A review of papers up to 2008 dealing with all branches of chemistry of the compounds containing 2,2′-pyridine-2,6-diylbis(1H-benzimidazole) and 2,2′-pyridine-2,6-diylbis(1,3-benzothiazole) is presented. The review summarizes the preparation procedures and properties of free organic compounds, as well as their different protonated and/or deprotonated forms. A summary of complex compounds of the considered ligands is presented together with the review of the most important properties such as spectroscopic properties, structures, magnetic properties or biological and electrochemical activity. From this review the blind spots can be identified which might suggest more points of potential interest. Also missing is a promising investigation of, at present unknown, analogues.