Two silver(I) complexes: Synthesis, structures, and electrochemicalH2O2sensing

Abstract Two new silver(I) complexes, formulated as [Ag 2 (L 1 ) 2 ](picrate) 2 ( 1 ), {[Ag 2 (L 2 ) 2 (terephthalate)](C 2 H 5 OH) 3 (H 2 O)} n ( 2 ) (L 1 = 1,3‐bis(2‐benzimidazyl)benzene, L 2 = 1,3‐bis(1‐methylbenzimidazol‐2‐yl)‐2‐thiapropane), were synthesized and characterized by X‐ray crystallography, elemental analysis, infrared, and UV–Vis spectroscopy. The crystal analysis results showed that the complexes exhibited different structures: binuclear for 1 and one‐dimensional polymeric for 2 . Their Ag(I) centers displayed different coordination geometric structures: two‐coordinated linear in 1 , whereas four‐coordinated distorted tetrahedron in 2 . The electrochemical sensing performance of Ag(I) complexes modified carbon paste electrode (CPE‐1 and CPE‐2) toward hydrogen peroxide (H 2 O 2 ) was evaluated by chronoamperometry in 0.2 M phosphate buffer saline (pH = 6) at −0.2 V. The CPE‐1 was found to have a wide linear response from 1.0 × 10 −5 to 4.0 × 10 −3 M, lower detection limit of 1.73 μM, excellent anti‐interference ability, and stability. The CPE‐2 does not have recognition properties for H 2 O 2 , which may be due to the large steric hindrance around Ag(I) centers that is not easy to combine with H 2 O 2 to form a catalytic transition state. The above studies proved that Ag(I) complexes can be used as effective components of electrode materials for the electrochemical recognition of H 2 O 2 .