Ru(II) COMPLEXES CONTAINING CHELATING PHOSPHINE LIGANDS. SYNTHESIS, CHARACTERIZATION, AND X-RAY CRYSTAL STRUCTURES OF DICHLOROBIS(1,2-BIS(DIPHENYLPHOSPHINO)ETHANE)Ru(II) AND THE COORDINATIVELY UNSATURATED TRIGONAL-BIPYRAMIDAL CATION, CHLOROBIS-(1,2-BIS(DIPHENYLPHOSPHINO)ETHANE)Ru(II)

Abstract

The reaction of trans-RuCl₂(dppe)₂ (1), with AgBF₄ in tetrahydrofuran leads to abstraction of one of the halide ligands to produce the trigonal-bipyrimidal complex, [RuCl(dppe)₂]BF₄ (2). Both products are characterized by ³¹P NMR spectroscopy and their crystal structures determined. For the coordinatively unsaturated trigonal-bipyramidal complex (2), we found no evidence for the presence of more than one species or fluxional behaviour at room temperature in the ³¹P NMR spectrum. This complex was found to possess a trigonal-bipyramidal geometry in the solid state. Crystals of 1 are monoclinic, space group P2₁/c with a = 23.713(4)Å, b=11.156(1)Å, c = 17.595(2)Å, β=103.23(1) and v=4531(1)ų. Convergence to conventional R values of R=0.043 and R_w = 0.042 was obtained for 416 variable parameters and 2746 reflections with I>3σ(I). Compound 2 in triclinic, P1, a=12.482(3)Å, b=12.543(3)Å, c=17.582(3)Å, α = 87.52(2)°, β= 72.70(2)° γ = 74.35(2)° and V= 2529(1)ų. Values of R = 0.072 and R_w = 0.097 were obtained for 487 variable parameters and 3242 reflections with I>3σ(I)

Key Words:

• Ruthenium
• phosphines
• X-ray structure
• NMR