Amides, secondary self-association

The principal IR absorptions of 3,20,23 5, and 913,18 (which compounds have been recommended for the identification of alcohols24 25 and primary or secondary amines18) and of 2-substituted saccharins (10)20,23 recorded under identical conditions appear as sets of relatively constant frequencies. For structures with an acidic hydrogen, e.g., compounds (l)16 (2), (9), self-association and complex formation is expected, but the dipolar 3-dialkylamino derivatives (5b) also tend to associate in various solvents.14 Saccharin (1) has been reported to form 1 1 complexes with purines, e.g., theophylline and caffeine, and with amides and... 

Massuda and Sandorfy carried out infrared measurements at temperatures ranging from room to liquid nitrogen temperature on solutions containing self associated secondary amines, amides or alcohols which contain hydrogen bonds of the N—H---------N, N—H--------0=C < and 0 H-------------O types. An anesthetic con-... 

Since not much information was available on the quantitative thermodynamics of hydrogen bonding involving the N—H bonds of secondary amides, Bhaskar and Rao (1967) carried out investigations on the self-association of secondary amides as well as their interaction with certain bases by infrared spectroscopy. They studied the thermodynamics of the hydrogen-bonding interaction of cis as well as irons N—H bonds of secondary amides. 

Nonheterocyclic modules 14 and 15 associate via amide donor-acceptor interactions reminiscent of those responsible, in part, for the ordered secondary sfiuctures of oligopeptides and proteins [34,35], Association of 14 and 15 is exceptionally strong in chloroform, Kassoc = 1.3 x 10 M , as indicated by isothermal microcalorimetry. Gong and coworkers have also assembled self-complementary hydrogen-bonded dimers from compounds analogous to 14 and 15 [38],... 

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