Revealing Crystallization‐Induced Blue‐Shift Emission of a Di‐Boron Complex by Enhanced Photoluminescence and Electrochemiluminescence

Abstract

Elucidating the effects of crystallization‐induced blue‐shift emission of a newly synthesized di‐boron complex (DBC) by enhanced photoluminescence (PL) and electrochemiluminescence (ECL) in the annihilation pathway was realized for the first time. The 57 nm blue‐shift and great enhancement in the crystalline lattice relative to the DBC solution were attributed to the restriction of intramolecular rotation (RIR) and confirmed by PL imaging, X‐ray diffraction, as well as DFT calculations. It was discovered that ECL at crystalline film/solution interfaces can be further enhanced by means of both co‐reactant route and RIR. The RIR contributions with co‐reactant increased ECL up to 5 times more. Very interestingly, the co‐reactant system was found to give off a red‐shifted light emission. Mechanistic studies reveal that a difference between location of the ECL in the co‐reactant route and that in the annihilation pathway leads to an alternative emission wavelength.

Photoluminescence and electrochemiluminescence of thermally activated delayed fluorescence (TADF) emitters containing diphenylphosphine chalcogenide-substituted carbazole donors

“…Furthermore, high luminophore concentrations, and film electrodes 61 in ECL studies can mimic bulk and interfacial molecular conditions in OLEDs, allowing predictions of molecular performance before full device manufacturing. ECL finds additional applications in discovering luminophore film enhancement phenomena, [69][70][71] and in commercial applications for antigen sensing. 72 Since the early studies on ECL in the 1960s, [73][74][75] various types of emissive compounds have been studied.…”

Intrareticular charge transfer regulated electrochemiluminescence of donor–acceptor covalent organic frameworks

“…E lectrochemiluminescence (ECL) is a light-emitting process involving excited state generation through an electrochemical reaction 1,2 . The ECL efficiency mainly depends on the charge transfer between the emitters and the coreactant/emitter 3,4 . In most cases, the emitters such as small molecules and nanocrystals are transformed into excited states through an intermolecular charge transfer process [5][6][7][8][9] .…”

Lighting up Electrochemiluminescent Inactive Dyes by Intramolecular Resonance Energy Transfer

“…Current available ECL emitters mainly include metal complexes, [10][11][12] semiconducting nanoparticles/nanoclusters, [13][14][15][16] conjugated organic molecules [17][18][19] . Great efforts of modulating electron transfer among electrode, emitters and/or co-reactants by potential control, [20][21][22][23][24] aggregation-induction, [25][26][27][28][29] self-enhancement, [30][31][32][33][34] crystallization, [35][36][37][38] as well as other strategies, [39][40][41][42] have been devoted to improving ECL efficiency and adapting to different application schemes. Despite these unprecedented success in mechanism studies and some applications, [43][44][45][46] developing ECL emitters with reasonable ECL efficiency, good water-solubility/-dispersibility, and facile being labeled is still in infancy.…”