title: TEMPO-functionalized zinc phthalocyanine: synthesis, magnetic properties, and its utility for electrochemical sensing of ascorbic acid.
abstract: Zinc(ii) phthalocyanine (TEMPO-ZnPc), peripherally functionalized with 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) radicals is synthesized and its magneto structural and electrochemical behaviors are investigated. TEMPO-ZnPc shows multi-electron ring based reduction reactions and a TEMPO based oxidation reaction. Spectroelectrochemical measurements support these peak assignments. TEMPO-ZnPc is tested as a homogeneous and heterogeneous ascorbic acid (AA) sensor. Disappearance of TEMPO-ZnPc based reduction processes and the observation of new waves at around 0 and 1.20 V with respect to increasing AA concentration indicate the interaction of TEMPO-ZnPc with AA and usability of the complex as an electrochemical AA sensor. For practical usage as heterogeneous electrocatalysts for AA sensing, a glassy carbon electrode (GCE) is coated with TEMPO-ZnPc (GCE/TEMPO-ZnPc) and this modified electrode is tested as a heterogeneous AA sensor. The redox peak of GCE/TEMPO-ZnPc at 0.81 V decreases the peak current while a new wave is observed at 0.65 V during the titration of the electrolyte with AA. GCE/TEMPO-ZnPc sense AA with 1.75 × 10(-6) mol dm(-3) LOD with a sensitivity of 1.89 × 10(3) A cm mol(-1).
authors.affiliation: Department of Chemistry, Yıldız Technical University, 34210, Davutpaşa, İstanbul, Turkey. mkasimsener@gmail.com.
authors.forename: Sibel Eken
authors.initials: SE
authors.lastname: Korkut
authors.forename: Duygu
authors.initials: D
authors.lastname: Akyüz
authors.forename: Kemal
authors.initials: K
authors.lastname: Özdoğan
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Yerli
authors.forename: Atıf
authors.initials: A
authors.lastname: Koca
authors.forename: M Kasım
authors.initials: MK
authors.lastname: Şener
mesh_terms: D001205:Ascorbic Acid / Q000032:analysis*; D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry*; D003497:Cyclic N-Oxides / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D007211:Indoles / Q000737:chemistry*; D054833:Isoindoles; D008280:Magnetics; D015394:Molecular Structure; D010084:Oxidation-Reduction
chemical_list: D056831:Coordination Complexes; D003497:Cyclic N-Oxides; D007211:Indoles; D054833:Isoindoles; D001205:Ascorbic Acid; C013647:phthalocyanine; C003959:TEMPO