A weak η1 π-bonding mode for Ruarene complexes. Nitrile, isonitrile and phosphine derivatives of Ruphosphinoarene chelating complexes

The synthesis of new derivatives based on a Ru(Ph2Parene)(POHPh2) fragment, possessing nitrile, isonitrile and phosphine ligands, are reported. The new nitrile compounds, e.g. [Ru(H2O)(RCN)2(Ph2Pη1arene)(POHPh2)](OTf)2, R=Me, p-tolyl, reveal a new and unexpected weak η1 π-bonding mode from a single CHbiaryl arene carbon to the ruthenium atom, as demonstrated by 13C-NMR. The solid-state structures for two examples are reported. In one complex a new RuPOCNH five-membered ring is formed due to the POH oxygen attack on the complexed p-tolyl nitrile.