halides, etc. Despite the general decrease in the number of publications in this field, the high proportion describing the spectroscopic properties of these molecules has been maintained these, together with the corresponding publications for formic acid and formates, are collected in Table 9. The... 

Some oxidoreductases require nicotine adenine dinucleotide (NADH) as a cofactor.146 To use them in organic synthesis, as in the reduction of a ketone to an alcohol, it is necessary to have an efficient system to continuously regenerate them. A common way is to include in the same reaction formic acid and formate dehydrogenase, the byproduct being carbon dioxide.147 The regeneration of the cofactor can also be done electrochemically with or without the addition of a hydrogenase.148 The use of whole organisms eliminates this need. 

The emergency room treatment for methanol poisoning is to inject ethanol intravenously to tie up the alcohol dehydrogenase enzyme so that methanol will not be converted to formic acid and formate, which causes blindness. The goal of this open-ended problem is to build on the physiological-based model for ethanol metabolism to predict the ethanol injection rate for methanol poisoning. One can find a start on this problem by reading problem P7-25c. 

Several of the most common hydrogen donors, such as formic acid and formates, ascorbic acid, EDTA or 2-propanol are well or at least sufficiently soluble in water. In addition, H20 itself can serve as a source of hydrogen. Frequently, hydrogenation of unsaturated substrates is achieved by using C0/H20 mixtures such reactions are discussed in 3.8. As written in eq. (3.11) the hydrogen transfer reaction is often reversible, an obvious example being the reduction of ketones using 2-propanol as donor. 

Formic acid and formates were among the most effective donors used for the reduction of olefins with [RuCl2(PPhj)j] or [RhCl(PPh3)3] catalysts in non-aqueous systems [239-241], No wonder, the water soluble analogues of these catalysts became widely used in aqueous solutions. In a series of investigations [242-245] with Ru/IPPMS and Rh/TPPMS catalysts olefins (such as 1-heptene) were hydrogenated in mixtures of HCOOH/HCOONa. Crotonaldehyde was selectively reduced to butyraldehyde by the [RhCl(TPPMS)3] catalyst [245], It was also established that (unfiltered) ultraviolet irradiation accelerated the reactions [245],... 

Except for 3-bromoindole, it is necessary to proceed via the indoline, because treatment of indole with 1,1-dimethyIpropargyl chloride (31) in the presence of base leads to product mixtures resulting from reaction of in situ formed dimethyl-vinylidene carbene. Sheu and co-workers isolated the three products 32, 33 and 34 on reaction of indole-3-carbaldehyde (30) (Scheme 7) [53]. In the main reaction, indole C3 attacks at dimethylvinylidene carbene forming a vinyl anion, which is protonated to give the 3-allenylindolenine. Hydroxide then attacks the carbal-dehyde moiety with loss of formic acid and formation of a 3-allenylindole. Addition of a second equivalent of indole-3-carbaldehyde (30) affords 32 and 33. 

Generation of CO2 by VUV irradiation of aqueous solutions requires efficient scavenging by formic acid and formate ions [reactions (R2-R5)] of HO and H which are primarily formed by photolysis. Under the chosen experimental conditions, Caq are efficiently quenched by HsO". Other reactions of H, HO and e aq. such as recombination reactions leading to H2 and H2O2, respectively, and with the substituted benzenes should be negligible. 

Formic acid and formates are excellent sources of PdH species in transfer hydrogenation/hydrogenolysis. 

Reduction. A variety of metal hydride reducing agents can be employed to reduce jr-allylpalladium dimers. These include sodium borohydride, sodium cyanoborohydride, lithium triethylborohydride, lithium aluminum hydride, lithium tri-ferf-butoxyaluminum hydride, polymethylhydrosiloxane, and RsSiH (eq Formic acids and formate salts also reduce... 

After finishing her RiD, Michele Siggel came to Berkeley and did further calculations of formic acid and formate ion, ethanol and ethoxide ion. This work showed that the oxygen atoms also have high negative charges that do not differ much in these different functional groups. That is, deprotonation of... 

Palladium is the best catalyst for electrochemical oxidation of formic acid and formate ion [78, 224],... 

Fundamental Frequencies of Formic Acids and Formate Ions in cm. ... 

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