US Patent 7491544 Chiral piperidine and quinucledine ligands

Zn(II) is selectively detected in a sample by contacting the sample with a tripodal ligand with a piperidine or quinuclidine scaffold, one of which acts as a zinc sensor, in which the rigidity of the ligand scaffold is increased. The rigidity of the ligand scaffold can be increased by adding aromatic groups or cyclic hydrocarbon groups. Examples of aromatic groups include naphthalene and the like. Examples of cyclic groups include nitrogen-substituted cyclohexane and cyclohexene such as piperidine.