Cluster-based Coordination Polymers Research Articles

Suppressing the Thermal Quenching Effect via a Cluster Conformer in Copper(I)-Iodide Coordination Polymeric Phosphors for High-Power White LED Lighting.

High-power LED lighting is a crucial challenge due to the notorious thermal quenching (TQ) effect of traditional phosphors at high operating currents, which would result in poor device performance and hamper practical optoelectronic application. Herein, we demonstrate ligand engineering of a cubane- versus staircase-like [Cu4I4] conformer as a node in coordination polymers, which remarkably suppresses the TQ effect of cluster-based photoluminescence. For complex 1 (the formula [Cu4I4(bbimb)2]n) with the cubane-like [Cu4I4] conformer as a node, the metallophilicity interaction enables ultrabright triplet emission with a photoluminescence quantum yield over 82%, and the phonon-assisted detrapping process of excitons effectively suppresses the TQ effect in the wide temperature range. In contrast, the staircase-like [Cu4I4] conformer as a node in complex 2 (the formula [Cu4I4(bbtmb)2]n) exhibits a serious TQ effect over the investigated temperature. Phosphor-converted white LEDs (pc-wLEDs) were fabricated by integrating the cluster-based coordination polymers as a color converter, and their electroluminescence performances were investigated under high bias currents. The prototype pc-wLED device by incorporating the phosphor with the suppressed TQ effect exhibits a continuous rise in brightness under a high bias current of 300 mA. The results demonstrate that ligand engineering of the cluster conformer via suppressing the TQ effect proves efficient in designing an ideal color converter for high-power pc-wLED lighting.

Fabrication of multinuclear copper cluster-based coordination polymers as urease inhibitors.

This study focused on the design and synthesis of two Cu-based coordination polymers, [Cu2(4-dpye)(5-HSIP)(μ3-O)(H2O)2]·3H2O (Cu-CP-1) and [Cu(4-dpye)0.5(BCA)2] (Cu-CP-2), where 4-dpye = N,N'-bis(4-pyridinecarboxamide)-1,2-ethane, 5-H3SIP = 5-sulfoisophthalic acid, and HBCA = benzoic acid, by using a hydrothermal method. Single-crystal X-ray diffraction (SCXRD) study revealed that by adding various auxiliary ligands, the architectures of the Cu-CPs could be altered, yielding two distinct multinuclear Cu clusters. Moreover, the Cu-CPs can be used as urease inhibitors (UIs). In vitro experiments showed that the Cu-CPs had good urease inhibition effects with IC50 values of 0.53 ± 0.01 μM for Cu-CP-1 and 1.44 ± 0.01 μM for Cu-CP-2 and 98.48% (Cu-CP-1) and 96.27% (Cu-CP-2) inhibition of urease was achieved at a concentration of 100 μM, respectively. Furthermore, the inhibition effect of the tetranuclear Cu-CP was better than that of the binuclear Cu-CP. To better understand the potential mechanism of inhibition of the two copper complexes, we performed kinetic analysis using Lineweaver-Burk (L-B) plots in the presence of different concentrations of urea and different concentrations of inhibitors, and both Cu-CP-1 and Cu-CP-2 showed a non-competitive mode of inhibition. In addition, molecular docking analysis showed that the Cu-CPs were able to enter well into the urease binding pocket, thus interacting with key amino acid residues of urease to different degrees. Both kinetic and molecular docking studies theoretically explain and demonstrate the inhibition effect of both Cu-CPs on urease activity in vitro, which is expected to provide reasonable guidance and effective strategies for the development of novel, efficient, stable and safe CP-based UIs.

Inorganic-organic hybrid Cu-dipyridyl semiconducting polymers based on the redox-active cluster [SFe3(CO)9]2-: filling the gap in iron carbonyl chalcogenide polymers.

The construction of sulfur-incorporated cluster-based coordination polymers was limited and underexplored due to the lack of efficient synthetic routes. Herein, we report facile mechanochemical ways toward a new series of SFe3(CO)9-based dipyridyl-Cu polymers by three-component reactions of [Et4N]2[SFe3(CO)9] ([Et4N]2[1]) and [Cu(MeCN)4][BF4] with conjugated or conjugation-interrupted dipyridyl ligands, 1,2-bis(4-pyridyl)ethylene (bpee), 1,2-bis(4-pyridyl)ethane (bpea), 4,4'-dipyridyl (dpy), or 1,3-bis(4-pyridyl)propane (bpp), respectively. X-ray analysis showed that bpee-containing 2D polymers demonstrated unique SFe3(CO)9 cluster-armed and cluster-one-armed coordination modes via the hypervalent μ5-S atom. These S-Fe-Cu polymers could undergo flexible structural transformations with the change of cluster bonding modes by grinding with stoichiometric amounts of dipyridyls or 1/[Cu(MeCN)4]+. They exhibited semiconducting behaviors with low energy gaps of 1.55-1.79 eV and good electrical conductivities of 3.26 × 10-8-1.48 × 10-6 S cm-1, tuned by the SFe3(CO)9 cluster bonding modes accompanied by secondary interactions in the solid state. The electron transport efficiency of these polymers was further elucidated by solid-state packing, X-ray photoelectron spectroscopy (XPS), X-ray absorption near-edge spectroscopy (XANES), density of states (DOS), and crystal orbital Hamilton population (COHP) analysis. Finally, the solid-state electrochemistry of these polymers demonstrated redox-active behaviors with cathodically-shifted patterns compared to that of [Et4N]2[1], showing that their efficient electron communication was effectively enhanced by introducing 1 and dipyridyls as hybrid ligands into Cu+-containing networks.

One-Dimensional Cu(I) coordination polymers with multi-stimuli-responsive luminescence

Luminescent coordination polymers (CPs) with one-dimensional (1D) closely-packed structures usually display poor performances in stimuli-responsive luminescence due to the low porosity and high rigidity. Here, we reported a multi-stimuli-responsive 1D luminescent [Cu2I2]-cluster-based CP (CuIP-OPY) with piezochromic, thermochromic and oxygen sensing properties. Attributing to the flexibility of the OPY ligand, which twists under external forces and heating, respectively, CuIP-OPY shows obvious piezochromic and thermochromic luminescence. Moreover, although its porosity is only 1.1%, oxygen can still quench its luminescence intensity by 57.53%. To further confirm the related mechanism, we also synthesized a [Cu2Cl2]-cluster-based CP with similar structure, namely CuClP-OPY, that displays higher rigidity, and compared the differences between these two CuXP-OPY (X = I, Cl) in the multi-stimuli-responsive behavior.

High-temperature negative thermal quenching phosphors from molecular-based materials.

High-temperature negative thermal quenching (NTQ) phosphors are crucial to high-performance light-emitting devices. Herein, we report the high-temperature NTQ effect in deep-red to near-infrared (NIR) emitting copper iodide cluster-based coordination polymers as unconventional phosphors, whose NTQ operating temperature can reach as high as 500 K, the highest temperature reached by NTQ molecular-based materials.

A One-Dimensional Cu(I) Coordination Polymer with Optical Sensing of Oxygen and Temperature

Due to their tight structures, it is usually difficult for one-dimensional (1D) coordination polymers (CPs) to form permanent pores unless 2D and 3D topologies are formed via supramolecular interactions, so studies in the field of oxygen sensing on 1D CPs are rarely reported. Here, we report a 1D Cu(I) cluster-based CP with dual sensing characteristics for temperature and oxygen. Even if the porosity is only 6.6%, the quenching rate of this CP reaches 98.4% with 1 bar O2 at room temperature. Its luminescence intensity exhibits a unique thermal “quenching, then activating” behavior during monotonic variations in temperature.

A Copper Iodide Cluster-Based Coordination Polymer as an Unconventional Zero-Thermal-Quenching Phosphor.

Phosphor-converted white light-emitting diodes (pc-wLEDs) are promising candidates for next-generation solid-state lighting and display technologies. However, most of the conventional phosphors in pc-wLED devices suffer from serious thermal quenching (TQ) at high temperatures. Herein, we investigate an unconventional high-efficiency metal-halide cluster-based phosphor with dynamic Cu-Cu interactions that can resist the TQ effect of photoluminescence. The temperature-dependent structure and solid-state and in situ NMR spectroscopy reveal that the weakening of the Cu-Cu interaction in such a phosphor system enables the electronic structural transition from a bonding to a nonbonding state and hence sustains the PL efficiency at high temperatures (up to 100 °C). The pc-wLEDs incorporating the zero-TQ phosphor show a rapid brightness rise even at a high bias current (1000 mA) with a color rendering index as high as 90, comparable to the commercial phosphor-based prototype LEDs (e.g., YAG:Ce3+). This work establishes a novel prototype of a cluster-based phosphor featuring dynamic intermetallic interactions, which paves the way for the exploration of pc-wLEDs against thermal quenching.

Lung Cancer Cell Apoptosis Induced by Two New Trinuclear Cluster-Based Coordination Polymers

Lung Cancer Cell Apoptosis Induced by Two New Trinuclear Cluster-Based Coordination Polymers

A Heniconuclear {Mn21} Cluster-Based Coordination Polymer with Manganese(II) Linkers Showing High Proton Conductivity.

An unprecedented metal-linked cluster-based coordination polymer, composed of heniconuclear {Mn21} clusters and Mn(II) ions as the nodes and linkers, respectively, was self-assembled from a facile aqueous synthesis. The structural analysis reveals that the compound possesses a rare 3D 8-connected hex framework topology. Significantly, the compound demonstrates a high proton conductivity of 1.06 mS cm-1 at 373 K and 98% RH and exhibits a magnetocaloric effect with a magnetic entropy change of -9.94 J kg-1 K-1 at H = 80 kOe and T = 6.0 K.

A dinuclear cuprous chloride coordination polymer with grinding triggered luminescence enhancement and temperature dependent luminescent properties

A cuprous cluster-based luminescent coordination polymer [Cu(OPY)Cl]n (1, OPY ​= ​4,4′-(oxybis (4,1-phenylene))dipyridine) has been hydrothermally synthesized and structurally characterized. Compound 1 consists of bent butterfly dinuclear [Cu2Cl2] core and V-shaped OPY ligand, which exhibits a perpendicularly interpenetrated 2D ​+ ​2D → 3D structural characteristic. Compound 1 emits orange red luminescence originated from the dual-emitting behavior at room temperature in the solid state. Its photoluminescence properties have been fully studied and verified by time-dependent density functional theory (TD-DFT) calculations. In addition, the grinding and temperature dependent luminescence properties of 1 have also been investigated in detail.

Bottom-up synthesis strategy of a two-dimensional {Fe5} cluster-based coordination polymer: stepwise formation of a {Fe5} cluster and its dimension augmentation

A 2D cluster-based coordination polymer of {Fe5}-2D was developed by hierarchical dimension augmentation from its 1D coordination polymer of {Fe5}-1D and discrete 0D cluster of {Fe5}-0D. And a possible bottom-up synthesis mechanism was proposed.

2D→3D Polycatenated Cu(I) Coordination Polymer: Photocatalytic Property and Protective Activity on COPD by Reducing the INF-γ Production.

Reported here is a new [Cu4I4] cluster-based coordination polymer, namely [Cu4I4(bib)2]n·n(DMF) (1, bib = 1,4-bis(imidazolyl)butane, DMF = N,N'-dimethylformamide), which was synthesized by the self-assemble reaction of CuI, bib and KI under solvothermal conditions. Remarkably, compound 1 shows promising photocatalytic performance toward to the degradation of MB solution under visible light irradiation. For the COPD treatment, the ELISA detection kit was conducted to determine the content of INF-γ released by the respiratory tract mucosal epithelial cells. In addition to this, the activation levels of the NF-κB signaling pathway were still need to be assessed by the real time RT-PCR after the compound treatment.

Heterobimetallic Cluster-Based Coordination Polymers: Assembly, Structures and Third-Order Nonlinear Optical Properties.

Reactions of (NH4 )2 WS4 with CuCN, CuCN/1,2-bis(4-pyridyl)propane (bppa) or [Cu(MeCN)4 ]PF6 /bppa under different reaction conditions afforded a set of two- or three-dimensional W/Cu/S cluster-based coordination polymers including {[Et4 N]2 [WS4 Cu4 (μ-CN)2 (μ-I)2 ]}n (1), [WS4 Cu4 (μ-CN)2 (bppa)2 ]n (2) and {[WS4 Cu4 (bppa)4 ](PF6 )2 }n (3), respectively. Compound 2 can be readily formed from reaction of 1 with bppa under solvothermal conditions. Compounds 1 and 2 feature two-dimensional networks with a "sql" topology, while 3 possesses a two-fold interpenetrated three-dimensional net with a rare "reo" topology. Compounds 1-3 in DMF exhibited different third-order nonlinear optical responses, and they all showed a reverse saturable absorption while 2 held a strong self-focusing effect.

An unusual Pb8 clusters based coordination polymer with room-temperature orange phosphorescence

A new 2D phosphorescence lead metal cluster-based coordination polymer (CP) [Pb4(μ2-OH) (μ3-OH) (μ4-O) (3-qlc)4]n (1; 3-qlc ​= ​3-quinolinecarboxylate) has been successfully synthesized by solvothermal reaction. CP 1 is a robust Pb(II) CP constructed by a rare [Pb8(μ2-OH)2 (μ3-OH)2 (μ4-O)2(COO)8] cluster units and 3-qlc ligands. The bulky clusters provide architectural stability to the framework of 1. Interestingly, CP 1 exhibited almost pure room-temperature orange phosphorescence with absolute phosphorescence quantum yields of 3.3% and a phosphorescence lifetime of 1.52 ​ms benefiting from the restriction of molecular vibrations/rotations of organic luminogens (3-qlc) and the heavy-atom effect of Pb(II).

Synthesis, structure, magnetocaloric effect and DFT calculations of a MnII cluster-based inorganic coordination polymer

A new Mn inorganic coordination polymer, formulated as {(H3O)2[Mn3(SO4)3(μ3-OH)2(H2O)2]}n (1), was synthesized by a hydrothermal reaction and characterized magnetically. Structural analysis reveals that 1 features a MnII3-hydroxyl-sulfate layer which is extended into a 3D supramolecular framework through hydrogen bonds with interlayer hydronium ions. Magnetic measurements indicate that 1 exhibits homospin ferrimagnetic behavior with a (5/2, 10/2) spin topology and a 1/3 magnetization plateau. The spontaneous magnetization induced by ferrimagnetic behavior was observed. Single-crystal magnetic measurements indicate that the a-axis of 1 is the magnetic easy axis. Notably, 1 exhibits significant MCE with the maxiumu −ΔSm value of 14.58 J Kg−1 K−1 for ΔH = 8 T at 16 K. Moreover, the density functional theory (DFT) calculations were performed to explain the ferrimagnetic behavior.

RETRACTED ARTICLE: 3D Cu(II) Cluster-Based Coordination Polymer: Increasing the Activity of Prothrombin and Preventing Postpartum Hemorrhage

In the current study, via applying a hybrid-ligand method, a novel Cu(II)-based coordination polymer, formulated as [Cu2(OH)(bib)(bpt)]·H2O (1) (H3bpt = biphenyl-3,4′,5-tricarboxylic acid, bib = 1,4-bis(1-imidazolyl)benzene), has been successfully obtained by a isothermal method. Its treatment effect against postpartum hemorrhage was assessed in the bio-study. Firstly, through the model establishment and compound treatment, the prothrombin activity in the plasma was assessed by measuring the prothrombin time. Next, the levels of the factor XI and IX were also assessed by ELISA (enzyme linked immunosorbent assay detection kit). In addition to this, the prevention activity of the compound on the disseminated intravascular coagulation (DIC) during postpartum hemorrhage was also evaluated by measuring the inflammatory response of the inflammatory cytokines, such as IL-1β (interleukin-1β) and TNF-α (tumor necrosis factor-α). The inflammatory signaling relative expression was assessed via the real time RT-PCR (reverse transcription-polymerase chain reaction) as well. Above all, we can see that the compound has excellent treatment activity on DIC disease by inhibiting p53 and nf-κb relative expression in the endothelial cells.

Cluster-Based Coordination Polymers of Mn/Fe-Oxo Pivalates and Isobutyrates

Polynuclear coordination clusters can be readily arranged in cluster-based coordination polymers (CCPs) by appropriate bridging linkers. This review provides an overview of our recent developments in exploring structurally well-defined Mn/Fe-oxo pivalate and isobutyrate building blocks in the formation of CCPs assemblies with an emphasis on synthetic strategies and magnetic properties.

Highly Stable Three-Dimensional Silver (I) Chloride Cluster Based Coordination Polymer and Its Dye Removal Properties

A highly stable three-dimensional (3D) silver chloride cluster based coordination polymer (CP) with diphosphines ligand with the formula of [Ag4Cl4(L)2]n (1) (L = 1,3-bis(diphenylphosphino)propane, bdpp) has been prepared at room temperature. 1 was examined for the removal of Rhodamine B in aqueous solution, exhibiting potential for the removal of contaminants from wastewater.

Penta-nuclear [Ag5I6] Cluster-Based Photochromic Hybrid: Synthesis, Structure, Dye Sorption, and Separation

An [Ag5I6] cluster-based coordination polymer has been successfully constructed with the assistance of a polydentate organic amine hexamethylenetetramine (Hmta) as the linker, [NH4][Ag5I6(Hmta)] (1). Compound 1 features an anionic 2D bilayer network wherein the combination of Ag(I) with I– and N atom gives rise to a novel [Ag5I6] secondary building unit and further generates the final architecture with free NH4+ being located in the space of the framework. Interestingly, compound 1 exhibits a cation exchange behavior which can efficiently capture and separate methylene blue (MB) in a binary mixture of dye solution. Desorption experiments have been performed, showing that the MB molecules in dye-loaded samples can be readily discharged when triggered by Na+. Moreover, reversible photochromism is observed for solid 1, displaying a rapid color response to light illumination.

Novel silver(i) cluster-based coordination polymers as efficient luminescent thermometers

Two original Ag-based clusters with a multidentate N-containing organic linker have been constructed featuring temperature-dependent luminescence behavior.