Syntheses and Structural Studies of Several Group 8 Metal Complexes Derived from 1,3-Butadiyne

Abstract

As part of an extensive investigation into the chemistry of complexes containing metal-ligand centers linked by chains of C(sp) atoms, the preparation, characterization, and single-crystal X-ray diffraction molecular structure determinations of four complexes {MLn}-C≡CC≡C-{M’L’m} [MLn = Ru(dppe)Cp*, M’L’m = Fe(dppp)Cp* (1), Ru(dppe)Cp* (2), MLn = M’L’m = Os(PPh₃)₂Cp (3)], and {Cp*(dppe)Ru}C≡CC≡C{trans-RuCl(dppe) ₂} (4), in which the alternating C(sp)–C(sp) bonds have values between 1.375 and 1.40 Å (single) and between 1.20 and 1.259 Å (triple), respectively, are described. In addition, a structure determination of Ru₃(μ-H){μ3-C2C≡C[Ru(PPh₃)₂Cp]}(CO)₉ (5) shows that the C2 fragment attached to the HRu3 cluster shows the expected lengthening [to 1.311(7) Å] and bending at the two carbon atoms [to 152.6(6) and 157.6(5)°] (resulting from back-bonding from the Ru3 cluster into the C≡C π* orbitals) compared with the essentially linear Ru–CC– moiety [C≡C 1.222(6) Å, angles at C of 178.0(5), 172.3(6)°].