Photochemistry of host-guest complexes. VIII. The photoreaction of pyrazinedicarbonitrile derivatives having a crown ether moiety in the presence of an ω-diethylamino-1-alkanaminium salt

Irradiation of 5-(benzo-18-crown-6)-4′-yl]pyrazine-2,3-dicarbonitrile and 5-(3,4-dimethoxyphenyl)pyrazine-2,3-dicarbonitrile in the presence of ω-diethylamino-l-alkanaminium ion caused the reductive decyanation to give pyrazinemonocarbonitrile derivatives. The reaction is initiated by a single electron transfer from the tertiary amino group of the diamine. The complex formation between the crown ether moiety and the ω- diethylamino-l-alkanaminium ion enhances the photoreaction.