A half cleaved zirconacyclopentadiene

When the sterically strained bicyclic zirconacyclopentadiene 2 is reacted with two equivalents of iodine in the presence of copper(I) chloride, the diiodinated product 4 forms in the range of 10 h. However, when reacted only for 2 h, the monoiodinated zirconium complex 3 is isolated. 3 shows an unexpected stability towards hydrolysis and oxidation. The molecular structure of complex 3 has been determined by X-ray structural analysis.