Probing CH/pi interactions between [60]fullerene and phenyl substituted acenes

ORGN 775

James E. Rainbolt, rainbolt@unh.edu and Glen P. Miller, gpm@unh.edu. Department of Chemistry, University of New Hampshire, 23 College Road, Parsons Hall, Durham, NH 03824
To explore the potential role of CH/pi interactions in the cycloaddition of [60]fullerene across phenyl substituted acenes, we synthesized 1,4-diphenyltetracene and 1,4,8,11-tetraphenylpentacene and studied their reactivities with [60]fullerene. [60]Fullerene shows an unusual propensity for cycloaddition across the 5,12 position of 1,4-diphenyltetracene and the 5,14 and 7,12 positions of 1,4,8,11-tetraphenylpentacene compared to other dienophiles. This reactivity is compared and contrasted to the reactivity of other dienophiles including dimethyl acetylenedicarboxylate (DMAD), ethylene, singlet oxygen, and maleic anhydride. NOESY (nuclear Overhauser effect spectroscopy) methods are especially useful for the discrimination of 5,12 and 6,11 cycloaddition regioisomers of 1,4-diphenyltetracene and will be discussed. The role of CH/pi interactions will be discussed.