Koenigstein, Christian published the artcileOrigin of the high-energy emission of 1,1′-diethyl-2,2′-cyanine dye, Recommanded Product: 1-Ethyl-2-methylquinolin-1-ium iodide, the publication is Journal of Photochemistry and Photobiology, A: Chemistry (1994), 84(3), 245-8, database is CAplus.
In addition to the yellow emission ascribed to the J aggregates of 1,1′-diethyl-2,2′-cyanine, this compound also exhibits a high-energy emission around 400 nm in dilute aqueous solutions (c<10-3 mol l-1). It was found using time-resolved emission measurements that protonation of 1,1′-diethyl-2,2′-cyanine is responsible for this emission. At pH<4, the excited state protolytic reaction competes with ground state protonation. Both pathways give the same excited species, luminescing at 400 nm. The non-protonated form shows only weak fluorescence. The excited state lifetime of the protonated form is 4.5 ns.
Journal of Photochemistry and Photobiology, A: Chemistry published new progress about 606-55-3. 606-55-3 belongs to iodides-buliding-blocks, auxiliary class Quinoline,Salt, name is 1-Ethyl-2-methylquinolin-1-ium iodide, and the molecular formula is C12H14IN, Recommanded Product: 1-Ethyl-2-methylquinolin-1-ium iodide.
Referemce:
https://en.wikipedia.org/wiki/Iodide,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com