Charge delocalization pathways in persistent 1-pyrenyl-, 4-pyrenyl-, and 2-pyrenylmethylcarbenium ions as models of PAH-epoxide ring opening: NMR studies in superacids and Am1 calculation

摘要

The relative stability, magnitude, and mod of charge delocalization into the pyrene moiety (Py) were evaluated for a series of tertiary and secondary 1-pyrenylmethylcarbenium ions PyC+R_1R_2 and PyC+R_3H (with R_1=R_2=Me and Ph;R_3=Me, Ph, CH_2Ph, and (CH_2)_10Me), 4-pyrenylmeth- ylcarbenium ions (with R_1=R_2=Me; R_3=Me and Ph), and 2-pyrenylmethylcarbenium ions (with R_1=R_2=Me). The carbocations were generated from the corresponding carbinols by protonation With FSO_3H/SO_2CIF.