Strongly Chemiluminescent Acridinium Esters under Neutral Conditions: Synthesis, Properties, Determination, and Theoretical Study

Abstract

Various novel acridinium ester derivatives having phenyl and biphenyl moieties were synthesized, and their optimal chemiluminescence conditions were investigated. Several strongly chemiluminescent acridinium esters under neutral conditions were found, and then these derivatives were used to detect hydrogen peroxide and glucose. Acridinium esters having strong electron-withdrawing groups such as cyano, methoxycarbonyl, and nitro at the 4-position of the phenyl moiety in phenyl 10-methyl-10λ-acridine-9-carboxylate trifluoromethanesulfonate salt showed strong chemiluminescence intensities. The chemiluminescence intensity of 3,4-dicyanophenyl 10-methyl-10λ-acridine-9-carboxylate trifluoromethanesulfonate salt was approximately 100 times stronger than that of phenyl 10-methyl-10λ-acridine-9-carboxylate trifluoromethanesulfonate salt at pH 7. The linear calibration ranges of hydrogen peroxide and glucose were 0.05-10 mM and 10-2000 μM using 3,4-(dimethoxycarbonyl)phenyl 10-methyl-10λ-acridine-9-carboxylate trifluoromethanesulfonate salt at pH 7 and pH 7.5, respectively. The proposed chemiluminescence reaction mechanism of acridinium ester via a dioxetanone structure was evaluated via quantum chemical calculation on density functional theory. The proposed mechanism was composed of the nucleophilic addition reaction of hydroperoxide anion, dioxetanone ring formation, and nonadiabatic transition due to spin-orbit coupling around the transition state (TS) to the triplet state (T) following the decomposition pathway. The TS which appeared in the thermal decomposition would be a rate-determining step for all three processes.

Photoinduced Betaine Generation for Efficient Photothermal Energy Conversion

“…Data of 3 at pH 12 are not shownb ecause 3 decomposesatp H12. [22] It was reportedt hat the intermolecular reactions of analogousa cridinium derivatives compete with intramolecular eT. Eur.J.2020, 26,2060 -2066 www.chemeurj.org pH values.…”

Mechanistic insights into the efficient intramolecular chemiexcitation of dioxetanones from TD‐DFT and multireference calculations

“…Chemiluminescence is a more general process and can happen with or without a catalyzer. Both chemiluminescent and bioluminescent systems have the advantage of not needing photoexcitation, which diminishes the possibility of autofluorescence arising from the background signal . The absence of photoexcitation also eliminates problems associated with light penetration into biologic tissue.…”

“…Dioxetanone (Scheme ) is responsible for chemiexcitation in several bioluminescent (such as Coelenterazine, Cypridina luciferin, the fireflies, the earthworm Fredericia heliota , and Latia luciferin) and chemiluminescent systems (such as acridinium esters and 2‐coumaranones) . Two mechanisms have been proposed to explain the efficient S 0 →S 1 chemiexcitation.…”

Enhancement effect on the chemiluminescence of acridinium esters under neutral conditions

“…Compounds 1–8 (Table ) were synthesized as described previously . CTAB, phenol, phenolphthalein, hydrogen peroxide (30% aqueous solution) and horseradish peroxidase were purchased from Wako Pure Chemical Industries (Osaka, Japan).…”

“…Finally, CL compounds may be used under physiological condition in vivo . Recently, we synthesized various acridinium ester derivatives, studied their properties and found several acridinium esters had strong CL intensity under neutral conditions . We focus on the enhancement of CL intensity under neutral conditions.…”