A series of amphiphilic platinum(II) complexes with tridentate N-donor ligands has been synthesized and characterized. Different supramolecular architectures are constructed using the amphiphilic ...molecules as the building blocks through the formation of Pt···Pt and π–π stacking interactions in aqueous media. The aggregation–deaggregation–aggregation self-assembly behavior together with obvious spectroscopic changes could be fine-tuned by the addition of THF in aqueous media. More interestingly, one of the complexes is found to show fast response and high selectivity toward alcohol and water vapors with good reversibility, leading to drastic color and luminescence changes, and hence unique dual switching behavior, with the water molecules readily displaced by the alcohol vapor. Rapid writing and erasure have been realized via the control of a jet or a stream of alcohol vapor flow. In addition, it has been employed as active materials in the fabrication of small-molecule solution-processable resistive memory devices, exhibiting stable and promising binary memory performance with threshold voltages of ca. 3.4 V, high ON/OFF ratios of up to 105 and long retention times of over 104 s. The vapochromic and vapoluminescent materials are demonstrated to have potential applications in chemosensing, logic gates, VOC monitoring, and memory functions.
A series of bipyridine platinum(II) complexes with different sizes of triangular metallacycles and alkyl/oligoether chains has been synthesized and characterized. They are packed in a zig‐zag fashion ...with the formation of dimeric structures according to their X‐ray crystal structures. Different emission origins are observed due to the different sizes of the triangular ligands. Their morphologies could be tuned by the modification of the molecular structures with different metallacyclic alkynyl ligands and alkyl/oligoether chains and solvents. More interestingly, unusual electronic absorption changes and upfield shifts of the aromatic proton resonances are observed upon increasing the temperature, suggesting further aggregation of the architectures. Near‐infrared (NIR) emission is also realized through the tuning of the π–π stacking, Pt⋅⋅⋅Pt interactions, and the packing of planar metallacycles.
Triangle of light! A series of bipyridine platinum(II) complexes with different sizes of triangular metallacycles and alkyl/oligoether chains demonstrates that the emission origin is dependent on the size of triangular metallacycles. Their aggregation behaviors are induced by solvents and promoted by temperature. NIR emission is realized due to the formation of the strong π–π stacking and Pt⋅⋅⋅Pt interactions induced by the close packing of the planar metallacycle.
A thermally activated delayed fluorescence (TADF) tetrametallic Cu(I) metallacycle A behaves as a conformationally adaptive preorganized precursor to afford, through straightforward and rational ...coordination-driven supramolecular processes, a variety of room-temperature solid-state luminescent polymetallic assemblies. Reacting various cyano-based building blocks with A, a homometallic Cu(I) 1D-helical coordination polymer C and Cu8M discrete circular heterobimetallic assemblies D M (M = Ni, Pd, Pt) are obtained. Their luminescence behaviors are studied, revealing notably the crucial impact of the spin–orbit coupling offered by the central M metal center on the photophysical properties of the heterobimetallic D M derivatives.
A series of luminescent polynuclear alkynylgold(I) complexes with different lengths of alkyl chains attached at the N‐heterocyclic carbene moieties has been synthesised and demonstrated to display ...intriguing self‐assembly behaviours through a cooperative growth mechanism. Variation of the alkyl chain length was found to cause drastic morphological differences in the aggregates and to strongly affect the thermodynamic parameters as revealed by the nucleation–elongation model.
Turnover a new leaf: A series of luminescent non‐amphiphilic polynuclear alkynylgold(I) complexes has been synthesised and demonstrated to undergo self‐assembly in a THF–water mixture through a cooperative growth mechanism. Simple modifications of the alkyl chain length were found to cause drastic morphological differences in the aggregates and to strongly affect the thermodynamic parameters of the self‐assembly process (see figure).
A novel class of luminescent phosphole oxide-containing alkynylgold(III) complex has been synthesized, characterized, and applied as active material in the fabrication of solution-processable ...resistive memory devices. Incorporation of the phosphole oxide moiety in gold(III) system has been demonstrated to provide an extra charge-trapping site, giving rise to intriguing ternary memory performances with distinct and low switching threshold voltages, high OFF/ON1/ON2 current ratio of 1/103/107, and long retention time for the three states. The present study offers vital insights for the future development of multilevel memory devices using small-molecule organometallic compounds.
A novel class of luminescent trinuclear alkynylgold(I) complexes with N-alkyl substituted triindole ligands has been synthesized and characterized. They are found to exhibit rich photophysical and ...electrochemical properties. The complexes have been demonstrated to display interesting supramolecular assembly with spherical nanostructures in aqueous THF solution through a cooperative growth mechanism. The self-assembly process is shown to be mediated by the π–π stacking interactions and hydrophobic–hydrophobic interactions of the triindole moieties upon solvent modulation. These gold(I) complexes have been employed as active materials in the fabrication of solution-processable resistive memory devices, showing promising binary memory performances with low switching threshold voltages of ca. 1.5 V, high ON/OFF current ratio of up to 105, long retention time of over 104 s, and excellent stability. The present work opens up a new avenue for the future design of versatile organogold(I) complexes that could serve as multifunctional materials.
The rational design of a new class of photoresponsive tris(8-hydroxyquinolinato)aluminum(III) (Alq3) complexes has been developed. By incorporating the photochromic dithienylethene units with ...different peripheral heterocycles into the Alq3 framework, the photochromic properties as well as photoswitching efficiency can be readily modulated, through effective photocyclization of the Al(III) complex. Such intrinsic photochromic behavior leads to the unprecedented enhancement in the electron-transporting properties as demonstrated by the as-fabricated electron-only device, rendering the realization of photoswitchable electron mobility. In addition, one of these complexes is capable of serving as an active layer for solution-processable resistive memory devices. Photocontrollable memory performance has been achieved with a binary memory behavior, with high ON/OFF ratio and long retention time. This work represents not only the first example of photoresponsive Alq3-based electron-transporting materials but also the solution-processable Alq3-based optical and resistive memory devices with photocontrollable performance.
A new class of phosphole oxide based alkynylplatinum(II) 2,6‐bis(N‐alkylbenzimidazol‐2’‐yl)pyridine (bzimpy) complexes were synthesized and characterized. Their self‐assembly was driven by ...hydrophobic–hydrophobic and π–π stacking interactions. The self‐assembly properties were also investigated by UV/Vis absorption spectroscopy, which revealed that the alkyl‐chain length of the bzimpy moiety and the π‐surface area of the alkynyl ligand have significant influence on the overall self‐assembly process. The alkyl‐chain length also affected the morphological structures of the aggregates, which were studied by transmission electron microscopy and scanning electron microscopy.
Inter‐play time! A new class of phosphole oxide based alkynylplatinum(II) complexes demonstrate tunable self‐assembly properties in aqueous DMSO. Subtle modification of the molecular structure causes morphological changes of the aggregates (see figure).
A class of benzobphosphole‐based alkynylgold(I) complexes has been synthesized and characterized. These complexes share a similar benzobphosphole ligand, in which the phosphole moiety is substituted ...with various π‐conjugated units with different donor strengths, namely phenoxazinylphenyl, tris(di‐tert‐butylcarbazolyl)phenyl and 2,4‐dimethylphenyl moieties. These phosphole‐containing gold(I) complexes are found to be strongly luminescent in toluene with tunable emission maxima and possess solvatochromic behaviors, suggesting an emission of metal‐perturbed intraligand charge transfer origin. Cyclic voltammetry studies reveal that the presence of gold(I) metal center strongly perturbs the electronic properties of the phosphole moiety of the resultant complexes, which can be further fine‐tuned by the auxiliary ligand on the gold(I) center. In the resistive memory studies, devices based on these alkynylgold(I) complexes exhibit satisfactory binary memory behaviors, demonstrating low threshold voltages in narrow distributions, high durability and low misreading rates. Such performances are believed to be originated from a field‐induced charge transfer of the alkynylgold(I) complexes, in which the electron‐accepting phosphole‐gold(I) unit plays a crucial role in stabilizing the charge transfer state and that led to the observed resistive switching and memory behavior.
A series of benzobphosphole‐based alkynylgold(I) complexes have been synthesized and characterized. These complexes are stable in ambient conditions and display interesting photophysical behaviors tunable by the modification on donor–acceptor properties. Satisfactory resistive memory performances are observed with the representative alkynylgold(I) complexes, displaying potentials to be developed into functional multilevel resistive memories.
A new electron-rich spirothienoquinoline unit, t BuSAF-Th, has been developed via incorporation of a thienyl unit instead of a phenyl unit into the six-membered ring of the spiroacridine (SAF) and ...utilized for the first time as a building block for constructing small-molecule electron donors in organic solar cells (OSCs) and as active layers in organic resistive memory devices. The resulting three-dimensional spirothienoquinoline-containing 1–4 exhibit high-lying highest occupied molecular orbital (HOMO) energy levels. By the introduction of electron-deficient benzochalcogenodiazole linkers, with the chalcogen atoms being varied from O to S and Se, a progressively lower lowest unoccupied molecular orbital (LUMO) energy level has been achieved while keeping the HOMO energy levels similar. This strategy has allowed an enhanced light-harvesting ability without compromising open-circuit voltage (V oc) in vacuum-deposited bulk heterojunction OSCs using 1–4 as donors and C70 as the acceptor. Good photovoltaic performances with power conversion efficiencies (PCEs) of up to 3.86% and high short-circuit current densities (J sc) of up to 10.84 mA cm–2 have been achieved. In addition, organic resistive memory devices fabricated with these donor–acceptor small molecules exhibit binary logic memory behaviors with long retention times and high on/off current ratios. This work indicates that the spirothienoquinoline moiety is a potential building block for constructing multifunctional organic electronic materials.
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![Synthesis of benzo[b]phosph...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/2688-819X/small "Synthesis of benzo[b]phosphole‐based alkynylgold(I) complexes with resistive memory properties modulated by donor–acceptor chromophores")