E Hückel 1931 4n+2 aromaticity; modern modern foundational text + Möbius-Hückel anti-aromaticity + π-electron-delocalization + NICS.
E Hückel 1931 4n+2 aromaticity; modern modern foundational text + Möbius-Hückel anti-aromaticity + π-electron-delocalization + NICS.