The self-assembly of a lipophilic guanosine nucleoside into polymeric columnar aggregates: The nucleoside structure contains sufficient information to drive the process towards a strikingly regular polymer

Lipophilic guanosine derivatives act as self-assembled ionophores. In the p resence of alkali metal ions in organic solvents, these G derivatives can f orm tubular polymeric structures. The molecular aggregates formed by 3',5'- didecanoyl-2'-deoxyguanosine (1) have been characterised by SANS and NMR sp ectroscopy. The polymer is structured as a pile of stacked G quartets held together by the alkali metal ions that occupy the column's central channel. The deoxyribose moieties, with their alkyl substituents, surround the stac ked G quartets. and the nucleoside's long-chain alkyl tails are in intimate contact With the organic solvent. In this polymeric structure, there is an amazing regularity in the rotamers around the glycosidic bond within each C quartet and in the repeat sequence of the G quartets along the columns. I n hydrocarbon solvents, these columnar aggregates form lyomesophases of the cholesteric and hexagonal types.