The Self-assembly Study of Iso-guanosine Derivatives
Mentor Information
Xiadong Michael Shi (Chemistry)
Description
Self-assembly is the spontaneous organization of molecules through non-covalent interactions resulting in a well-defined structure with lower free energy. Guanosine and iso-guanosine derivatives can self-associate into cyclo-polymers. The H-bonding angle of Guanosine is 90o, compared to iso-guanosine which has a bonding angle of 108o. Upon cyclization, Guanosine and iso-guanosine can self-associate in the presence of cation through ion-dipole interaction. Previous experiments of guanosine derivatives self-assembly resulted in G quartet and iso-guanosine derivatives self-assembly resulted in pentaplexes. This experiment was performed to see the self-assembly differences between the iso-guanosine and the deoxy iso-guanosine. Moreover, multiple cations sources were used to examine cations selectivity of the self- assembly. Four different salts, CsCl, NaCl, KCl, BaCl2, and SrCl2, were used each time to react the deoxy iso-guanosine derivative with sodium picrate using water and CDCl3 as solvents. The product was then extracted with water. The results of self-assembly were confirmed by 1H NMR. The 1H NMR spectra analysis of the deoxy iso-guanosine derivative self- assembly showed a formation of pentaplexes. The self-assembly resulted in two stacks of the cyclo-pentamers with one cation from the salt interacting in between through ion-dipole interactions. The product was highly selective toward Cs2+ cation. Further research can be done to investigate other derivatives of guanosine and iso-guanosine self-assembly. The product selectivity toward Cs gives a potential application in the cleaning of radioactive wastes by binding to the fission product Cs.
The Self-assembly Study of Iso-guanosine Derivatives
Self-assembly is the spontaneous organization of molecules through non-covalent interactions resulting in a well-defined structure with lower free energy. Guanosine and iso-guanosine derivatives can self-associate into cyclo-polymers. The H-bonding angle of Guanosine is 90o, compared to iso-guanosine which has a bonding angle of 108o. Upon cyclization, Guanosine and iso-guanosine can self-associate in the presence of cation through ion-dipole interaction. Previous experiments of guanosine derivatives self-assembly resulted in G quartet and iso-guanosine derivatives self-assembly resulted in pentaplexes. This experiment was performed to see the self-assembly differences between the iso-guanosine and the deoxy iso-guanosine. Moreover, multiple cations sources were used to examine cations selectivity of the self- assembly. Four different salts, CsCl, NaCl, KCl, BaCl2, and SrCl2, were used each time to react the deoxy iso-guanosine derivative with sodium picrate using water and CDCl3 as solvents. The product was then extracted with water. The results of self-assembly were confirmed by 1H NMR. The 1H NMR spectra analysis of the deoxy iso-guanosine derivative self- assembly showed a formation of pentaplexes. The self-assembly resulted in two stacks of the cyclo-pentamers with one cation from the salt interacting in between through ion-dipole interactions. The product was highly selective toward Cs2+ cation. Further research can be done to investigate other derivatives of guanosine and iso-guanosine self-assembly. The product selectivity toward Cs gives a potential application in the cleaning of radioactive wastes by binding to the fission product Cs.
