A rhodium(I) complex containing a mixed donor `P2Nʹ tridentate ligand

The reaction of 2-(diphenylphosphino)-N-[2-(diphenylphosphino)benzylidene]benzeneamine (PNCHP) with 0.5 equivalents of [{RhCl(1,5-cyclooctadiene)}2] affords the extremely, air-sensitive compound, [RhCl(PNCHP-κ3P,N,P)]. This reacts with carbon monoxide to afford [RhCl(CO)(PNCHP-κ3P,N,P)] which rearranges in dichloromethane solution to [Rh(CO)(PNCHP-κ3P,N,P)]Cl · HCl. The single crystal structure of [Rh(CO)(PNCHP-κ3P,N,P)]Cl · HCl shows the Rh to be in a square planar environment with the HCl molecule held via hydrogen bonding in the lattice. NMR experiments show the coordinated chloride in [RhCl(PNCHP-κ3P,N,P)] can be substituted with tetrahydrofuran, acetonitrile or triphenylphosphine and the complex undergoes oxidative addition with dichloromethane to yield [Rh(CH2Cl)Cl2(PNCHP-κ3P,N,P)].