897963-70-1Relevant academic research and scientific papers
New stable, isolable triarylmethyl based dyes absorbing in the near infrared
Villalonga-Barber, Carolina,Steele, Barry R.,Kova?, Veronika,Micha-Screttas, Maria,Screttas, Constantinos G.
, p. 2785 - 2792 (2006)
A series of new intensely coloured multicharged methylium compounds containing the 4-[2-ferrocenylethenyl]phenyl group and with significant electronic absorption in the near infrared have been prepared via acidification of the tertiary carbinols obtained by reaction of 4-[FcCH{double bond, long}CH]C6H4Li with diethyl isophthalate, diethyl terephthalate, diethyl phthalate or the triethyl ester of 1,3,5-benzene carboxylic acid. Even more stable dyes were prepared from two new triarylmethanol derivatives containing 2,6-dimethoxy-4-[2-(ferrocenyl)ethenyl]phenyl or 2,6-dimethoxy-4-[2-[4-(dimethylamino)phenyl]ethenyl]phenyl groups which were prepared by reaction of 4-[FcCH{double bond, long}CH]-2,6-MeO2C6H2Li or 4-[4-Me2NC6H4CH{double bond, long}CH]-2,6-MeO2C6H2Li (Fc = ferrocenyl) with diethyl carbonate. These carbinols on treatment with acid deposit dark-purple crystals which have been isolated and characterised spectroscopically. They absorb in the near infrared and, whereas their solutions begin to decolourise only after several days, they display long-term stability to air and moisture in the solid state.
