Synthesis, Electrochemistry, and Electrogenerated Chemiluminescence of Two BODIPY-Appended Bipyridine Homologues

Abstract

Two new 2,2’-bipyridine (bpy) derivatives containing ancillary BODIPY chromophores attached at the 5- and 5’-positions (BB3) or 6- and 6’-positions (BB4) were prepared and characterized. In this work, the basic photophysics, electrochemistry and electrogenerated chemiluminescence (ECL) of BB3 and BB4 are compared with those previously reported for a related bpy-BODIPY derivative (BB2) (J. Phys. Chem. C 2011, 115, 17993–18001). Cyclic voltammetry revealed that BB3 and BB4 display reversible 2e− oxidation and reduction waves, which consist of two closely spaced (50 – 70 mV) 1e− events. This redox behavior is consistent with the frontier molecular orbitals calculated for BB3 and BB4 and indicates that the 2,2’-bipyridine spacer of each bpy- BODIPY homologue does not facilitate efficient electronic communication between the tethered indacene units. In the presence of a coreactant such as tri-n-propylamine (TPA) or benzoyl peroxide (BPO), BB3 and BB4 exhibit strong ECL and produce spectra that are very similar to their corresponding photoluminescence profiles. The ECL signal obtained under annihilation conditions, however, is significantly different and is characterized by two distinct bands. One of these bands is centered at ~570 nm and is attributed to emission via an S- or T-route. The second band, occurs at longer wavelengths and is centered around ~740 nm. The shape and concentration dependence of this long-wavelength ECL signal is not indicative of emission from an excimer or aggregate, but rather is suggests that a new emissive species is formed from the bpy-BODIPY luminophores during the annihilation process.

Twisted configuration pyrene derivative: exhibiting pure blue monomer photoluminescence and electrogenerated chemiluminescence emissions in non-aqueous media

“…22 The cyclic voltammograms of MB-Py and Bz-Py at more positive potentials (Fig. S-2 †) showed that both the derivatives produced a second irreversible oxidation wave at +1.72 V and +1.59 V vs. SCE, respectively, which are frequently observed for the dications.…”

Light-driven generation of hydrogen: New chromophore dyads for increased activity based on Bodipy dye and Pt(diimine)(dithiolate) complexes

“…A silver wire was used as the quasi-reference electrode and calibrated against ferrocene. All redox potentials are reported vs. the Fc/Fc + couple that has a value of 0.40 V vs. SCE with SCE = 0.24 relative to NHE (50,(53)(54)(55)(56)(57). The cyclic voltammograms of the Pt(diimine)(bdt) complexes 1(bpyC) and 1(bpyP) each exhibit two reversible reductions in the ranges between −1.39 V to −1.41 V and −1.9 V to −2.03 V, as well as two irreversible oxidations in the range 0.04-0.54 V (Fig.…”

Imaging Analysis Based on Electrogenerated Chemiluminescence

“…Apart from these so-called mixed ECL systems, colorchangeable ECL emission from a single chemical species has also been reported, usually resulting from either formation of an emissive excimer [110] or from emissive products of chemical or electrochemical side reactions [31,111,112]. For example, an unusual ECL behavior of fac-tris [5-(4-…”