Circularly Polarized Phosphorescence from Cocrystallization of Atomic Precise Silver Nanoclusters with Tartaric Acid

Abstract

Recently, chirality was successfully introduced to rare earth complexes, which have long afterglow phosphorescence, by ball-milling with l/d-cysteine, leading to CPP with a dissymmetry factor (g lum ) up to 10 −2 . [16] CPP from multiple metal centers has also been achieved by the preparation of a homochiral metal-organic framework. [17] Despite these fantastic examples, the candidates for creating CPP are still limited. New candidates with a long lifetime and intrinsic phosphorescence are urgently needed to widen the family of CPP materials and broaden the scope of their applications.Metal nanoclusters (NCs) are intermediates between single-metal complexes and metal nanoparticles. [18,19] Metal NCs, especially those formed by the complexation of metal ions with organic ligands, could have atomic precision proved by single-crystal X-ray diffraction analysis. Their photoluminescence is normally weak in dilute dispersions or amorphous state, which is disadvantageous for the construction of CPP materials. However, this drawback could be overcome by lowering the temperature or forcing them to form highly ordered supramolecular structures. [20] In the latter case, in most cases, the emission is characterized by a relatively long lifetime of microseconds that could be assigned to phosphorescence in nature. For the chirality which is another necessity to induce CPP, chiral organic ligands were routinely adopted during the preparation of the metal NCs. [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] Based on these efforts, a few metal NCs that exhibit CPP in solid states have been successfully created, including gold, [27][28][29] silver, [30,31] and copper [32][33][34][35] NCs.In terms of the chirality of a given system, the building blocks are unnecessarily chiral, which has been confirmed by chiral supramolecular self-assemblies formed by achiral organic molecules, such as those with C 3 -symmetry. [36][37][38] However, this rule has not been demonstrated for metal NCs until very recently. [39] The breakthrough came from the assembly of watersoluble silver NCs ((NH 4 ) 9 [Ag 9 (mba) 9 ], H 2 mba = 2-mercaptobenzoic acid, abbreviated to Ag 9 -NCs hereafter), which were facilely obtained by coordination of Ag(I) with 2-mercaptobenzoic acid (H 2 mba) in water in the presence of ammonia-water (Figure 1a). Single-crystal X-ray diffraction analysis showed each cluster has a core of nine Ag(I) ions that resembles a triangular prism comprising three Ag 3 trigons. The cluster has a C 3 axis that passes Recently, advanced optical materials with circularly polarized phosphorescence (CPP) have attracted much attention. However, such materials are limited due to the difficulty of preparation and the scarcity of precursors. Herein, CPP materials are constructed for the first time using water-soluble, pseudo-chiral silver nanoclusters with atomic precision ((NH 4 ) 9 [Ag 9 (mba) 9 ], H 2 mba = 2-mercaptobenzoic acid, abbreviated to Ag 9 -NCs hereafter). Induced by the complexation of l-or d-tartaric acid (TrA) through h...

A multistimulus-responsive self-healable supramolecular copper(ii)-metallogel derived from l-(+) tartaric acid: an efficient Schottky barrier diode

“…2,55 Copper based metallogels have numerous applications like redox activity, 56 proton conductivity, 57 self-healing property, 58,59 catalysis, 60 superconductor, 61 and harmful organophosphate sensing. 62 Currently, researchers are continuously trying to discover new functional materials for energy related applications to meet the worldwide energy demand with energy storage devices, 63,64 energy conversion devices, 65 solar cells, 66,67 low-friction materials, 68,69 corrosiveresistant coating, 70,71 organic photovoltaic devices, [72][73][74][75] photodetectors, 76,77 fuel cells, 78 water splitting, 79 thin-film solar cells, [80][81][82] light-emitting devices, 83 metal-organic gels to nanoclusters, [84][85][86] and so on. In 2012, Dastidar et al published an article on tartaric acid-based ligand-mediated gel materials.…”

In situ synthesis of chiral AuNCs with aggregation-induced emission using glutathione and ceria precursor nanosheets for glutathione biosensing

“…Several reports have revealed that the CD amplification of luminescent nanomaterials could be mainly attributed to an aggregation process. [40][41][42] In our study, the Au(I)-SG complexes demonstrated a high degree of flexibility in the non-aggregate state, leading to significant vibrational and rotational intensities of the synthesized Au(I)-SG oligomers. Conversely, the aggregate state of AuNCs showed inter-and intra-cluster aurophilic interactions coupled with intramolecular H-bonds that could efficiently restrict the vibrational and rotational transitions of the chiral GSH ligands, and thus the CD signals were highly amplified.…”

Luminescence Enhancement of a Gold Nanocluster Hydrogel Facilitated by Water for Erasable Water Writing and Visual Solvent Differentiation

“…Gold nanoclusters (AuNCs) represent a prominent class of organic–inorganic composite materials. − The unique photoluminescence (PL) properties of AuNCs, such as phosphorescence, size-dependent luminescence, and long wavelength (red/near-infrared) emission, make them promising candidates in various fields, including chemical sensing, bioimaging, and optoelectronic devices. − However, the low quantum yield (QY) restricts their practical applications. Moreover, various tuning strategies to improve the emission properties of AuNCs, enhance the electron density of thiolate ligands, regulate the polarity of solvents, and regulate the ratio of metal atoms to ligands or co-assembly with other molecules have been successfully proposed. − Those strategies could overcome the drawbacks, and materials with a relatively long lifetime of microseconds assigned to phosphorescence can be obtained.…”