Ion Channel-like Crystallographic Signatures in Modified Guanine–Potassium/Sodium Interactions

This communication describes crystallographic details
of structures
reminiscent of ion channels, formed from regioisomeric N7 and N9 guanine-carboxylate
conjugates with potassium/sodium ions and their subsequent STM observations
on Au(111) surface. Ion channel-like crystal structures were obtained
with the observation of a notable shift in metal ion coordination
from carbonyl to carboxylate oxygen. These results are expected to
provide insight into competing sites for modified guanine–metal
coordination, an entry into guanine-based ion channels and a route
toward guanine-functionalized surfaces.