PERSISTENT OXIDATION DICATIONS OF DIALKYL-PERYLENE AND TETRAALKYL-PERYLENE AND DIBENZO[CD,LM]PERYLENE - CHARGE-DISTRIBUTION MODE, SUBSTITUENT EFFECTS AND CONFORMATIONAL ASPECTS

Starting with appropriate alkylnaphthalenes, 3,10-dimethyl- 2, 3,10-di ethyl- 3, 2,3,10,11-tetramethyl- 4 and 3,4,9,10-tetramethyl-perylene 5 were synthesized by a sequence of radical cation and radical anion co upling steps, Persistent oxidation dictations of parent perylene 1, al kylperylenes 2-5 and dibenzo[cd,lm]perylene 6 were generated in SbF5-S O2ClF. Based on 1D- and 2D-NMR experiments combined with AMI calculati ons the charge delocalization mode in the dications was deduced, The t otal deshielding (Sigma Delta delta(13)C), substituent effects, confor mational/ geometrical changes and tropicity in the dications are exami ned, Whereas alkylperylene dications represent 18 pi electron Huckel d ictations with a diamagnetic ring current (more diatropic than their n eutral precursors), the 24 pi (20 pi periphery) dication of dibenzoper ylene exhibits a paramagnetic ring current which greatly shields its p rotons (more paratropic than neutral hydrocarbon).