Reaction Between 2-(2-Aminoethyl)pyridine and Acenaphthenequinone in the Presence of ZnCl2.

9-(Pyridin-2-yl)-7-[2-(pyridin-2-yl)ethyl]-7H-acenaphtho[1,2-b]pyrrole (1) was formed by a reaction of 2-(2-aminoethyl)pyridine and acenaphthenequinone in the presence of ZnCl₂. At the first step salt 1-Zn was isolated, which consists of the doubly protonated form of 9-(pyridin-2-yl)-7-(2-(pyridin-2-yl)ethyl)-7H-acenaphtho[1,2-b]pyrrole as the cation and ZnCl₄^2– as the counterion. Salt 1-Zn was further treated by K₂C₂O₄ to give unexpected compound 1. The redox properties of 1 were investigated by voltammetry. It was found that the measured potential values for reduction and oxidation peaks are correspond to acenaphthene-based ligands. Compound 1 is oxidized upon storage in air to give the corresponding 6b-hydroxy-9-(pyridin-2-yl)-7-(2-(pyridin-2-yl)ethyl)-6bH-acenaphtho[1,2-b]pyrrol-8(7H)-one (2). All newly obtained compounds were isolated and characterized by single-crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]