Multistimuli-Responsive Fluorescent Organometallic Assemblies Based on Mesoionic Carbene-Decorated Tetraphenylethene Ligands and Their Applications in Cell Imaging

Abstract

The controllable construction of light-emitting organometallic supramolecular materials integrating stimulus responses and biological applications is still a major challenge today. In this work, emissive organometallic assemblies based on Ag I /Au I and mesoionic carbene-decorated tetraphenylethene (MIC-TPE) ligands have been synthesized and characterized. Photophysical studies showed that these organometallic assemblies [M 4 (2) 2 ](OTf) 4 not only fluoresce in various dilute solutions, resulting from the rigidification of MIC-TPE ligands upon complexation, but also show tunable fluorescence wavelengths and intensity behaviors in mixed solvent systems and at varying temperatures while in solution, and mechanical pressure stimulus-responsive fluorescent features in the solid state. Furthermore, the organometallic cages [M 4 (2) 2 ](OTf) 4 (M = Ag and Au) were successfully employed for cell imaging and showed the potential of anticancer activity, making them promising candidates for cancer theranostics. This work provides a simple and efficient method to prepare highly emissive and stimulus-responsive organometallic materials and paves the way for related biological applications such as cancer cell imaging and targeted therapy.

Synthesis, Characterization, and Structural Transformation of Picolyl-Functionalized Polynuclear Silver(I)– and Gold(I)–N-Heterocyclic Carbene Complexes

“…Moreover, the disappearance of the imidazolium N– CH –N proton at δ 9.00 ppm was observed in the 1 H NMR spectrum upon metalation (Figure a), together with the appearance of the typical resonance at δ 182.0 ppm for Ag I -bound carbene carbon atoms in the 13 C­{ 1 H} NMR spectrum (Figure S6). The shifts were in accord with those in the reported Ag I –NHC complexes. , Unexpectedly, the discrete trinuclear carbene complex [Ag 3 L 2 ]­(PF 6 ) 3 was generated rather than a [Ag 2 L 2 ]-type complex. Initial evidence for the generation of species of composition [Ag 3 L 2 ]­(PF 6 ) 3 was based on an ESI-MS analysis (Figure b and Figure S10), which exhibited the highest intensity peaks at m / z 821.1560 (calcd for {[Ag 3 L 2 ]­(PF 6 )} 2+ 821.1454) with isotopic patterns corresponding to the formula [Ag 3 L 2 ]­(PF 6 ) 3 .…”

“…The shifts were in accord with those in the reported Ag I −NHC complexes. 46,47 Unexpectedly, the discrete trinuclear carbene complex [Ag 3 L 2 ](PF 6 ) 3 was generated rather than a [Ag 2 L 2 ]-type complex. Initial evidence for the generation of species of composition [Ag 3 L 2 ](PF 6 ) 3 was based on an ESI-MS analysis (Figure 1b and Figure S10), which exhibited the highest intensity peaks at m/z 821.1560 (calcd for {[Ag 3 L 2 ](PF 6 )} 2+ 821.1454) with isotopic patterns corresponding to the formula [Ag 3 L 2 ](PF 6 ) 3 .…”

Perylene Diimide-Based Multicomponent Metallacages as Photosensitizers for Visible Light-Driven Photocatalytic Oxidation Reaction

“…[12][13][14][15][16][17][18][19] This strategy takes the highly directional metal-coordination bonds to prepare SCCs spontaneously and endows the SCCs with high structural and functional diversity. [20][21][22][23][24][25][26][27][28] Especially, the preparation of photosensitizers using this method not only avoids their self-aggregation through the formation of geometric structures, but also facilitates the intersystem crossing owing to the introduction of heavy metal atoms, giving high 1 O 2 generation ability and photostability. [29][30][31][32][33][34] Moreover, different buliding blocks capable of generating 1 O 2 can be integrated into a single metallacage.…”

N-heterocyclic carbene-stabilized metal nanoparticles within porous organic cages for catalytic application

“…Compared to the imidazolium counterparts, replacing a carbon atom with an electronegative nitrogen atom can result in 1,2,4-triazolium moieties bearing different steric and electronic environments [ 34–38 ]. However, to the best of our knowledge, the preparation of MNPs stabilized by 1,2,4-triazolium-derived NHCs has rarely been explored [ 28 ].…”