Novel Hydrazone-Based Tripodal Sensors： Single Selective Colorimetric Chemosensor for Acetate in Aqueous Solution

A series of novel tripodal colorimetric anion sensors based on hydrazone CH=N--NH groups have been synthesized and their recognition behavior with anionic guests has been studied. In DMSO solutions, sensors 1 and 2 show colorimetric responses for F^-, H2PO4 and AcO^-, while in DMSO/H20 （9 ： 1, V/V） solutions, sensor 1 shows single selectivity for AcO^-. ^1H NMR titration confirms that the tripodal sensors could bind anions through the collaboration of three hydrazone groups and anions residing in the central cavity of the sensors.