ORGN 681 |
| Diaryl acetylenes, bearing at least one nitrogen in the aryl substituent, undergo efficient photocycloaddition to 1,4-cyclohexadiene with formation of 1,5-diaryl substituted homoquadricyclanes. Pyrazyl aryl acetylenes behave similaly under identical conditions, however, the primary homoquadricyclane products undergo a secondary photochemical rearangement leading to diaryl substituted tricyclo[3.2.1.04,6]oct-2-enes. We will report mechanistic and photophysical studies aimed at determinining spin multiplicity of excited states involved into these photocycloadditions as well as structural and electronic factors controlling rate and efficiency of these processes. Selected 1,5-diaryl substituted homoquadricyclanes display interesting behavior in forming complexes with metal salts. For example, in the case of silver nitrate, depending on the ratio of ligand:metal, silver coordination sphere can be altered. Interestingly, the homoquadricyclane polycyclic framework orients the terminal aryl (4-pyridyl, 4-tetrafluoropyridyl, phenyl etc.) groups in an almost perfect 60o angle renders such molecules promising building blocks in the design and synthesis of supramolecular complexes.
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Physical Organic Chemistry: Calculations, Mechanisms, Photochemistry, and High-Energy Species
1:00 PM-5:00 PM, Wednesday, 16 March 2005 Convention Center -- Room 11A, Oral
Division of Organic Chemistry |
