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.

Synthesis, structure and characterization of Fe6molecular clusters with peripheral sulfur atom-capped silver nanoparticles

“…27 The current enhancement could be interpreted by kinetically slow reduction of the Fe 6 complex at the Au surface. 28 However, after repetitive scans (>9 cycles), significant current enhancement was observed at 0.70 V (curve b in Fig. 6), probably due to decomposition of the Fe 6 complex on the electrode surface.…”

Ligand-Localized Triplet-State Photophysics in a Platinum(II) Terpyridyl Perylenediimideacetylide

“…22,28,73,76 However, incorporation of a strong-field acetylide ligand shifts the deactivating ligand field states higher in energy, rendering these compounds emissive in room-temperature solutions. This trivial manipulation of photophysical properties renders such molecules promising chromophores for optical power limiting, 24,29,31,32,52 singlet oxygen photosensitization, 39,40 photocatalytic hydrogen production, 24,[41][42][43][44][45]71 luminescence sensing, 7,24,25,34,[46][47][48][49][50]72 electrogenerated chemiluminescence, 66 dye-sensitized solar cells, 67 biolabeling, 1,12,24,35 photoinduced charge separation (artificial photosynthesis), 38 and DNA metallointercalation. 56 Growing interest in the development of photovolatics and solar fuels catalysis requiring visible-absorbing chromophores with high oscillator strength has led to perylenediimides (PDI) being incorporated into transition metal complexes in a variety of formats.…”

A Solid-state Electrochemiluminescence Sensor for Detecting Glutathione with a Graphite-phase Carbon Nitride/Silica Modified Glassy Carbon Electrode

“…While the pH value was higher than 7.5, the SO4 •-would be consumed by OH -, and • OH would be further generated. 35,36 Thus, the pH 7.5 was applied here as it exhibited the highest ECL intensity.…”