Circular arrangement of nucleoamphiphile containing azobenzene by using base pairing with cyclic oligonucleotide template at the air–water interface

In order to attempt the circular arrangement of chromophores directed by base pairing with cyclic oligonucleotides as template at the air–water interface, the monolayers of an amphiphilic adenine having azobenzene (AzoAde) were prepared on aqueous linear oligothymidylic acids (LinT6, LinT8, and LinT10) and corresponding cyclic oligothymidylic acids (CycT6, CycT8, and CycT10) solutions. The aggregation structures of AzoAde in the monolayers were investigated by in-situ UV–Vis reflection absorption spectroscopy. The linear oligothymidylic acids and CycT10 provided J aggregation of the azobenzene moiety in the formed monolayers even without compression of the monolayers, whereas the azobenzene moiety in the monolayers formed on CycT6 and CycT8 was isolated. Π–A isotherms on the CycT6 and CycT8 subphases were different from those on other oligothymidylic acid subphases, indicating that particular arrangement of AzoAde was attained in the monolayers complexed with CycT6 and CycT8. It was, therefore, suggested that the azobenzene chromophore in the monolayer could be circularly arranged on the CycT6 and CycT8 templates at the air–water interface.