Noncovalent interactions in the design of bis-azo dyes

A series of new (1E,1 ' E)-2,2 '-((perfluoro-1,4-phenylene)bis(2,2-dichloroethene-1,1-diyl))bis(1-(para-substituted phenyl)diazenes) have been synthesized via CuCl catalyzed olefination of the corresponding Schiff bases with CCl4 in the presence of tetramethylethylenediamine (TMEDA) in DMSO. ClMIDLINE HORIZONTAL ELLIPSISO and ClMIDLINE HORIZONTAL ELLIPSISF types of halogen bonds were found in these bis-azo dyes, which depend on the electron-donating or -accepting properties of the para-substituent (-OCH3, -CH3, -H, -F) of the azoaromatic ring. DFT calculations demonstrate that noncovalent interactions play a significant role in the stabilization of the intermolecular networks of the structures under study.