Methanoic acid, 288 Table

The presence of methylamine on quartz (lOl 1 stabilized the surface more as compared with those in the presence of water and methanoic acid (Table 3.4). The adsorption energy for an amine molecule was more negative than for water and methanoic acid (Table 3.5), indicating that in an equilibrium condition methylamine will adsorb preferentially on this surface by displacing water and methanoic acid molecules. Methylamine adsorption did not induce any noticeable surface reconstruction. Nitrogen of amine oriented itself at the bump distance (2.52 A with 70% of the sum of covalent radii) from the three-coordinated surface silicon, and the methyl group of the amine molecule was located away from the surface (Figure 3.10a). 

A carboxyl group is usually represented in condensed form by writing -COOH. For example, ethanoic acid can be written as CH3COOH. The simplest carboxylic acid consists of a carboxyl group bonded to a single hydrogen atom, HCOOH, shown in Table 22.9. Its formal name is methanoic acid, but it is more commonly known as formic acid. Some insects produce formic acid as a defense mechanism, as shown in Figure 22.10. 

The nomenclature for carboxylic acids follows the familiar pattern of adding the functional group name -oic acid to the named hydrocarbon chain except that the common names formic acid and acetic acid are still widely accepted. Thus, formic acid is methanoic acid, acetic acid is ethanoic acid, propionic acid is propanoic acid, and -butyric acid is butanoic acid. The CAS numbers (Chemical Abstract Service, American Chemical Society) for the carboxylic acids are listed in Table 6.1 along with the physical properties. The CAS numbers refer to the major carboxylic acid component. Refer to the Material Safety Data Sheet (MSDS) for CAS numbers of any minor impurities in the solvent. 

The adsorption energies calculated for the adsorption of methanoic acid on the minimized hydroxylated quartz surfaces are summarized in Table 3.6. The methanoic acid adsorption energy was... 

It is evident from the adsorption energies presented in Table 3.5, that except for the 0001 and 1120 surfaces, dissociative water adsorption was more energetically favorable than other adsorbate molecules. The 1020 surface was the most reactive for associative adsorption, and the preference was for methylamine, followed by methanoic acid, followed by water. The lOll and lOlI surfaces did better when hydroxylated, but for associative adsorption the preference was more toward methylamine, followed by methanoic acid, followed by water. 

Because many carboxylic acids were among the first organic compounds to be isolated and purified, a large number of common names exist (Table 20.1). Biological chemists, in particular, make frequent use of these names, so you may find yourself referring back to this list on occasion. We ll use systematic names in this book, with a few exceptions such as formic (methanoic) acid and... 

Table Vl-B-1. Rate coefficients (k = Ay. cm molecule" s ) for reaction of OH with formic acid (methanoic acid, HC(O)OH)...

Systematic names for carboxylic acids are derived by counting the number of car bons m the longest continuous chain that includes the carboxyl group and replacing the e ending of the corresponding alkane by oic acid The first three acids m Table 19 1 methanoic (1 carbon) ethanoic (2 carbons) and octadecanoic acid (18 carbons) illus trate this point When substituents are present their locations are identified by number... 

We can obtain the same phosphorane 1 2 by methano-lysis of phosphorane 5. Concerning the stereochemistry of the phosphorane double-bond, we observe that the E isomer is the more stable. The first reaction of Table 1 gives Z isomer, but only traces of benzoic acid are necessary to provoke instantaneous isomerisation of Z to E. The mechanism probably involves an addition-elimination. 

Scheme 4.16, Table 4.6). In the case of synthesis of (2/ ,35)-3-cndo-p-methylbenzy-loxycarbonyl-1,2,3,4-tetrahydro-1,4-methano-naphthalene-2-carboxylic acid (entry 1), the use of ball milling was advantageous, since in solution the starting anhydride was unreactive, whereas nnder ball-milling conditions the asymmetric anhydride opening with p-methylbenzyl alcohol proceeded well, affording hemiester with 32% enantiomeric excess in 78% yield. 

This subsection will familiarize the reader with the naniing system tor some of die more common and simple organic groups, and present the salient characteristics of these groups. The basic system of aliphatic organic nomenclature is shown in Table 4. The prefix for the name is based on the number of carbons involved and remains the. same for each type of compound described. The suffix is dctcnnined by the type of compound and is independent of the number of carbons in the molecule. Tlius. mediane. methanol, methanol (formaldehyde), and methanoic (fonnic) acid represent an alkane, an alcohol, an aldehyde, and a carboxylic acid, respectively, each with one carbon per molecule. In contrast, methanol,... 

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