X-ray Diffraction and NMR Studies on a Series of Binap-Based Ru(II) Hydroxyphosphine π-Arene Complexes

A series of new Ru(II) arene phosphine complexes derived from Binap have been prepared. Specifically, reaction of Ru(OAc)2(Binap) with 3,5-(CF3)2C6H3)4B (BArF)·H(OEt2)2, is shown to afford new mono- and dinuclear Ru(II) hydroxyphosphine π-arene complexes via a series of P−C bond cleavage reactions. The dinuclear Ru(II) π-arene complexes contain bridging P(O)(OH)2 ligands. Crystal structures of five new complexes are reported and suggest an η4-arene rather than an η6-arene coordination mode. However, in solution, their 13C NMR data are more consistent with a strongly distorted η6-coordination mode. PGSE 1H and 19F diffusion measurements on the dinuclear complexes suggest hydrogen bonding of the triflate anion and ion-pairing of the BArF- anion.