In this paper synthetic molecular clefts with functional groups complementary to adenines, diketopiperazines, and barbiturates are described. Lactams and imides are compared for hydrogen-bonding affinites toward each other and to the heterocycles mentioned above. Titrations in CDC13 using NMR show association constants vary by factors of 104 for adenines, l02 for diketopiperazines, and 10 for barbiturates with the new receptors. Enantioselective recognition of cyc/o-L-Leu-Leu is observed, corresponding to ΔΔG = 2.7 kcal/mol. The relative strengths of hydrogen-bonding arrays are interpreted in terms of secondary interactions such as defined in the following paper in this issue by Jorgensen and Severance.
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry