CHED 1227 |
| The hypervalency of tetrasubstituted germanes was explored using germanium-73 NMR spectroscopy. Potentially coordinating symmetrical compounds of the form Ge[O(CH2)nN(CH3)2]4, Ge[O(CH2)nOCH3]4, and Ge[O(CH2)2SCH3]4 (where n = 2, 3, 4) were synthesized and analyzed using germanium-73 NMR. Although these compounds should have long relaxation rates and sharp resonances as a result of tetrahedral symmetry, these compounds have relatively broad or no observable resonances. We hypothesize that this is a result of intramolecular coordination which distorts the symmetry around the germanium nucleus. However, this small amount of coordination is not sufficient to change the electron density at the germanium nucleus enough to cause a low frequency shift. Intermolecular coordination of germanium tetrahalides with bases such as tributylphosphine oxide (TBPO), tributylphosphine (TBP), and triethylphosphine oxide (TEPO) result in both a low frequency shift and an increase in line widths in germanium resonance. |
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Undergraduate Research Poster Session: Inorganic Chemistry
2:00 PM-4:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster
Division of Chemical Education |