Crystal engineering of 5,5′-bisdiazo-dipyrromethane with halogenπ synthonsCCDC reference numbers 724476–724478. For crystallographic data in CIF or other electronic format see DOI: 10.1039/b905568a.

Chlorine, bromine and iodine substituted derivatives of 5,5′-bisdiazo-dipyrromethane have been synthesized and their crystal structures were studied by X-ray crystallography. In the three structures, the 5,5′-bisdiazo-dipyrromethanes form interlocked dimers through quadruple N–HN hydrogen bonds. The halogenπ synthons also provide a significant contribution to the resulting supramolecular motifs. [ABSTRACT FROM AUTHOR]