Dimers of Nineteen‐Electron Sandwich Compounds: Crystal and Electronic Structures,and Comparison of Reducing Strengths |
| |
| Authors: | Dr Swagat K Mohapatra Alexandr Fonari Dr Chad Risko Dr Kada Yesudas Karttikay Moudgil Dr Jared H Delcamp Prof Tatiana V Timofeeva Prof Jean‐Luc Brédas Prof Seth R Marder Dr Stephen Barlow |
| |
| Institution: | 1. School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, GA 30332‐0400 (USA);2. Present address: KIIT University, Bhubaneswar, Orissa 751024 (India);3. Department of Chemistry, New Mexico Highlands University, Las Vegas, NM 87701 (USA);4. Present address: Department of Chemistry and Center for Applied Energy Research (CAER), University of Kentucky, Lexington, KY 40506‐0055 (USA);5. Present address: Department of Chemistry, University of Mississippi, University, MS 38677 (USA);6. Present address: Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology – KAUST, Thuwal 23955‐6900 (Kingdom of Saudi Arabia) |
| |
| 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 X‐ray 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. |
| |
| Keywords: | density functional calculations doping redox chemistry sandwich complexes structure elucidation |
|
|
