| Popis: |
Short syntheses and X-ray crystal structures are reported for two new geodesic polyarenes, pentaindenocorannulene (1, C50H20) and tetraindenocorannulene (2, C44H18). These extended aromatic π systems constitute the largest curved subunits of C60 ever prepared. In agreement with theoretical predictions, the trigonal carbon atoms at the cores of these new hydrocarbons suffer even greater pyramidalization than that exhibited by the carbon atoms of C60 (average POAV angles = 12.6, 12.1, and 11.6° for 1, 2, and C60, respectively). These syntheses of such highly curved π systems by solution phase methods, starting from compounds that were derived from planar starting materials also by solution phase methods, demonstrate unequivocally that rational chemical syntheses of fullerenes, carbon nanotubes, and related carbon-rich molecules should all be possible using exclusively solution chemical methods! Recourse to high-temperature gas-phase pyrolysis should not be necessary. The synthesis of 1 begins with a 5-fold ... |
