Crystallization‐Induced Enhanced Electrochemiluminescence from a New Tris(bipyridine)ruthenium(II) Derivative

Abstract

Classic tris(bipyridine)ruthenium(II) complex (Ru‐bpy) with high electrochemiluminescence (ECL) efficiency still suffers from a serious aggregation‐caused quenching (ACQ) problem, which greatly weakens its ECL efficiency to restrict further applications in solid‐state ECL imaging and light‐emitting devices. Herein, the crystallization‐induced enhanced ECL (CIE‐ECL) of tris(bipyridine)ruthenium(II) derivatives (Ru‐TPE) are reported by decorating Ru‐bpy with inherent aggregation‐induced emission active tetraphenylethene (TPE), which effectively eliminates the detrimental π–π stacking interactions and thus helps Ru‐bpy surmount notorious ACQ effect in the aqueous phase. The Ru‐TPE shows negligible ECL emission in solution but produces a strong ECL emission upon crystallization. Surprisingly, the ECL efficiency of Ru‐TPE crystals is 20 and 3 times higher than that of its solution and Ru‐bpy crystals, respectively. Experimental and structural analysis reveals that such a CIE‐ECL effect originates from the restricted intramolecular rotation and ordered molecular packing. Moreover, the high‐resolution ECL imaging of a single Ru‐TPE crystal is successfully demonstrated. This work provides a new design strategy for achieving high efficiency in solid‐state ECL imaging and devices.

Precise Modulation of Intramolecular Aggregation‐induced Electrochemiluminescence by Tetraphenylethylene‐based Supramolecular Architectures

“…The emission spectrum of excimer emission is relatively broad, thus resulting in wider red‐shifted peaks in ECL spectra [27] . The four architectures with different stacking patterns exhibited similar ECL emissions, and their substantially red‐shifted ECL peaks indicated that the excited states in different stacking patterns might be governed by the mechanism of surface state transitions with lower energy rather than the band gap [19b,28] . In addition, the results were influenced by analyte concentration as well as instrument slit width and resolution [29] .…”

Aggregation‐Induced Enhanced Electrochemiluminescence from Tris(bipyridine)ruthenium(II) Derivative Nanosheets for the Ultrasensitive Detection of Human Telomerase RNA

“…As shown in Figure S2 in the Supporting Information, an obvious diffraction peak at 12.381°corresponding to the preferential (140) growth plane was observed in the X-ray diffraction (XRD) pattern of Ru-TPE NSs, which was consistent with its simulated signals and Ru-TPE aggregates without bovine serum albumin (BSA). [36] Meanwhile, no new diffraction peaks were detected in the XRD pattern of NSs. The results indicated that BSA may serve as the capping agent to wrap on the Ru-TPE NSs and not participate in the crystallization process to achieve new crystals.…”

“…In the previous work, our group reported the visual ECL imaging of a new TPE-decorated tris(bipyridine)ruthenium(II) derivative crystal (Ru-TPE crystal). [36] Nevertheless, the Ru-TPE crystal cannot be suitable for biological assays and clinical applications in the ECL realm because of its large block size and poor dispersibility (Figure S1, Supporting Information). Herein, the ultrathin Ru-TPE nanosheets (Ru-TPE NSs) were obtained by a protein-assisted self-assembly strategy, which exhibited unique AIECL property and good water-dispersion.…”

Materials for Electrochemiluminescence: TADF, Hydrogen‐Bonding, and Aggregation‐ and Crystallization‐Induced Emission Luminophores

“…More recently, Zhu and co-workers created a [Ru(bpy) 3 ] 2 + derivative Ru-TPE, incorporating the AIE-active tetraphenylethene (TPE) group. [44] The resulting compound exhibited strong CIECL driven by the TPE group that overcame the inherent ACQ nature of [Ru(bpy) 3 ] 2 + . The authors observed an increased crystallinity of the Ru-TPE crystals compared to plain crystals of [Ru(bpy) 3 ] 2 + , confirmed by pXRD measurements.…”