Stimuli-Induced Reversible Transformation between Decanuclear and Pentanuclear Gold(I) Sulfido Complexes

Abstract

Decanuclear and pentanuclear gold(I) sulfido complexes of phenanthrene-and dibenzothiophene-based diphosphine ligands were synthesized and characterized. Unprecedented stimuli-induced reversible transformation between decanuclear and pentanuclear gold(I) sulfido complexes was observed, which could be readily monitored by NMR and UV−vis absorption spectroscopy in solution. Remarkably, the decanuclear gold(I) sulfido complex (Au 10 -L Ph ) was found to show a highly reversible transformation process, which is stable for over 10 successive cycles in solution. The stimuli-induced reversible transformation behavior of the gold(I) sulfido complexes was found to depend on the P−P bite distance of the bidentate phosphine ligands.

Metallo-Supramolecular Hexagonal Wreath with Four Switchable States Based on a pH-Responsive Tridentate Ligand

“…The in situ deprotonation/oxidation from S1 -Co­(II) to S3 -Co­(III) was further characterized by 1 H NMR spectroscopy, as shown in Figure . Compared with the spectrum of H 8 LB (Figure a), after the complexation with paramagnetic Co­(II) ion, the proton signals on H 2 DAP moieties of S1 -Co­(II) all shifted downfield dramatically to 40–100 ppm (Figures b and S40), strongly proving the formation of ⟨H 2 DAP–Co­(II)–H 2 DAP⟩ 2+ junctions, owing to the existence of unpaired electrons in Co­(II) complexes. ,, After being treated with a stoichiometric amount of NaOH for less than 5 min, the N–H peaks disappeared in the 1 H NMR spectrum of the resulting complex, and all peaks on DAP moieties shifted back to the aromatic region with the diamagnetic feature (Figures c and S41–S43). These results indicate the formation of ⟨DAP–Co­(III)–DAP⟩ – with only diamagnetic metal ions along with the loss of acidic protons.…”

“…In recent years, while the complexity of synthetic metallo-supramolecular systems has constantly been pursued by advancing coordination-driven self-assembly, numerous efforts have also been made to manipulate the ensembles among different states based on their dynamic nature, to achieve the properties and functions comparable to biological systems. − To date, the following strategies have been employed to switch the states of ensembles: (i) postassembly isomerization of building blocks triggered by light, redox processes, or intermolecular cycloaddition reactions; (ii) tuning the valence states of metal ions by reductant/oxidant or via electrochemical pathways; (iii) mediating the coordination states of ligands through acid–base reactions; (iv) conducting geometrical interconversions of the constructs via encapsulating and releasing guest molecules or through altering the concentration or temperature of the assembly solution . However, only very few examples can possess multiple states with distinct properties and functions, without losing structural integrity.…”

Recent Advances in Ligand Engineering for Gold Nanocluster Catalysis: Ligand Library, Ligand Effects and Strategies

“…Robustness of Au 8 (PNP) 4 was proved by the complete recovery of catalyst after reaction. Such ligand was also applied to produce Au 17 Cd 2 (PNP) 2 (SR) 12 for the KA 2 reaction by the same group, [93] in which the nitrogen site is also suspicious in the activation of substrates. Interestingly, for the other multidentate ligands such as Ph-form mentioned in section 2, the pyridyls were able to coordinate to the surface gold; however, the CH 2 units in PNP prevented the N donors to contact with gold.…”

“…Recent advances in ligated atomically precise AuNCs and their structure-property relationships demonstrated that ligand effects are ubiquitous in their stability, [5] chirality, [6,7] photoluminescence, [8,9] catalysis, [10] and the others. [11,12] The synthesis, characterization and general properties of AuNCs based on different ligands have been nicely reviewed by Jin, [13] Andersson [14] and Wang [15] for thiols, phosphines and alkynes respectively. NHC functionalized nanomaterials have also been excellently summarized by Cathleen.…”

Photo- and Temperature-Induced Reversible Structural Transformation between Dodecanuclear and Pentadecanuclear Gold(I) Sulfido Complexes

“…It was only until 2015 that our group reported the first successful construction of a photo-induced isomerization-driven cluster-to-cluster transformation system by the employment of cis – trans photoisomerization properties (Scheme ). Since the geometries of gold­(I) sulfido complexes are found to be highly sensitive to the ligand shape and topology, this has provided a rational approach to regulate the geometry of gold­(I) sulfido complexes. − In addition, mono- and di-phosphine ligands are commonly employed to construct polynuclear gold­(I) sulfido complexes, while the use of tri-phosphine ligands is much less explored . Thus, the exploration of tri-phosphine ligands for the assembly of polynuclear gold­(I) sulfido complexes is worth pursuing, which may potentially lead to unprecedented architectures of polynuclear gold­(I) sulfido complexes with attractive luminescence and stimuli-responsive properties.…”