title: Electrogenerated chemiluminescence of platinum(II) alkynyl terpyridine complex with peroxydisulfate as coreactant.
abstract: A Pt(II) alkynyl terpyridine complex containing a carbazole moiety, [Pt((t)Bu(3)tpy)(C≡C-C(6)H(4)-4-carbazole-9)](+) ((t)Bu(3)tpy = 4,4',4''-tri-tert-butyl-2,2':6',2''-terpyridine) 1, has been synthesized and characterized. The photophysical behavior has been studied, and the molecular structure has been determined by X-ray crystallography. The complex was found to exhibit intense electrogenerated chemiluminescence (ECL) using peroxydisulfate (S(2)O(8)(2-)) as coreactant in acetonitrile/water (1-25%, v/v) mixture at both glassy carbon and gold electrodes, representing the first ECL example of the Pt(II) alkynyl family. The ECL was produced at potential corresponding to the first reduction wave (-0.90 V vs SCE), significantly shifted by ∼0.65 V toward more positive potential compared with that of [Ru(bpy)(3)](2+) (bpy = 2,2'-bipyridine). The ECL spectrum was found to be identical to the photoluminescence spectrum recorded in the same medium, indicating the formation of the same excited state of dπ(Pt) → π*((t)Bu(3)tpy) (3)MLCT mixed with π(C≡CR) → π*((t)Bu(3)tpy) (3)LLCT in both cases. The ECL mechanism was proposed involving the formation of the strongly oxidizing intermediate, SO(4)(•-), mainly generated during the catalytic reduction of S(2)O(8)(2-) by the electrogenerated 1(-). Chemiluminescence of 1/S(2)O(8)(2-) based on reduction with Al metal is also described.
authors.affiliation: Institute of Molecular Functional Material and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, PR China.
authors.forename: Zuofeng
authors.initials: Z
authors.lastname: Chen
authors.forename: Keith Man-Chung
authors.initials: KM
authors.lastname: Wong
authors.forename: Eric Chi-Ho
authors.initials: EC
authors.lastname: Kwok
authors.forename: Nianyong
authors.initials: N
authors.lastname: Zhu
authors.forename: Yanbing
authors.initials: Y
authors.lastname: Zu
authors.forename: Vivian Wing-Wah
authors.initials: VW
authors.lastname: Yam
mesh_terms: D018360:Crystallography, X-Ray; D004563:Electrochemistry; D049449:Luminescence; D008958:Models, Molecular; D015394:Molecular Structure; D009944:Organoplatinum Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010545:Peroxides / Q000737:chemistry*; D013431:Sulfates / Q000737:chemistry*
chemical_list: D009944:Organoplatinum Compounds; D010545:Peroxides; D013431:Sulfates