阴离子生色传感器基于质子转移机理

带有酚羟基的化合物1,2和3能够用作阴离子选择性生色传感器.它们对氟离子和醋酸根离子表现出明显的颜色变化,而对其它卤素离子没有响应.这种选择性可以用质子转移机理来解释.化合物1 含有两个酚羟基,在和过量的氟离子作用时,两个酚羟基表现为逐步去质子化.紫外光谱,核磁氢谱,核磁氟谱证明了这一点.

Colorimetric Sensors for Anion Recognition Based on the Proton Transfer Signaling Mechanism

Phenolic hydroxyl based sensors N,N‐bi(salicylidene)‐1,2‐phenylenediamine ( 1 ), 2‐(4‐nitrophenylimino)‐ methyl] phenol ( 2 ) and 2‐p‐tdylimino methyl] phenol ( 3 ) bearing Schiff‐base groups can act as selective colorimetric sensors for anions, which exhibit distinct color changes in the presence of fluoride, but show no response to other halogen anions. They also give response to acetate, which is clearly visible to the naked eyes. The selectivity can be rationalized on the proton transfer signaling mechanism. The sensor 1 containing plural phenolic groups undergoes stepwise deprotonation of the two O–H fragments when it interacts with excess fluoride, which is confirmed by UV‐Vis, ¹H NMR and ¹⁹F NMR spectroscopic methods.