A new class of rhodamine luminophores: Design, syntheses and aggregation-induced emission enhancement
A new class of rhodamine luminophores, 3′,3″- bis(oxospiroisobenzofuran)-3,7-bis(dialkylamino)benzopyrano-xanthene derivatives (ABPX), have been successfully developed. The emission behavior of ABPX series is directly opposite to the concentration quenching of conventional rhodamine dyes. ABPX series exhibit aggregation-induced emission enhancement (AIEE).
Syntheses and photophysical properties of aminobenzopyranoxanthene dyes containing various alkyl chains at amine moieties
Aminobenzopyranoxanthene (ABPX) dyes containing linear n-alkyl chains at amino groups were synthesized, and their cis and trans stereoisomers were isolated. Detailed spectrophotometric studies revealed that all the ABPX derivatives exhibited fluorescence emission in the far-red and near-infrared wavelength regions, and their fluorescence quantum efficiency increased with increasing n-alkyl chain length. Almost no differences in photophysical properties were observed between the cis and trans stereoisomers.