A Porphyrin as a Binucleating Ligand: Preparation and Crystal Structure of a Porphyrin Complex Containing a Coordinated B2 O2 Ring.

Abstract

A new coordination mode for the porphyrin ligand is found in [B2 O2 (BCl3 )2 (tpClpp)] (tpClpp=dianion of 5,10,15,20-tetra-p-chlorophenylporphyrin; the p-chlorophenyl groups are omitted for clarity in the picture shown on the right). This complex contains a four-membered B2 O2 ring in the cavity of the ligand. The two boron atoms are coplanar with the porphyrin molecule, which undergoes an elongation along the B⋅⋅⋅B axis to accomodate the unusual guest.