2,6‐Bis(azaindole)pyridine: reactivity with iron(III) and copper(II) salts

1‐6‐(1H‐Pyrrolo2,3‐b]pyridin‐1‐yl)pyridin‐2‐yl]‐1H‐pyrrolo2,3‐b]pyridin‐7‐ium tetrachloridoferrate(III), (C₁₉H₁₄N₅)FeCl₄], (II), and 2,6‐bis(1H‐pyrrolo2,3‐b]pyridin‐1‐yl‐κN⁷)pyridine‐κN]bis(nitrato‐κO)copper(II), Cu(NO₃)₂(C₁₉H₁₃N₅)], (III), were prepared by self‐assembly from FeCl₃·6H₂O or Cu(NO₃)₂·3H₂O and 2,6‐bis(1H‐pyrrolo2,3‐b]pyridin‐1‐yl)pyridine commonly called 2,6‐bis(azaindole)pyridine, bap], C₁₉H₁₃N₅, (I). Compound (I) crystallizes with Z′ = 2 in the P space group, with both independent molecules adopting a trans–trans conformation. Compound (II) is a salt complex with weak C—H...Cl interactions giving rise to a zigzag network with π‐stacking down the a axis. Complex (III) lies across a twofold rotation axis in the C2/c space group. The Cu^II center in (III) has an N₃O₂ trigonal–bipyramidal environment. The nitrate ligand coordinates in a monodentate fashion, while the bap ligand adopts a twisted tridentate binding mode. C—H...O interactions give rise to a ribbon motif.