Nonlinear optical properties of retinal derivatives was written by Ikeda, Hidetsugu;Kawabe, Yutaka;Sakai, Toshio;Kawasaki, Kenji. And the article was included in Chemistry Letters in 1989.Synthetic Route of C18H10N2 This article mentions the following:
Retinal derivatives I [Z = C(CN)C6H4NO2–p, C(CN)2, NC6H4NMe2–p] with electron donors or acceptors were synthesized and their 2nd order nonlinear optical properties were investigated by elec. field induced 2nd harmonic generation (EFISH) method. Retinal derivatives were found to have large 2nd order optical nonlinearities. In the experiment, the researchers used many compounds, for example, 2-(Anthracen-9-ylmethylene)malononitrile (cas: 55490-87-4Synthetic Route of C18H10N2).
2-(Anthracen-9-ylmethylene)malononitrile (cas: 55490-87-4) belongs to nitriles. Nitrile carbon shifts are in the range of 115–125 ppm whereas in isonitriles the shifts are around 155–165 ppm. In addition, Nitriles can react with alkynes, which leads to an increase in carbon chain length (carbocyanation).Synthetic Route of C18H10N2
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts