An infrared study of the structures of cyclopentadienyl compounds of copper(I) and mercury(II)

F. A. Cotton, Tobin J Marks

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The infrared spectra of the copper(I) compounds (C5H5)CuPR3, R = C2H5, C4H9, and the mercury compounds (C5H5)2Hg and C5H5HgCl have been reinvestigated. Comparisons are made with the spectra of compounds which serve as models for pentahapto- and monohaptocyclopentadienylmetal systems. The following conclusions emerge unequivocally: (1) contrary to the belief which has prevailed since 1956, the copper compounds contain pentahapto (i.e., "sandwich-bonded" rings, and (2) the mercury compounds contain monohapto (i.e., σ-bonded) rings. The significance of these results is discussed in relation to the physical, chemical, and dynamical properties of the molecules.

Original languageEnglish
Pages (from-to)7281-7285
Number of pages5
JournalJournal of the American Chemical Society
Issue number26
Publication statusPublished - 1969


ASJC Scopus subject areas

  • Chemistry(all)

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