Synthesis, structure and dynamics of methoxynaphthalene-substituted phospha-ruthenocenes and -ferrocenes

The syntheses of potassium 2-(2′-methoxynaphth-1′-yl)-3,4-dimethyl-5-phenylphospholide 4 and η5-pentamethylcyclopentadienyl{η5-2-(2′-methoxynaphth-1′-yl)-3,4-dimethyl-5-phenylphospholyl}-ruthenium(II) 5 and -iron(II) 6 are described. The barrier to rotation of the naphthyl group (79 kJ mol−1 and 72 kJ mol−1 in CD2Cl2 respectively) characterises 5 and 6 as potential ‘tropos’ type ligands. Coordination of 5 to [PtCl2(PEt3)] gives two cis and two trans complexes [PtCl2(PEt3)5] wherein rotation about the phospholyl–naphthyl vector is slow.