Not all nitrogen atoms are equal: contribution of peripheral versus internal amines to the observed reactivity and capture properties of melamine dendrons on SBA-15.

The role of different nitrogen atoms in melamine dendrons tethered to SBA-15 is elucidated. For the nitroaldol (Henry) reaction all nitrogen atoms of the capping group participate in the reaction. For metal binding, uptake correlates with the diamine content indicating interior amines are accessible. Carbon dioxide uptake properties are dictated by the presence of the peripheral amines with little interior contribution. The results show that different nitrogen atoms contribute to different processes including catalysis, metal sequestration, and gas separations.