Functional groups distinguishing

What functional group distinguishes each of the following hydrocarbon derivatives ... 

Mechanism of action. Formaldehyde mode of action has been extensively studied and is due to its ability to react with several different amino acids. It will react with those amino acids containing sulfhydryl (cysteine), hydroxyl (serine), and amine (lysine, arginine) groups. It is also unique in that it may also react with the purine and pyrimidine groups of both DNA and RNA. The varied nature of formaldehyde s mode of reactivity with all of these functional groups distinguishes it from other aldehydes such as acrolein and glutaraldehyde. 

Look at the IR spectra of hexane, 1-hexene, and 1-hexyne in Figure 12.14 to see an example of how IR spectroscopy can be used. Although all three IR spectra contain many peaks, there are characteristic absorptions of the C=C and C=C functional groups that allow the three compounds to be distinguished. Thus, 1-hexene shows a characteristic C=C absorption at 1660 cm"1 and a vinylic =C—H absorption at 3100 cm"1, whereas 1-hexyne has a C=C absorption at 2100 cm"1 and a terminal alkyne =C-H absorption at 3300 cm"1. 

As each functional group is discussed in future chapters, the spectroscopic properties of that group will be described. For the present, we ll point out some distinguishing features of the hydrocarbon functional groups already studied and briefly preview some other common functional groups. We should also point out, however, that in addition to interpreting absorptions that ore present in an IR spectrum, it s also possible to get structural information by noticing which absorptions are not present. If the spectrum of a compound has no absorptions at 3300 and 2150 cm-1, the compound is not a terminal alkyne if the spectrum has no absorption near 3400 cm -, the compound Is not an alcohol and so on. 

This expression has the same form as Eqs. (6-81) and (6-84). Here, of course, the substrate is not protonated to an appreciable extent. With other suitable experiments and some luck, the steady-state situation can be distinguished from substrate titration. For example, is the pKa value deduced under the assumption of a titration reasonable for the molecule in question That is, is it reasonable for one of the functional groups of A to have a pKa near the pH of the bend Can one detect significant amounts of two species, AH+ and A, at a pH near the presumed pKal Can one modify the substrate, eliminating the site of protonation If so, and if a titration mechanism operates, then (as the reader should show) the pH profile should become linear. Obviously, were substrate titration and a steady-state intermediate situation to coexist in the same system, a more complicated but not intractable situation would result. 

The naming system in organic chemistry includes munbers used to specify the positions of functional groups (propan-l-ol, propan-2-ol, hexa-2-ene, 1, 2-dichoroethane etc). New symbols such as p-, o-, m- (para-, ortho-, meta-), a-, P-, E/Z, D-/L-, (- -)/(-), R-/S- etc. are introduced to distinguish isomers of more complex molecitlar structures. 

When making theoretical considerations of polycondensation processes it is necessary to distinguish chemically identical functional groups if they differ in reactivity. Examples are primary and secondary hydroxyls in a molecule of glycerine, SA2j A2, which belong to kinetically distinct types Ax and A2. 

Relationships (61)—(63) admit simple probabilistic interpretation in terms of the branching process. To the reproducing particles of this process the reacted functional groups correspond distinguished by color i and label r. Integer i characterizes the type S, of monomeric unit to which a given group was attached at the moment r of its formation. 

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