Molecular recognition in a uradinyl-functionalized stable radical

摘要

Stable radical 2-(6-uradinyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-l-oxyl(1)binds to hydrogen-bonding complement 2,6-di(propylamido)pyridine(DAP)in chloroform with K_a = 220 M~(-1)at 33 deg C;ESI-MS shows not only 1:DAP complementary dyad formation,but also 1:9DAP)_2 formation at higher concentrations of DAP.Hydrogen bonds provide some of the strongest noncovalent interactions between molecules.They also tend to be strongly directional,providing a reasonably dependable basis for predicting how a molecule or sets of molecules might assemble in solution or in crystalline arrays.Their use has become a strong theme in both biological molecular recognition work,and in materials science,because they offer a means of controlled supramolecular assembly based on molecular building blocks.