TERRYLENIMIDES - NEW NIR FLUORESCENT DYES

Terrylenimides 3 and 4 represent a new class of blue colorants, exhibi ting absorption maxima at 650 to 700 nm and fluorescence emissions in the NIR region (673 to 750 nm). The terrylenimides were synthesized by means of various organometallic coupling reactions, catalyzed by tran sition metal complexes (Ni-0, Pd-0) and starting from the aromatic bro mides, boronic acids, or organotin compounds. The terrylenimides have all the properties expected of excellent fluorescent dyes: high extinc tion coefficients, high fluorescence quantum yields, and very good the rmal, chemical, and photochemical stabilities. Owing to its extended p i system, 3 can reversibly accept four negative charges. By varying th e substituents, 3 and 4 can be modified to serve either as soluble dye s or as insoluble pigments.