1,4-Diiodotetrafluorobenzene 3,5-di-(pyridin-4-yl)-1,2,4-thiadiazole <1/1>
, Anna Pintus 1, Vito Lippolis 1, Francesco Isaia 1, Alexandra M. Z. Slawin 3, Cameron L. Carpenter-Warren 3, John Derek Woollins 4 and Maria Carla Aragoni 1,*Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe present Short Note reports on a new halogen-bonded cocrystal obtained from a dipyridyl-thiadiazole derivative and 1,4-diiodotetrafluorobenzene. The crystal structure of the cocrystal is determined by single-crystal X-ray diffraction and also characterized by FT-IR spectra. The structural work is performed with high level of accuracy and the results are clearly presented.
My only concern is the description of the present halogen-bonded cocrystal as a ‘charge-transfer’ adduct. According to Politzer’s studies, halogen bond is normally described as an electrostatic interaction, though Valence Bond calculations by Shaik and coworkers have demonstrated that charge-transfer contributions can be relevant particularly for strong halogen bonds. This should not the case for the present cocrystal, as appears from the reported N…I distances.
Minor remarks:
1) Literature on halogen bond is totally lacking. Some pioneering works on this interaction and its use to create self-assembled supramolecular architectures, particularly those based on the classical dipyridyl scaffold, should be mentioned.
2) The formation of the present cocrystal cannot be described as a reaction.
3) Line 79: in the formula of compound 1 L2 should be L1.
4) Line 93: the CSD version should be specified.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
