Crystal structure of the 1-aminocyclopropanecarboxylate–pyridoxal Schiff base complex of copper(II): a model for a Schiff base intermediate in ethylene biosynthesis

Abstract

X-Ray structural analysis of the copper(II) complex of the Schiff base formed between 1-aminocyclopropanecarboxylate, a precursor of the plant hormone ethylene, and pyridoxal, [Cu(C₁₂H₁₃N₂O₄)]·(NO₃)·H₂O, shows that the copper atom is square-pyramidally co-ordinated by the tetradentate Schiff base, the equatorial plane being defined by the imino nitrogen, the phenolic and the carboxylate oxygens, and a water molecule, and the axial position being occupied by the hydroxymethyl oxygen of a neighbouring molecule, thus forming a one-dimensional polymer.