(1)H NMR PATTERNS OF ANTIAROMATIC SYSTEMS: PARATROPIC DISPLACEMENT DEPENDENCE UPON LUMO-HOMO ENERGY GAP

Article abstract of DOI:10.1016/S0040-4039(00)85836-0

(1)H NMR chemical shifts of antiaromatic species reveal an enhanced paratropic displacement.The high-field shifts exhibited by doubly charged benzenoid polycycles were shown to be strongly related to the LUMO-HOMO energy gap in these antiaromatic systems.As the gap decreases, a larger paratropic shift was observed.