In Situ Reduction of Copper(II) Forming an Unusually Air Stable Linear Complex of Copper(I) with a Fluorescent Tag

A new fluorescent ligand (φf = 0.8 in dioxane), 2-(4‘-aminophthalimidomethyl)pyridine (L), has been synthesized. A one-pot
synthesis of its copper(I) complex upon reduction of copper(II) is
achieved at room temperature. This complex, which has been
characterized by X-ray crystallography, shows a linear N−Cu−N
geometry with Cu−N bond lengths of 1.89 Å. X-ray structure reveals
weak Cu···O interactions between copper and one of the imide
oxygen atoms of the ligand framework. Additional weak Cu···O
interactions between copper and oxygen atoms of the ClO4-
counteranion are detected that lead to a zigzag polymeric chain
with alternate ClO4- and copper ions. A 2-D intermolecular
hydrogen bonding network is also observed. This complex is found
to be highly inert toward oxidation both in the solid state and in
solution.