Dimers of nineteen-electron sandwich compounds: Crystal and electronic structures, and comparison of reducing strengths

Abstract
The dimers of some Group 8 metal cyclopentadienyl/ arene complexes and Group 9 metallocenes can be handled in air, yet are strongly reducing, making them useful n-dopants in organic electronics. In this work, the Xray molecular structures are shown to resemble those of Group 8 metal cyclopentadienyl/pentadienyl or Group 9 metal cyclopentadienyl/diene model compounds. Compared to those of the model compounds, the DFT HOMOs of the dimers are significantly destabilized by interactions between the metal and the central C-C σ-bonding orbital, accounting for the facile oxidation of the dimers. The lengths of these C-C bonds (X-ray or DFT) do not correlate with DFT dissociation energies, the latter depending strongly on the monomer stabilities. Ru and Ir monomers are more reducing than their Fe and Rh analogues, but the corresponding dimers also exhibit much higher dissociation energies, so the estimated monomer cation/neutral dimer potentials are, with the exception of that of [RhCp2]2, rather similar (-1.97 to-2.15 V vs. FeCp2 +/0 in THF). The consequences of the variations in bond strength and redox potentials for the reactivity of the dimers are discussed.

Citation
Mohapatra, S. K., Fonari, A., Risko, C., Yesudas, K., Moudgil, K., Delcamp, J. H., … Barlow, S. (2014). Dimers of Nineteen-Electron Sandwich Compounds: Crystal and Electronic Structures, and Comparison of Reducing Strengths. Chemistry - A European Journal, 20(47), 15385–15394. doi:10.1002/chem.201404007

Publisher
Wiley

Journal
Chemistry - A European Journal

DOI
10.1002/chem.201404007

Relations
Is Supplemented By:
  • [Dataset]
    Mohapatra, S. K., Fonari, A., Risko, C., Yesudas, K., Moudgil, K., Delcamp, J. H., … Barlow, S. (2014). CCDC 1005757: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc12rks5. DOI: 10.5517/cc12rks5 HANDLE: 10754/624330
  • [Dataset]
    Mohapatra, S. K., Fonari, A., Risko, C., Yesudas, K., Moudgil, K., Delcamp, J. H., … Barlow, S. (2014). CCDC 1005758: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc12rkt6. DOI: 10.5517/cc12rkt6 HANDLE: 10754/624331
  • [Dataset]
    Mohapatra, S. K., Fonari, A., Risko, C., Yesudas, K., Moudgil, K., Delcamp, J. H., … Barlow, S. (2014). CCDC 1005759: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc12rkv7. DOI: 10.5517/cc12rkv7 HANDLE: 10754/624332
  • [Dataset]
    Mohapatra, S. K., Fonari, A., Risko, C., Yesudas, K., Moudgil, K., Delcamp, J. H., … Barlow, S. (2014). CCDC 1005760: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc12rkw8. DOI: 10.5517/cc12rkw8 HANDLE: 10754/624333
  • [Dataset]
    Mohapatra, S. K., Fonari, A., Risko, C., Yesudas, K., Moudgil, K., Delcamp, J. H., … Barlow, S. (2014). CCDC 1005761: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc12rkx9. DOI: 10.5517/cc12rkx9 HANDLE: 10754/624334
  • [Dataset]
    Mohapatra, S. K., Fonari, A., Risko, C., Yesudas, K., Moudgil, K., Delcamp, J. H., … Barlow, S. (2014). CCDC 1005762: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc12rkyb. DOI: 10.5517/cc12rkyb HANDLE: 10754/624335

Permanent link to this record