Naphthylbipyrrole-Containing Amethyrin Analogue: A New Ligand for the Uranyl (UO₂²⁺) Cation

Abstract

Using naphthobipyrrole as a functional building block, a new expanded porphyrin, naphthoisoamethyrin, was prepared in 85% yield under acid-catalyzed [4 + 2] MacDonald coupling conditions. Treatment of naphthoisoamethyrin with the nonaqueous uranyl silylamide salt [UO₂[N(SiMe₃)₂]₂·2THF] yielded the corresponding uranyl complex. Upon metalation, naphthoisoamethyrin undergoes a two-electron oxidation to yield a formal 22 π-electron aromatic species, as inferred from ¹H NMR and UV-vis spectroscopy, as well as cyclic voltammetry.