The reactions of phenylacetylene with naphthalene complexes of europium and ytterbium. Molecular structure of [IYbC CPh(DME)(2)](2)

Reactions of naphthaleneeuropium and naphthaleneytterbium, C(10)H(8)Ln(DME) (Ln = Eu or Yb), with phenylacetylene are accompanied by the formation of the C-C bond and yield the complexes of composition Ph(2)C(4)H(2)Ln(DME)(2). Hydrolysis of the Ph(2)C(4)H(2)Ln(DME)(2) complexes affords a mixture of isomers of 1,4-diphenyl-1,3-butadiene. Reactions of C10H8[LnI(DME)(2)](2) with PhC=CH yield mixed iodine-ethynyl complexes [ILn(mu-C=CPh)(DME)(2)](2). According to the data of X-ray diffraction analysis, the ytterbium complex consists of two YbI(DME)(2) units bonded through two bridging C=CPh groups. The crystals of this complex belong to the space group P2(l)/c. The central cyclic Yb-C-Yb-C fragment is planar; the C(1)-Yb(1)-C(1') angle is 86.4(3)degrees. The Yb-C bond lengths are 2.584(8) and 2.603(9) Angstrom.