Based on the recent findings that fluorinated oligonucleotides can improve down regulation of gene expression we became interested in the investigation of a fluorinated version of our bicyclo-DNA. Chimeric DNA/6´-fluoro-bicyclothymine oligonucleotides showed remarkable stabilization of duplex formation particularly with RNA as complement.
Based on the X-ray structure and NMR measurements of the monomers we hypothesize that this stabilization is due to a weak F-H-C6 electrostatic interaction.

This work was carried out in the group of Prof. Christian Leumann.

References:

• B. Dugovic, C. J. Leumann;
  "A 6'-Fluoro-Substituent in Bicyclo-DNA Increases Affinity to Complementary RNA Presumably by CF-HC Pseudohydrogen Bonds"
  J. Org. Chem., 79, 1271-1279, (2014); doi:10.1021/jo402690j.