Substituted cyclopentadienyl complexes. Part 4. The catalysed synthesis and proton nuclear magnetic resonance spectra of [Ru(η5-C5H4Me)(CO)(L)I] and [Ru(η5-C9H7)(CO)(L)I](L = phosphine or isocyanide) and the crystal structure determination of [Ru(η5-C9H7)(CO){P(CH2Ph)3}I]

Abstract

The reaction between [Ru(η⁵-C₅H₄Me)(CO)₂I] and L [L = P(OMe)₃, P(OEt)₃, P(OPrⁱ)₃, PPh₃, PMe₂Ph, Bu^tNC, or 2,6-Me₂C₆H₃NC] or [Ru(η⁵-C₉H₇)(CO)₂I] and L [L = P(OMe)₃, P(OEt)₃, P(OPrⁱ)₃, P(OC₆H₄Me-o)₃, PPh₃, or P(CH₂Ph)₃] in the presence of [{Fe(η⁵-C₅H₅)(CO)₂}₂] as catalyst yields the new substituted products [Ru(η⁵C₅H₄Me)(CO)(L)I], (1) and [Ru(η⁵-C₉H₇)(CO)(L)I], (2). The new products have been characterized by a combination of i.r. and n.m.r. spectroscopy and mass spectrometry. Ring proton resonances of complexes (1) have been assigned by nuclear Overhauser enhancement (n.O.e.) spectra [L = P(OMe)₃, PMe₂Ph, PMePh₂, or 2,6-Me₂C₆H₃NC]. The n.O.e. spectra also reveal preferential conformations of the cyclopentadienyl ring when L is large. Such spectra were also recorded for complexes (2)[L = P(OC₆H₄Me-o)₃ or P(CH₂Ph)₃] and together with coupling constant data are consistent with a ligand orientation in which L = P(CH₂Ph)₃ is found preferentially under the central carbon atom of the cyclopentadienyl indenyl ring. This was further confirmed by a crystal structure determination of [Ru(η⁵-C₉H₇)(CO){P(CH₂Ph)₃}I]·0.5C₆H₆: space group P, Z= 2, a= 9.923(2), b= 11.055(4), c= 14.543(3)Å, α= 84,52(2), β= 77.72(2), γ= 82.74(2)°, and R= 0.0560.