CHED 1218 |
| Phosphine pincer-ligated iridium complexes, such as [p-X-C6H3-2,6-(Y-PR2)2]IrH2; X = MeO, Me, H, F, C6F5, Y = CH2, O, R = iso-propyl, tert-butyl, have been reported as effective dehydrogenation catalysts of alkanes. This process can occur both with and without a hydrogen acceptor, but traditionally an acceptor such as tert-butylethylene or norbornene is used. Both experimental and computational reports on this chemistry have been published by others. Following implied mechanisms our efforts have focused on frontier orbital analysis of several intermediates in the dehydrogenation process of (PCP)Ir species. Specifically, orbital interactions throughout the C-H bond activiation were studied. Comparing calculated orbital energies with experimental TON's provided a linear relationship for the phosphinite (Y= O) PCP complexes. For the p-X derivatives above, a poor fit (R2 = 0.80) was observed; however, removing the anomalous p-F data the correlation improved dramatically (R2 = 0.98). The presented work will include orbital energies for complexes along the dehydrogenation mechanism and observed trends. |
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Undergraduate Research Poster Session: Inorganic Chemistry
2:00 PM-4:00 PM, Monday, March 26, 2007 Hyatt Regency Chicago -- Riverside Center, Poster
Division of Chemical Education |