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7649probably one of the alkene-chromium species described above. This argument suggests an intermediate chromium-hydrogen system possibly containing a a-allyl moiety. The activation of the C-H bond is apparently related to the resonance stabilization gained upon formation of the arene and the further stabilization from the tendency of chromium to form strong a bonds with arene ligands. This unusual nature of our chromium-cyclohexene reaction system is further demonstrated by the absence of the 01-igomerization products observed when 1-butene is cocondensed with chromium atoms as reported by Skell;s the addition of D 2 0 is necessary to generate oligomeric products in the case of 1-propene, but we observed oligomerization in the absence of a proton source.We are currently attempting to further elucidate the mechanistic details of the process involved in this reaction, as well as optimizing the process as a synthetic method for the convenient preparation of mixed, a-complexed arene chromium compounds. Acknowledgment. We acknowledge our debt to the Robert A. Welch Foundation for its support of this work.

= 1.39 g cm-'. Nicolet R3m diffractometer, w-scan, graphite-monochromated CuKe radiation. Both structures were solved by direct methods and refined anisotropically to give R =0.166 (R,=0.166) and R=0.082 (R,=0.083), respectively, for 2693 and 4225 independent observed reflections [8550", lFol > 3u(lF01)]. The high R value for 7 is a consequence of disorder in the polyether chains and also reflects the presence of disordered solvent fragments in the lattice. Further details of the crystal structure investigations can be obtained from the Director of Cambridge CryStallOgrdphic Data Centre, Lensfield Road, Cambridge CB2 IEW (England), by quoting the full literature citation.