X-Ray evidence for a mononuclear s-trans-η 4 -1,3-diene complex; molecular structure of Zr(η 5 -C 5 H 5 ) 2 (s-trans-PhCHCH–CHCHPh)

Novel s-trans-η4-co-ordination of butadiene to a single metal atom was Confirmed by the X-ray crystal structure analysis of thermally stable Zr(η5-C5H5)2(PhCHCH–CHCHPh); this agrees with the solution structure determined by 1H n.m.r. spectroscopy.