Just a couple of transition metal complexes of the familiar triiodide anion are known. To investigate the bonding in these, as well as isomeric possibilities, we examined theoretically adducts of I3 - with model organometallic fragments, [Cr(CO)5] and [Mn(CO) 5]+. Bonding energy computations were augmented by a Natural Bond Orbital (NBO) perturbation theory analysis and Energy Decomposition Analysis (EDA). The bonding between I3 - and the organometallic fragment is substantial, especially for the electrostatically driven anion-cation case. "End-on" coordination is favored by 5-13 kcal/mol over "side-on" (to the central I of I3 -), with a ∼10 kcal/mol barrier for isomerization. A developing asymmetry in the I-I bonding of "end-on" coordinated I 3 - led us to consider in some detail the obvious fragmentation to a coordinated I- and free I2. While the signs of incipient fragmentation in that direction are there, these is a definite advantage to maintaining some I- to I2 bonding in triiodide complexes. © 2013 American Chemical Society.
|Original language||English (US)|
|Number of pages||11|
|State||Published - May 31 2013|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): CHE-0910623
Acknowledgements: Our work was supported by the National Science Foundation, Research Grant CHE-0910623. Computational facilities provided by KAUST (King Abdullah University of Science and Technology) Supercomputing Laboratory are gratefully acknowledged.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.