1-Nitronyl nitroxide pyrene as a new off-on fluorescent chemosensor for Cu2+

1-Nitronyl nitroxide pyrene (1) has been investigated as a new off-on fluorescent chemosensor for metal ions in CH3CN. Compound 1 shows high selectivity and sensitivity to Cu2+ with a detection limit as low as 3.60 x 10(-7) M. A coordination mechanism between compound 1 and Cu2+ has been well proven by UV-vis and ESR results.