Ion-sensing properties of thiophene-based oxazol-5-ones

Abstract

Seven fluorescent thiophene-based oxazol-5-one derivatives were prepared via Erlenmeyer reaction of 2-thiophenecarboxaldehyde and 3-thiophenecarboxaldehyde with different aryl glycine intermediates. Their absorption and emission properties were investigated in solution environment and in the solid film matrix of polyvinylchloride. Moreover, the fluorescence sensing abilities to iron (III), cobalt (II), nickel (II), zinc (II) and copper (II) ions were examined in polyvinylchloride matrix. Thiophene-based oxazol-5-one derivatives revealed high sensitivity and selectivity toward iron (III). A good linearity with a correlation coefficient of 0.99 was observed in the concentration range of 1.0 × 10−7 to 1.0 × 10−3 M iron (III) for 2-phenyl-4-(2-thienylmethylene)oxazol-5-one, 2-(3-thienyl)-4-(2-thienylmethylene)oxazol-5-one and 2-(3-thienyl)-4-(3-thienylmethylene)oxazol-5-one.