| 摘要 |
2-Methyl-4,4a-dihydro-3H-carbazolium salts that are useful as dye precursors and dyes derived from those precursors are disclosed. The salts are described by the formula <CHEM> wherein R<1> represents an alkyl, aryl, sulfoalkyl, carboxyalkyl, sulfatoalkyl, alkoxyalkyl, acyloxyalkyl, dialkylaminoalkylene, cycloaminoalkylene, acyl, or alkenyl group having from 1 to 18 carbon atoms; R<2> represents an alkyl group having up to 18 carbon atoms; R<3>represents hydrogen or an alkyl group having from 1 to 18 carbon atoms; R<4> represents hydrogen or an alkyl group having from 1 to 18 carbon atoms; R<5> represents hydrogen, nitro, carboxyl, sulfo, hydroxy, halogen, phospho, or an alkoxy, thioalkoxy, oxyalkyl, acyl, alkyl, aryl, or amino group having up to 18 carbon atoms; wherein any two groups R<5>, or R<4> and a group R<5>, or R<1> and R<4> may together form a substituted or unsubstituted aryl, heteroaryl, aliphatic, or heteroaliphatic ring; X represents an anion; and a and b represent positive integers such that a equals b. The salts have a partially saturated ring system that rigidifies the chromophore in the precursor and in dyes derived from it. The rigidified chromophores have narrowed absorption bands relative to corresponding non-rigid chromophores. Dyes prepared from the dye precursors of the invention typically have good solubility in non-polar solvents. |
