Coordination and activation of the BF molecule.

No CO: Fluoroborylene (BF), isoelectronic with CO and N(2), can be trapped by a transition metal. The structurally characterized complex [{CpRu(CO)(2)}(2)(mu-BF)] contains an unsupported bridging BF ligand, which is unprecedented in the structural chemistry of CO. With AlCl(3) , metal-bound CO coordinates through the O atom without bond rupture, while the more polar and less pi-bonded BF ligand is heterolytically cleaved (see picture).