Phenylacetylene transformations in clusters with Re2Fe and Re2Ni2 core. Synthesis and molecular structure of Re2Fe(CO)9(μ3,η4-CH=CHC6H4) and Cp2Ni2Re2(CO)6(μ4-PhCCCH=CHPh)

Article abstract of DOI:10.1016/0022-328X(91)83161-V

Interaction of the binuclear complex Re2(CO)8(μ-H)(μ-C<*>CPh) (I) with Fe3(CO)12 and Cp2Ni has been studied.Reaction of I with Fe3(CO)12 in refluxing toluene results in formation of a heterometallic cluster Re2Fe(CO)9 (μ₃,η⁴-CH=CH-C6H4) (II).According to the X-ray structural data, in this cluster ortho-metallation of the phenyl ring occurs and results in the appearance of the metalcyclopentadiene fragment.The core of the cluster II is an angular metal chain Re2Fe with equal Re-Fe bond lengths of 2.671(2) Angstroem and nonbonding Re(1)<*>Re(2) distances of 3.893(7) Angstroem.Reaction of I with Cp2Ni in refluxing o-xylene results in formation of the heterometallic cluster Cp2Ni2Re2(CO)6(μ₄-PhC<*>CCH=CHPh) (III) (70percent) along with the trinuclear cluster Cp3Ni3(μ-CO)2 and Re2(CO)10.According to the X-ray structural data cluster III contains a heterometallic Re2Ni2 butterfly core with a dihedral angle of 122 deg between the Re2Ni planes.Dimerisation of the two acetylene fragments gives a ligand which is coordinated between the ReNi2 wings only by a C<*>C triple bond (with the length of 1.48(2) Angstroem), the second hydrocarbon fragment CH=CHPh is non-coordinated.