1,3‐Diphosphacyclobutadienecobalt(<scp>I</scp>) Complexes from Phosphaalkynes

Abstract

The first diphosphacyclobutadiene with three-coordinate phosphorus could be stabilized as cobalt-complexed compound 3 by dimerization of the phosphaalkyne 1 in the presence of the cobalt complex 2. If 2 is present in excess, di- and tri-nuclear cobalt complexes are also formed, by coordination of the fragment [(C5H5)(C2H4)Co] to the P atoms of 3.