Radical-Triggered Chemiluminescence of Phenanthroline Derivatives: An Insight into Radical–Aromatic Interaction

Abstract

The hitherto unknown influence of 1,10-phenonthroline (1,10-phen) and its derivatives on the weak chemiluminescence (CL) of periodate-peroxide has been investigated, and a novel method for CL catalysis is described. Herein, we have deconvoluted the variation in CL intensity arising from the addition of various derivatives of 1,10-phen. Interestingly, similar derivatives of 1,10-phen show interesting differences in their reactivity toward CL. Electron-withdrawing substituents on 1,10-phen boosted the CL signals, indicating a negative charge buildup on 1,10-phen in the rate-determining step. The 1,10-phen derivatives having substitution at the C5=C6 position resulted in no CL signals due to the blockage of the reactive site. Mechanistic investigations are interpreted in terms of free radical (H2O2 reaction), followed by the oxygen atom transfer via an electrophilic attack of IO4– (IO4– reaction) on 1,10-phen resulting in dioxetane with enhanced CL emission. Additionally, the relationship between electronic structures and photophysical properties was investigated using density functional theory. Our results are expected to open up promising application of 1,10-phen as a molecular catalyst, providing a new strategy for metal-free catalytic CL enhancement reaction. We believe that this would foster in gleaning more detailed information on the nature of these reactions, thereby leading to a deeper understanding of the CL mechanism.

Direct and Indirect Chemiluminescence: Reactions, Mechanisms and Challenges

“…It has been reported that 1,10-phenanthroline dioxetanes enhance light emission in respect to the IO 4 − -H 2 O 2 system alone. The proposed radical-based mechanism involves the C 5 =C 6 bond of 1,10-phenanthroline that is initially attacked by HO • , leading to a dioxetane intermediate responsible for the CL emission (Scheme 8) [86]. The CL of the IO 4 − /peroxide system and the factors influencing the emission have been recently reviewed elsewhere [87].…”

Long‐lasting chemiluminescence by aggregation‐induced emission surfactant with ultralow critical micelle concentration

“…As displayed in Figure S8, p ‐benzoquinone (HQ) and thiourea caused visible CL suppression, while NaN 3 induced slight CL decrease, suggesting the primary ROS were superoxide radical (O 2 •− ) and hydroxyl raidical ( • OH). [ 45–47 ] The electron paramagnetic resonance (EPR) results also demonstrated the continuous generation of O 2 •− and • OH during the CL reaction. As shown in Figure 4, the sextuple peaks (∼2:2:1:2:1:2) located at 3477, 3487, 3492, 3502, 3506, and 3517 G values, are attributed to the characteristic O 2 •− EPR signals.…”

“…•− ) and hydroxyl raidical ( • OH). [45][46][47] The electron paramagnetic resonance (EPR) results also demonstrated the continuous generation of O 2…”

Wavelength‐Tunable, Long Lifetime, and Biocompatible Luminescent Nanoparticles Based on a Vitamin E‐Derived Material for Inflammation and Tumor Imaging

“…OVE was synthesized by a facile and one-step coupling reaction between oxalyl chloride and VE (Figure S2a, Supporting Information). The final product was structurally characterized with 1 H and 13 C NMR spectroscopy, high-resolution mass spectrometry, and Fourier transform infrared (FT-IR) spectrometry (Figure S2b-e, Supporting Information), demonstrating successful synthesis of OVE with the expected structure. Of note, OVE can be easily dissolved in common organic solvents, such as acetone, tetrahydrofuran (THF), n-hexane, dichloromethane (DCM), chloroform, dimethyl sulfoxide, and dimethylformamide (DMF), which is beneficial for manufacturing diverse platforms.…”

“…Thus far, transition metal complexes, [6] porous silicon nanoparticles, [7] carbon nanodots, [8] Schaap's adamantylidenedioxetane, [9] semiconducting polymers, [10] fluorophore/peroxalate ester systems, [11] materials containing luminol and its derivatives, [12] phenanthroline derivatives, [13] fluoresceinyl cypridina luciferin analog, [14] luciferase-luciferin pairs, [5d] and tyrosine-derived materials, [15] have been developed as different types of luminescent materials for a diverse array of applications. As well documented, overproduction of reactive oxygen species (ROS) in inflammatory cells (such as neutrophils and macrophages) is a common feature of both inflammatory and oxidative stress responses.…”