Pi-electron conjugation effects in antiaromatic dehydro[12]- and aromatic dehydro[18]-annulenes.
N,N-Dimethylanilino-substituted perethynylated dehydro[12]- and dehydro[18]-annulenes were prepared by oxidative acetylenic coupling of cis-bisdeprotected tetraethynylethene derivatives obtained by a new photochemical route; they display strongly bathochromically shifted longest-wavelength absorption bands compared to their silyl-substituted counterparts resulting from efficient intramolecular charge-transfer between the peripheral pi-electron donors and the electron-accepting central acetylenic core.
Mitzel
Frieder
F
Laboratorium für Organische Chemie, ETH-Hönggerberg, CH-8093, Zürich, Switzerland.
Boudon
Corinne
C
Gisselbrecht
Jean-Paul
JP
Gross
Maurice
M
Diederich
François
F