Synthesis and Polymerization of Monomers possessing Chemiluminescence Properties and Their Application Areas

A novel class of chemiluminescence (KL) compounds was designed, synthesized and characterized; 2,3-dihydro-thieno[3,4-d]pyridazine-1,4-dione (T-Lum), 2,3-dihydro-furo[3,4-d]pyridazine-1,4-dione (FLum) and 2,3-dihydro-pyrrolo[3,4-d]pyridazine-1,4-dione (P-Lum). The KL reaction of the compounds in alkali medium was examined by using hydrogen peroxide and potasium permanganate oxidants and a possible KL mechanism was investigated. Synthesized compounds are especially sensitive to Fe+3 ion and this property makes them amenable to use as iron sensors. Also, the sensitivity of these materials towards iron makes them a promising candidate in forensic area to detect trace amount of blood at crime scene. Compounds are also sensitive both iron and blood samples even at lower concentration. By using the sensitivity of compounds towards hydrogen peroxide, the detection of many analytes will be possible. Beside the KL property, the electrochemiluminescence (EKL) property of the materials makes them very precious. Since the oxidation of pyridazine ring occurs before the aromatic rings, electropolymerization of the functionalized pyrrole, furan and thiophene compounds with pyridazine rings were not possible. To overcome this problem, new compounds, which have lower oxidation potential than that of pyridazine ring, were designed, synthesized and characterized; 5,7-di-tthiophen-2-yl-2,3-dihydro-thieno[3,4- d]pyridazine-1,4-dione (TTT-Lum) and 5,7-di-ethylenedioxythiophene-2-yl-2,3-dihydro-thieno[3,4- d]pyridazine-1,4-dione (ETE-Lum). The materials synthesized in the form of donor-acceptor-donor exhibit both KL and EKL properties, which makes them promising candidates in the analytical chemistry and forensic science. Compounds were polymerized successfully without oxidizing pyridazine ring via electrochemical polymerization (only neat BF3-Et2O solution or 0.1 M LiClO4 or 0.1 M tetrabutylammonium perchlorate dissolved in acetonitrile containing 5% of BF3-Et2O by volume ) and the electrochemical and optical properties were investigated. Electroactive and electrochromic polymeric materials, exhibiting reversible redox behaviours, have lower band gaps between 1.6 and 1.7 eV. Also, the polymer films are very stable; the electroactivity and the EKL properties were remain unchangeable after many cycles. Furthermore, the soluble polymer films in alkali medium with their KL properties will attract many attention in the academic areas.