Poly(1,4-diethynylphenylene-4,6-pyrimidine)s for fluorescence detection of mercury(II) ion

Abstract

A series of alternating conjugated polymers (poly (1,4-diethynylphenylene-4,6-pyrimidine) (PI) and poly (2,5-diheptyloxy- 1,4-diethynyl-phenylene-4,6-pyrimidine) (PII) were synthesized via Sonogashira coupled reaction. Chemical structure of conjugated polymers were certified by NMR and FT-IR. The PIII(poly (2,5-bis(dodecoxy)-1,4-diethynyl- phenylene-4,6-pyrimidine) previously reported by our group to illustrate the application of such polymer. The fluorescence of PIII were efficiently quenched when introduced I-, the specificity of the polymer for I- was verified by experiments and detection limit reaches 5.19 × 10-7 mol/L. Thanks to the high association constant between Hg2+ and I-, the fluorescence of PIII/I- system recovered with the addition of Hg2+. The detection limit of Hg2+ reaches ~4.92 × 10-6 mol/L for PIII/I- complex system. PIII/I- could act as high selective, sensitive and anti-interference optical probe for Hg2+.