CHED 268 |
| The [Fe(CN)x(CO)y]2- species has been the subject of numerous experimental investigations in recent years, as the Fe(CO)(CN) moieties were found to be the catalytic centers of hydrogenase enzymes. We report the IR spectrum of the [Fe(CN)4(CO)2]2- complex in different solvents, ranging from non-polar to highly polar. The carbonyl stretching frequency showed a strong dependence on the nature of the solvent, while the cyano stretching frequency varied only slightly. To test the hypothesis that the solvent effect is due to hydrogen bonding between the complex and the solvent molecules, we calculated the IR spectra of the complex, by ab initio methods, in the gas phase and in the presence of explicit solvent (H2O) molecules. The blue shift correlates well with the occupancy of the π* orbitals of the carbonyl bond, suggesting that the extent of π back bonding decreases due to hydrogen bonding between the H2O and the cyano ligand. |
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Undergraduate Research Poster Session: Inorganic Chemistry
2:30 PM-4:30 PM, Monday, 11 September 2006 Moscone Center -- Hall D, Poster
Division of Chemical Education |