Formic acid, atmosphere

Anhydrous, monomeric formaldehyde is not available commercially. The pure, dry gas is relatively stable at 80—100°C but slowly polymerizes at lower temperatures. Traces of polar impurities such as acids, alkahes, and water greatly accelerate the polymerization. When Hquid formaldehyde is warmed to room temperature in a sealed ampul, it polymerizes rapidly with evolution of heat (63 kj /mol or 15.05 kcal/mol). Uncatalyzed decomposition is very slow below 300°C extrapolation of kinetic data (32) to 400°C indicates that the rate of decomposition is ca 0.44%/min at 101 kPa (1 atm). The main products ate CO and H2. Metals such as platinum (33), copper (34), and chromia and alumina (35) also catalyze the formation of methanol, methyl formate, formic acid, carbon dioxide, and methane. Trace levels of formaldehyde found in urban atmospheres are readily photo-oxidized to carbon dioxide the half-life ranges from 35—50 minutes (36). 

In contrast to the silver process, all of the formaldehyde is made by the exothermic reaction (eq. 23) at essentially atmospheric pressure and at 300—400°C. By proper temperature control, a methanol conversion greater than 99% can be maintained. By-products are carbon monoxide and dimethyl ether, in addition to small amounts of carbon dioxide and formic acid. Overall plant yields are 88—92%. 

At room temperature and atmospheric pressure, 95% of the vapor consists of dimers (13). The properties of the vapor deviate considerably from ideal gas behavior because of the dimeri2ation. In the soHd state, formic acid forms infinite chains consisting of monomers linked by hydrogen bonds (14) ... 

Nylon-11. Nylon-11 [25035-04-5] made by the polycondensation of 11-aminoundecanoic acid [2432-99-7] was first prepared by Carothers in 1935 but was first produced commercially in 1955 in France under the trade name Kilsan (167) Kilsan is a registered trademark of Elf Atochem Company. The polymer is prepared in a continuous process using phosphoric or hypophosphoric acid as a catalyst under inert atmosphere at ambient pressure. The total extractable content is low (0.5%) compared to nylon-6 (168). The polymer is hydrophobic, with a low melt point (T = 190° C), and has excellent electrical insulating properties. The effect of formic acid on the swelling behavior of nylon-11 has been studied (169), and such a treatment is claimed to produce a hard elastic fiber (170). 

The reaction conditions are approximately 100-120°C and 15-25 atmospheres. The oxidation step is noncatalytic and occurs at approximately 200°C and 60 atmospheres. An acetic acid yield of 58% could he obtained. By-products are formic acid (6%), higher boiling compounds (3%), and carbon oxides (28%). Figure 9-1 shows the Bayer AG two-step process for producing acetic acid from n-butenes. ... 

Cathodic reduction is the most promising approach to the removal of carbon dioxide from a closed atmosphere. Methods developed so far provide for electrode materials, electrolytes, and electrolysis conditions where CO2 can be reduced to hquid organic products of low molecular weight such as formic acid. More complex systems are required to regenerate foodstuffs from the rejects of human vital activities during... 

The parent hexathiaadamantane (185) is obtained preparatively when a solution of formic acid and hydrochloric acid in nitrobenzene is allowed to stand for several weeks in a hydrogen sulfide atmosphere the product which separated is almost insoluble in all common solvents and purification presents a problem. Only large volumes of dimethyl sulfoxide at reflux serve for recrystallization.224 The reaction of thioacetic acid with formic acid in the presence of zinc chloride gives tetramethyl-(186), monomethyl-, dimethyl-and trimethylhexathiaadamantane derivatives (187).225 Other variations include the reaction of thioacetic acid with a /i-diketone,226 and the use of boron trifluoride227 or aluminum chloride as a catalyst.228... 

There is considerable interest in the role of formic acid and other volatile fatty acids in the early diagnosis of organic matter in lacustrine and marine sediments. Formic acid is an important fermentation product or substrate for many aerobic and anaerobic bacteria and for some yeasts, hi the atmosphere, formic acid is an important product in the photochemical oxidation of organic matter. 

Alternatively, dissolve 10 g N,N-diethyl-N —o-nitrophenyl-ethyl-enediamine in 100 ml ethanol. Add Raney-Ni and 5 atmospheres hydrogen and hydrogenate one hour. Filter, evaporate in vacuum and reflux the oil forty minutes with 100 ml 4N HCI and 20 ml 87% formic acid. Basify with NH4OH extract four times withCHCI3 and evaporate in vacuum to get the DET analog (recrystallize-water). 

Dimethyl-2-oxazoline is commercially available from Columbia Organic Chemicals, 912 Drake Street, Columbia, South Carolina, or may be prepared as follows. In a 250-ml., three-necked flask is placed 89.14 g. (1.0 mole) of 2-amino-2-methyl-l-propanol, and the flask is cooled in an ice bath. The amine is carefully neutralized with 52.3 g. (1.0 mole) of 90.6% formic acid over a 1-hour period. A magnetic stirring bar is added, the flask is fitted with a short path distillation head, and the reaction mixture is placed in a silicon oil bath which is rapidly heated to 220-250°. The azeotropic mixture of water and oxazoline distills over a period of 2-4 hours and is collected in an ioe-cooled flask containing ether. The aqueous layer is separated, saturated with sodium chloride, and extracted with three 50-ml. portions of ether. The combined ethereal extracts are dried over potassium carbonate, filtered to remove the drying agent, and the ether is removed at 35-40° at atmospheric pressure. The 4,4-dimethyl-2-oxazoline is collected as the temperature rises above 85°. The yield is 56.7-62.7 g. (57—63%) of a colorless mobile liquid, b.p. 99-100° (758 mm. Hg). 

Neto and co-workers examined the ex situ Pt L3 EXAFS for a series of PtRu catalyst powders in air of varying nominal composition from 90 10 through to 60 40 atom %. The catalysts were prepared using a formic acid reduction method developed by the authors which resulted in very poorly alloyed particles, even after heat treatment to 300 °C under a hydrogen atmosphere. Unfortunately, the authors were not able to obtain Ru K edge data to identify the local structure of the Ru in their catalysts. 

Photolytic. Photolysis products include carbon monoxide, ethylene, free radicals, and a polymer (Calvert and Pitts, 1966). Anticipated products from the reaction of acrolein with ozone or OH radicals in the atmosphere are glyoxal, formaldehyde, formic acid, and carbon dioxide (Cupitt,... 

Titanium dioxide suspended in an aqueous solution and irradiated with UV light X = 365 nm) converted benzene to carbon dioxide at a significant rate (Matthews, 1986). Irradiation of benzene in an aqueous solution yields mucondialdehyde. Photolysis of benzene vapor at 1849-2000 A yields ethylene, hydrogen, methane, ethane, toluene, and a polymer resembling cuprene. Other photolysis products reported under different conditions include fulvene, acetylene, substituted trienes (Howard, 1990), phenol, 2-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol, 2,6-dinitro-phenol, nitrobenzene, formic acid, and peroxyacetyl nitrate (Calvert and Pitts, 1966). Under atmospheric conditions, the gas-phase reaction with OH radicals and nitrogen oxides resulted in the formation of phenol and nitrobenzene (Atkinson, 1990). Schwarz and Wasik (1976) reported a fluorescence quantum yield of 5.3 x 10" for benzene in water. 

Photolytic. Experimentally determined rate constants for the reaction of formic acid with OH radicals in the atmosphere and aqueous solution were 3.7 x lO" and 2.2 x lO" cmVmole-cule-sec, respectively (Dagaut et al, 1988). 

Photolytic. Irradiation of vinyl chloride in the presence of nitrogen dioxide for 160 min produced formic acid, HCl, carbon monoxide, formaldehyde, ozone, and trace amounts of formyl chloride and nitric acid. In the presence of ozone, however, vinyl chloride photooxidized to carbon monoxide, formaldehyde, formic acid, and small amounts of HCl (Gay et al, 1976). Reported photooxidation products in the troposphere include hydrogen chloride and/or formyl chloride (U.S. EPA, 1985). In the presence of moisture, formyl chloride will decompose to carbon monoxide and HCl (Morrison and Boyd, 1971). Vinyl chloride reacts rapidly with OH radicals in the atmosphere. Based on a reaction rate of 6.6 x lO" cmVmolecule-sec, the estimated half-life for this reaction at 299 K is 1.5 d (Perry et al., 1977). Vinyl chloride reacts also with ozone and NO3 in the gas-phase. Sanhueza et al. (1976) reported a rate constant of 6.5 x 10 cmVmolecule-sec for the reaction with OH radicals in air at 295 K. Atkinson et al. (1988) reported a rate constant of 4.45 X 10cmVmolecule-sec for the reaction with NO3 radicals in air at 298 K. 

Notes AA, acetic acid AAc, ammoniuin acetate ACN, acetonitrile AH, airnnonium hydroxide FA, formic acid MeOH, methanol TFA, trifluoroacetic acid THF, Tetrahydrofuran APCI, atmospheric pressure chemical ionization APPI, atmospheric pressure photoionization ESI, electrospray ionization IS, ion spray IT, ion trap Q, single quadrupole QqQ, triple quadrupole TOF, time of flight. 

Grosjean, D., Formic Acid and Acetic Acid Emissions, Atmospheric Formation, and Dry Deposition at Two Southern California Locations, Atmos. Environ., 26A, 3279-3286(1992). 

Carboxylic acids The smallest carboxylic acid, formic acid, can be measured using infrared spectroscopy (Table 11.2), since it has characteristic absorption bands. As discussed earlier and seen in Fig. 11.33b, mass spectrometry with chemical ionization using SiF5 also revealed HCOOH in an indoor environment (Huey et al., 1998). However, since the sensitivity in these initial studies was about two orders of magnitude less than that for HN03, the detection limit may be about the same as that for FTIR and TDLS. Formic and acetic acids have been monitored continuously from aircraft (Chapman et al., 1995) and their surface flux determined by eddy correlation (Shaw et al., 1998) using atmospheric pressure ionization mass spectrometry. Detection limits are about 30 ppt. 

Collection. Formic acid in diluted (1 10) diesel exhaust or mine air was collected by drawing the sample atmosphere through two fritted bubblers (10) in series, each containing 15 mL of 10 3 M Na2C03. A flow rate of 1.0 liter per minute and collection time of 60 minutes for diluted diesel exhaust or 240 minutes for mine air was used. A 37 mm glass fiber filter (Gelman Type A/E) was placed before the bubblers to remove particulates. 

The precision of the ICE method was determined by analyzing six replicates of two standard solutions containing strong acids (i.e., H2S0i ) and several weak acids (i.e., formic acid, acetic acid and carbonic acid). Carbonic acid is present as a result of the use of Na2C03 n the standard solution matrix (as in the collection medium) and dissolution of atmospheric carbon dioxide (Figure 4). At formic acid concentrations of 5.0 and 10 mg/L, the measured mean concentrations (Table III) were 5.08 and... 

The acid-catalyzed hydrocarboxylation of olefins (the Koch reaction) can be performed in a number of ways.565 In one method, the olefin is treated with carbon monoxide and water at 100 to 350°C and 500 to 1000 atm pressure with a mineral-acid catalyst. However, the reaction can also be performed under milder conditions. If the olefin is first treated with CO and catalyst and then water added, the reaction can be accomplished at 0 to 50°C and 1 to 100 atm. If formic acid is used as the source of both the CO and the water, the reaction can be carried out at room temperature and atmospheric pressure.566 The formic acid procedure is called the Koch-Haaf reaction (the Koch-Haaf reaction can also be applied to alcohols, see 0-103). Nearly all olefins can be hydrocarboxylated by one or more of these procedures. However, conjugated dienes are polymerized instead. 

A 25-mL round-bottom flask was charged with l-[Val-Thr(Bzl)-Val-Thr(Bzl)-DMEDA]2 (180 mg, 102 pmol) dissolved in MeOH (2 mL) and formic acid (approx. 3 mL). The flask was flushed with N2 and 10% Pd/C (102 mg) was added. The N2 atmosphere was then replaced with an atmosphere of H2. The reaction was monitored by C18 RP-HPLC. After 4-5 h, the MeOH was removed under reduced pressure and the thick, heterogeneous soln was diluted with H20 (10 mL). The pH of the soln was adjusted to approx. 7 and the catalyst filtered using a 0.22-pm acetate membrane. The soln was analyzed by analytical C18 RP-HPLC and purified using semi-preparative C18 RP-HPLC. The MeCN in the column fractions was removed under reduced pressure and the sample lyophilized to afford the side-chain deprotected peptidomimetic 3 yield 58 mg (45%) ESI-MS rn/z- [M+H]+ calcd. 1253.5 found 1254.0. 

Atmospheric oxidation of methane, 81 dimethyl peroxide from, 81 formaldehyde from, 81 formic acid from, 81... 

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