Lanthanoid-olefin complex formation: A matrix isolation ultraviolet- visible and infrared study of the direct synthesis of (C(2)H (4))(n)Eu using europium atoms.

Eu(C(2)H(4)) complexes have been synthesized at 12K by codepositing Eu atoms with ethylene, neat or doped in Ar or Xe. Uv-visible absorption spectroscopy of the highest stoichiometry product revealed a broad, intense visible transition centered at 537 nm. The complex is unstable above 50K, consistent with the absence of any evidence for reaction in 77K metal vapor reactions. Optical spectroscopy of the products formed in dilute matrices indicated the formation of a lower stoichiometry Eu-C(2)H(4) complex.