Site-selective PMe3 addition to the donor-acceptor complex Ru2(CO)6[(Z)-Ph2PCH=CHPPh2]. X-ray diffraction structure of Ru2(CO)5(PMe3) [(Z)-Ph2PCH=CHPPh2]

Article abstract of DOI:10.1016/S0020-1693(97)05616-8

The diphosphine-bridged ruthenium dimer Ru₂(CO)₆[CZ)-Ph₂PCH=CHPPh₂] (1) reacts with added PMe₃ under photochemical and thermal conditions and by Me₃NO-induced activation at the phosphine-substituted ruthenium center to give Ru₂(CO)₅(PMe₃)[(Z)-Ph₂PCH=CHPPh ₂] (2). The entering PMe₃ is found to adopt axial and equatorial sites in 2, as confirmed by solution ¹H and ³¹P NMR spectroscopy measurements. The solid-state structure of the equatorially substituted isomer 2e has been established by X-ray diffraction analysis. 2e crystallizes in the triclinic space group P1: a=10.8602(7), b=11.1801(9), c=15.680(1) A, α=79.788(6), β=82.838(6), γ=66.450(5)°, V=1714.6(2) A³, Z=2, D_calc=1.578 g cm^-3; R=0.0574, R_w=0.0627 for 3695 observed reflections with I > 3σ(I).