Covalent and Selective Labeling of Proteins with Heavy Metals. Synthesis, X-ray Structure, and Reactivity Studies of N-Succinimidyl and N-Sulfosuccinimidyl Ester Organotungsten Complexes

New functionally substituted η5-cyclopentadienyl and 2-oxaallyl (η1-enolate) tungsten complexes bearing an N-succinimidyl or an N-sulfosuccinimidyl ester have been prepared and fully characterized. The molecular structures of [η5-((succinimidooxy)carbonyl)cyclopentadienyl]methyltricarbonyltungsten(II) (2) and [η5-((succinimidooxy)carbonyl)cyclopentadienyl]iodotricarbonyltungsten(II) (5) were solved by X-ray crystallography. The reactivity of …