Investigation of Chemosensing and Color Properties of Schiff Base Compounds Containing a 1,2,3-triazole Group.

A series of Schiff base compounds (ER1-ER5) containing a 1,2,3-triazole and carboxylic acid groups were synthesized and their chemosensory properties towards anions (I-, CO32-, SO42-, NO2-, NO3-, CH3COO-, ClO3-, CNO-, N3-) and cations (Al3+, Ag+, Co2+, Cr3+, Cu2+, Fe3+, Hg2+, Mn2+, Ni2+, Zn2+, Cd2+, Pb2+). The compounds were also used as fluorescence probs for the detection of nitroaromatic compounds. The structural characterization of the synthesized compounds was elucidated using methods such as FT-IR, UV, FL, LC-MS, MALDI-TOF MS, 1H(13C) NMR. The effect of substitute groups (-CH3, -OCH3, -OH, -Cl and -Br) on the synthesized Schiff bases (ER1-ER5) on the chemosensory properties were compared. As the groups changed, the sensor and quenching effects of the molecule against anions and cations changed. Compound ER3 having methoxy (OCH3) group exhibited selective sensor properties against Fe3+ ion while compound ER5 with a chloride substitute (Cl) group showed selectivity for Cr3+ ion under 254 nm UV-lamp. The substitute effect was also observed for the sensing of anions. Under 254 nm UV-lamp, ER2 having the -OH group has a selective sensing property for CNO- and ER4 with the bromide (Br) group exhibited selectivity for N3- ion. The synthesized Schiff base compounds were also tested as fluorescence probs for the sensing of some nitroaromatic explosives.