A novel series colorimetric and off-on fluorescent chemosensors for Fe3+ based on rhodamine B derivative.

A novel series colorimetric and off-on fluorescent chemosensors (2a, 2b, 2c) were designed and synthesized, which showed reversible and highly selective and sensitive recognition toward Fe(3+) over other examined metal ions. Upon addition of Fe(3+), sensors (2a, 2b) exhibit remarkably and 2c exhibits moderate enhanced absorbance intensity and color change from colorless to pink in CH(3)OH-H(2)O(1:1, v/v). The three compounds (2a, 2b, 2c) may therefore be applicable as rhodamine-based turn-on type fluorescent chemosensors.