J. Med. Chem. Perspective
I started studying halogen bonds during my Ph.D. years. I've always been wondering if there are any halogenated ligands known that bind into nucleic acids and form halogen bonds (The Question). Recently, I've analyzed known structures of nucleic acid complexes and with Oriana Tabarrini from University of Perugia we've written a story about the analyses. It's just been accepted as a Miniperspective to The Journal of Medicinal Chemistry (American Chemichal Society). By the way, the answer is No.
We analyzed all X-ray structures of nucleic acids that contain a halogen atom either on a low-molecular-weight ligand, or on a nucleobase. We found 21 halogen bonds (X-bonds) and a few dozen interactions longer than X-bonds. It turned out that none of the X-bonds involves a noncovalent ligand. The dominant interaction pattern is halogenated nucleobase...backbone oxygen. Hence it seems that the first halogen bonded nucleic acid binder still remains to be discovered.