2b, 2c, 2d, 2e, and 2f, respectively. All of the 12~, 12d, 12e, l2f-benzo [g, h, i] perylene derivatives show the NMR spectral characteristics to be expected for bridged [18lannulenes having a strong diamagnetic ring current. The effect of different bridging groups upon the magnitude of the ring current is discussed. For those bridged [18lannulene derivatives (2d and 2f) having internal methyl groups, dehydrogenation or oxidation leads to the ...
