Bis Zinc Research Articles

Supramolecular Crystals based Fast Single Ion Conductor for Long‐cycling Solid Zinc Batteries

The solid polymer electrolytes (SPEs) used in Zn‐ion batteries (ZIBs) have low ionic conductivity due to the sluggish dynamics of polymer segments. Thus, only short‐range movement of cations is supported, leading to low ionic conductivity and Zn2+ transference (tZn2+). Zn‐based supramolecular crystals (ZMCs) have considerable potential for supporting long‐distance Zn2+ transport; however, their efficiency in ZIBs has not been explored. The present study developed a ZMC consisting of succinonitrile (SN) and zinc bis(trifluoromethylsulfonyl)imide (Zn(TFSI)2), with a structural formula identified as Zn(TFSI)2SN3. The ZMC has ordered three‐dimensional tunnels in the crystalline lattices for ion conduction, providing high ionic conductivities (6.02 × 10−4 S cm−1 at 25 °C and 3.26 × 10−5 S cm−1 at −35 °C) and a high tZn2+ (0.97). We demonstrated that a Zn‖Zn symmetrical battery with ZMCs has long‐term cycling stability (1200 h) and a dendrite‐free Zn plating/stripping process, even at a high plating areal density of 3 mAh cm−2. The as‐fabricated solid‐state Zn battery exhibited excellent performance, including high discharge capacity (1.52 mAh cm−2), long‐term cycling stability (83.6% capacity retention after 70000 cycles (7 months)), wide temperature adaptability (−30 to 50 °C) and fast charging ability.

Supramolecular Crystals based Fast Single Ion Conductor for Long-cycling Solid Zinc Batteries.

The solid polymer electrolytes (SPEs) used in Zn-ion batteries (ZIBs) have low ionic conductivity due to the sluggish dynamics of polymer segments. Thus, only short-range movement of cations is supported, leading to low ionic conductivity and Zn2+ transference (tZn2+). Zn-based supramolecular crystals (ZMCs) have considerable potential for supporting long-distance Zn2+ transport; however, their efficiency in ZIBs has not been explored. The present study developed a ZMC consisting of succinonitrile (SN) and zinc bis(trifluoromethylsulfonyl)imide (Zn(TFSI)2), with a structural formula identified as Zn(TFSI)2SN3. The ZMC has ordered three-dimensional tunnels in the crystalline lattices for ion conduction, providing high ionic conductivities (6.02 × 10-4 S cm-1 at 25 °C and 3.26 × 10-5 S cm-1 at -35 °C) and a high tZn2+ (0.97). We demonstrated that a Zn‖Zn symmetrical battery with ZMCs has long-term cycling stability (1200 h) and a dendrite-free Zn plating/stripping process, even at a high plating areal density of 3 mAh cm-2. The as-fabricated solid-state Zn battery exhibited excellent performance, including high discharge capacity (1.52 mAh cm-2), long-term cycling stability (83.6% capacity retention after 70000 cycles (7 months)), wide temperature adaptability (-30 to 50 °C) and fast charging ability.

Complexes of a Frustrated Lewis Pair-Supported P(-1) Ligand.

Several complexes of the intramolecular frustrated Lewis pair (FLP)-supported P(-1) ligand [iPr2P(C6H4)BCy2{P}]- are presented (Cy=cyclohexyl). Chief among these is the first example of a monomeric zinc bis(phosphido) complex, which was synthesized as a potential precursor for the solution-phase deposition of Zn3P2. While this goal was ultimately unsuccessful, the Zn(II) complex acts as a convenient springboard to other metal phosphide species via transmetallation: affording a tellurium bis(phosphido) complex and a formal adduct of the phosphorus subhalide PPCl2. Trapping experiments show that the PPCl2 adduct can also be prepared directly through the in situ reduction of PCl3 in the presence of an intramolecular FLP ligand. Lastly, we report a formal η2-phosphaborene complex of cobalt(-1) which is isoelectronic to olefin complexes, and explore its bonding via density functional theory (DFT) computations.

Synthesis and characterization of Zinc(II) bis(dithiocarbamate) humidity sensors

Synthesis and characterization of Zinc(II) bis(dithiocarbamate) humidity sensors

Cation valency in water-in-salt electrolytes alters the short- and long-range structure of the electrical double layer

Highly concentrated aqueous electrolytes (termed water-in-salt electrolytes, WiSEs) at solid-liquid interfaces are ubiquitous in myriad applications including biological signaling, electrosynthesis, and energy storage. This interface, known as the electrical double layer (EDL), has a different structure in WiSEs than in dilute electrolytes. Here, we investigate how divalent salts [zinc bis(trifluoromethylsulfonyl)imide, Zn(TFSI)2], as well as mixtures of mono- and divalent salts [lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) mixed with Zn(TFSI)2], affect the short- and long-range structure of the EDL under confinement using a multimodal combination of scattering, spectroscopy, and surface forces measurements. Raman spectroscopy of bulk electrolytes suggests that the cation is closely associated with the anion regardless of valency. Wide-angle X-ray scattering reveals that all bulk electrolytes form ion clusters; however, the clusters are suppressed with increasing concentration of the divalent ion. To probe the EDL under confinement, we use a Surface Forces Apparatus and demonstrate that the thickness of the adsorbed layer of ions at the interface grows with increasing divalent ion concentration. Multiple interfacial layers form following this adlayer; their thicknesses appear dependent on anion size, rather than cation. Importantly, all electrolytes exhibit very long electrostatic decay lengths that are insensitive to valency. It is likely that in the WiSE regime, electrostatic screening is mediated by the formation of ion clusters rather than individual well-solvated ions. This work contributes to understanding the structure and charge-neutralization mechanism in this class of electrolytes and the interfacial behavior of mixed-electrolyte systems encountered in electrochemistry and biology.

Solventless Synthesis of Zinc Sulphide Nanoparticles from Zinc Bis(diethyldithiocarbamate) as a Single Source Precursor.

This study explores the synthesis of nanoparticles through the thermal decomposition of single-source precursors, a method gaining popularity due to its low cost, minimal environmental toxicity, rapidity, scalability, and the ability to form nanoparticles with few defects. Zinc ethyl carbamate was synthesized and characterized using 1HNMR and infrared spectroscopy. Its purity was confirmed through microelemental analysis and melting point determination. The melting point of the complex was determined to be 165 °C. The thermogravimetric analyses indicated a one-step decomposition of zinc ethyl carbamate with a decomposition onset of of 200 °C, yielding a stable ZnS residue. Further thermal decomposition led to the formation of wurtzite phase ZnS nanoparticles, as evidenced by XRD. SEM micrographs displayed mixed spherical, and cubic unevenly sized, polydispersed nanoparticles, while EDX revealed approximately a 1 : 1 Zn to S ratio. Estimated band gap from the Tauc's plot gave 3.93 eV and 3.42 eV for the nanoparticles synthesized at 300 and 400 °C respectively. The wide difference in the band gaps may be as a result of the larger particles observed at 400 °C and the deformations in the sample as observed in the SEM.

Fluorescent probe for Fe3+ detection based on a guest molecular luminescent metal–organic framework

The zinc(II) bis-(8-hydroxyquinoline) (Znq2) has excellent photoluminescence properties, and its fluorescence emission can be significantly quenched by Fe3+ in water. To accelerate the detection response of Znq2 to Fe3+, a luminescent metal–organic framework Znq2@ZIF-8 based on guest molecular luminescence was constructed by growing zeolite imidazolate framework-8 (ZIF-8) on the outer surface of Znq2. The results show that the prepared Znq2@ZIF-8 has an octahedral core–shell structure, a particle size of approximately 1–3 μm, an enhanced specific surface area of 1105.41 m2 g−1, and with a stable green luminescence at 495 nm. A fluorescence analytical method was developed for the detection of Fe3+ in water, the correlation coefficients were significant in the Fe3+ concentration range of 0–600 μmol L−1, and the limit of detection was as low as 3.89 μmol L−1. The spiked recoveries of tap water samples demonstrated that the method could be applied to practical applications. The mechanism of fluorescence detection is that Fe3+ participates in the competitive coordination of Znq2@ZIF-8 metal centers, leading to the collapse of the crystal structure, meanwhile, Fe3+ produces a certain degree of competitive absorption of the excitation light of Znq2@ZIF-8. This method was applied for the detection of Fe3+ in water with good selectivity, anti-interference ability, and has the potential to be used as a rapid detection method.

Zinc-Catalyzed Hydroboration of Carbon Dioxide Amplified by Borane-Tethered Heteroscorpionate Bis(Pyrazolyl)methane Ligands.

The borane-functionalized (BR2) bis(3,5-dimethylpyrazolyl)methane (LH) ligands 1a (BR2: 9-borabicyclo[3.3.1]nonane or 9-BBN), 1b (BR2: BCy2), and 1c (BR2: B(C6F5)2) were synthesized by the allylation-hydroboration of LH. Metalation of 1a,b with ZnCl2 yielded the heteroscorpionate dichloride complexes [(1a,b)ZnCl2] 3a,b. The reaction of 1a with ZnEt2 led to the formation of the zwitterionic complex [Et(1a)ZnEt(THF)] 5. The reaction of complex 3a with two equivalents of KHBEt3 under a carbon dioxide (CO2) atmosphere gave rise to the formation of the dimeric bis(formate) complex [(1a)Zn(OCHO)2]2 8, in which its borane moieties intermolecularly stabilize the formate ligands of opposite metal centers. The allylated precursor Lallyl and its zinc dichloride, diethyl and bis(formate) complexes [(Lallyl)ZnCl2] 2, [(Lallyl)ZnEt2] 4, and [(Lallyl)Zn(OCHO)2] 7 were also isolated. The catalyst systems composed of 1 mol % of 3a or 3b and two equivalents of KHBEt3 hydroborated CO2 at 1 bar with pinacolborane (HBPin) to the methanol-level product H3COBPin (and PinBOBPin) in yields of 42 or 86%, respectively. The catalyst systems using the unfunctionalized complex [(LH)ZnCl2] 6 and KHBEt3 or KHBEt3/nOctBR2 (BR2: 9-BBN or BCy2) hydroborated CO2 to H3COBPin but in 2.5- to 6-fold lower activities than those exhibited by 3a,b/KHBEt3. The hydroboration of CO2 using 8 as a catalyst led to yields of 39-43%, comparable to those obtained with 3a/KHBEt3. The results confirmed that the catalytic intermediates benefit from the incorporated boranes' intra- or intermolecular stabilizations.

Volatile N,N′-dialkyl-β-dialdiminate complexes of magnesium and zinc as possible chemical vapor deposition precursors

A series of volatile magnesium(II) and zinc(II) bis(β-dialdiminato) complexes (of stoichiometry M[RN(CH)3NR]2 where R = methyl, ethyl, isopropyl, or tert-butyl) have been prepared and investigated as potential precursors for the chemical vapor deposition of thin films. Several of the compounds have been characterized crystallographically; the metal centers adopt pseudo-tetrahedral geometries with the two ligands forming six-membered rings with the metal center. All eight compounds sublime cleanly both in vacuum and under 1 atm of N2, and the most volatile compounds (those having N-methyl substituents) have vapor pressures of 1 Torr at 88 (Mg) and 90 °C (Zn). In general, metal complexes of N,N′-dialkyl-β-dialdiminate ligands are more volatile than their corresponding N,N′-dialkyl-β-diketiminate and N,N-dialkylamidinate analogues.

Syntheses of high molecular mass polyglycolides via ring‐opening polymerization with simultaneous polycondensation (ROPPOC) by means of tin and zinc catalysts

AbstractGlycolide was polymerized in bulk by means of four different ROPPOC catalysts: tin(II) 2‐ethylhexanoate (SnOct2), dibutyltin bis(pentafluoro‐phenoxide) (BuSnOPF), zinc biscaproate (ZnCap), and zinc bis(pentafluoro‐phenyl sulfide) (ZnSPF). The temperature was varied between 110 and 180°C and the time between 3 h and 7 days. For the few polyglycolides (PGAs) that were soluble extremely high molecular masses were obtained. The MALDI TOF mass spectra had all a low signal‐to‐noise ration and displayed the peaks of cyclic PGAs with a “saw‐tooth pattern” indicating formation of extended‐ring crystallites in the mass range below m/z 2500. The shape of DSC curves varied considerably with catalyst and reaction conditions, whereas the long‐distance values measured by SAXS were small and varied little with the polymerization conditions.

L-Lysine-Functionalized Nickel–Zinc Bis(Dithiolene) Metal–Organic Framework for Electrochemical Chiral Recognition of Tryptophan Enantiomers

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Enabling 4.5 V Solid Polymer Batteries through a 10 µm, Crosslinked Polyether Electrolyte

AbstractThe implementation of solid polymer electrolytes (SPEs) in energy‐dense batteries faces severe challenges including sluggish ionic diffusion, oxidation tendency at the cathode interface, dendrite protrusion from the metallic anode, as well as the technological incompatibility with the layer stack‐up cell assembly. Herein, an in‐situ polymerization strategy is presented to deal with above dilemma for the solid battery prototyping. The in situ cross‐linked poly(ethylene glycol) diglycidyl ether is embedded within the nanocellulose framework, endowing SPE membrane with the reinforced mechanical strength (11.31 MPa) at the thickness of 10 µm as well as superior ionic conductance (150 mS). After a rigorous selection, the sacrificial triphenylphosphine additive preferentially oxidizes on the LiNi0.8Mn0.1Co0.1O2 (NCM811) cathode to form the cathode electrolyte interface during the formation charging. Concurrently, the solvated zinc(II) bis(trifluoromethylsulfonyl)imide constructs the polyether/LiZn mosaic layer on the Li foil, which effectively promotes interfacial cation diffusion and horizontal deposits propagation. By pairing the polymerized SPE with the thin‐layer Li foil (50 µm) and the NCM811 cathode (25 mg cm−2), the 94 mAh pouch‐format cell can realize a gravimetric/volumetric energy density of 397.5 Wh kg−1 and 1197.6 Wh L−1, high‐voltage tolerance till 4.5 V, and robust cyclability (95.1% capacity retention for 200 cycles).

Novel electrolyte assisted ultralow-temperature zinc battery

Secondary battery is an indispensable component in energy storage as it can uninterruptedly store the energy and release it when being required. Among them, zinc (Zn) rechargeable battery gains much attention due to its cost advantage. However, poor climate adaptation much weaken the competitiveness, and temperature-induced deterioration can be mainly blamed on the slow reaction-kinetics of Zn anode under low temperature. Under this scenario, an anti-freezing electrolyte with Zinc (II)Bis(trifluoromethanesulfonyl)imide (Zn(TFSI)2) salt and ternary solvents of acetonitrile (AN), methyl acetate (MA) and dichloromethane (DCM) is proposed. It successfully broadens the working temperature of Zn secondary battery to − 90 °C. The elaborately regulated solvation can ensure smooth ion-transfer in liquid zone, more importantly, it expedites the desolvation without much affecting the interface transportation. With the optimized electrolyte configuration, reversible Zn plating/stripping at ultra-low temperature has been realized. The Zn|polytriphenylamine (PTPAn) battery thus can reserve 70 % capacity at − 80 °C, and present extremely stable cycling and impressive rate capability at − 80 °C and − 60 °C. The results well address the kinetics issues encountered in the low-temperature Zn secondary battery, and reveals that only with appropriate solvation, the high ion-permeability of the interface as well as easy de-solvation can be guaranteed. The work provides a guideline for designing advanced electrolyte, and supplies a reliable and effective strategy for the all-weather electrochemical energy storage.

Hydrosilylation of nitriles and tertiary amides using a zinc precursor.

We report a competent and selective hydrosilylation of nitriles and tertiary amides catalyzed by the readily available zinc bis(hexamethyldisilazide) under solvent-free and mild conditions, making it a sustainable and desirable alternative to existing methods. Both protocols afforded high conversion, superior selectivity, and a broad substrate scope, from electron-withdrawing to electron-donating and heterocyclic substitutions.

Tunable zinc benzamidinate complexes: coordination modes and catalytic activity in the ring-opening polymerization of L-lactide.

Seven asymmetric zinc benzamidinate complexes featuring or lacking side-arm functionalities were synthesized. Using equimolar zinc reagent produced distinct dinuclear motifs [(C6H5-C = NC6H5)ZnEt]2 (R = tBu, 1; (CH2)2OMe, 2; (CH2)2NMe2, 3). Half the zinc reagent yielded dinuclear [(C6H5-C = NC6H5)2Zn]2 (R = tBu, 4) or mononuclear zinc bis(chelate) complexes (R = (CH2)2OMe, 5; (CH2)2NMe2, 6; CH2Py, 7). Molecular structures of 1-4 and 7 were determined via single-crystal X-ray diffraction. Altering benzamidinate substituents modifies both coordination modes and catalytic activities in ring-opening polymerization of L-lactide. Specifically, complex 7 exhibits enhanced catalytic activity at 25 °C using 100 equivalents of L-lactide with a turnover frequency of 1820 h-1.

SYNTHESIS OF 1,1′-(2,3,5,6-TETRAFLUORO-1,4-PHENYLENE)DIPROPAN-1-ONE

1-(Pentafluorophenyl)propan-1-one reacts with zinc in the presence of catalytic amounts of SnCl2 under heating in dimethyl formamide to give (2,3,5,6-tetrafluoro-4-propionylphenyl)zinc chloride and bis(2,3,5,6-tetrafluoro-4-propionylphenyl)zinc. 1,1¢-(2,3,5,6-Tetrafluoro-1,4-phenylene)dipropan-1-one was synthesized from these organozinc compounds and propionyl chloride in the presence of CuI. The reaction of organozinc compounds obtained from 3-bromo-1,2,4,5-tetrafluorobenzene leads to the formation of 1-(2,3,5,6-tetrafluorophenyl)propan-1-one

Understanding the Surprising Ionic Conductivity Maximum in Zn(TFSI)2 Water/Acetonitrile Mixture Electrolytes.

Aqueous electrolytes composed of 0.1 M zinc bis(trifluoromethylsulfonyl)imide (Zn(TFSI)2) and acetonitrile (ACN) were studied using combined experimental and simulation techniques. The electrolyte was found to be electrochemically stable when the ACN V% is higher than 74.4. In addition, it was found that the ionic conductivity of the mixed solvent electrolytes changes as a function of ACN composition, and a maximum was observed at 91.7 V% of ACN although the salt concentration is the same. This behavior was qualitatively reproduced by molecular dynamics (MD) simulations. Detailed analyses based on experiments and MD simulations show that at high ACN composition the water network existing in the high water composition solutions breaks. As a result, the screening effect of the solvent weakens and the correlation among ions increases, which causes a decrease in ionic conductivity at high ACN V%. This study provides a fundamental understanding of this complex mixed solvent electrolyte system.

Effect of Zn(TFSI)2 on the performance-aging time of perovskite solar cells

Hole transport layers (HTLs) are one of the essential layers of perovskite solar cells (PSCs). Generally, 2,2ʹ,7,7ʹ-Tetrakis [N,N-di(4-methoxyphenyl)amino]-9,9ʹ-spirobifluorene (spiro-MeOTAD) doped by lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) is used as the HTL in PSCs. PSCs employing spiro-MeOTAD require an additional aging process to reach an optimized point of photovoltaic performance due to doping and energy alignment. However, LiTFSI is responsible for low thermal stability and has a hygroscopic nature; therefore, Zinc(II) bis(trifluoromethanesulfonyl)imide (Zn(TFSI)2) has been reported as an outstanding candidate to replace LiTFSI. Nevertheless, utilization of Zn(TFSI)2 as a dopant for PSCs has rarely been reported, which is likely due to the difficulty in achieving high device performances comparable to that with LiTFSI. Herein, we investigate the effect of Zn(TFSI)2 on the doping kinetics of spiro-MeOTAD and correlate it with the time-dependent photovoltaic performance of PSCs employing Zn(TFSI)2. Devices with Zn(TFSI)2 require a considerably longer aging time (∼270 h) to reach the optimized performance, while LiTFSI takes only ∼20 h due to the different doping kinetics of spiro-MeOTAD depending on the dopant. Remarkably, engineering at the interface of the perovskite/HTL can effectively shorten the device aging time by manipulating the recombination rate, leading to a comparable aging time to LiTFSI.

Zn-catalyzed coordination-insertion depolymerization strategy of poly(3-hydroxybutyrate) under bulk conditions

Poly(3-hydroxybutyrate) (PHB), as a bio-based polyester material, is considered to be one of the most promising alternatives to conventional plastics. With the mass production and spread in application of PHB, the recycling of end-of-life PHB will be crucial. Compared to slow biodegradation, chemical recycling can rapidly provide monomers and profitable platform chemicals and maintain the value and usefulness of PHB materials. In this work, the Zn-catalyzed coordination-insertion depolymerization of PHB to alkyl 3-hydroxybutanoate via an alcoholysis strategy was explored in detail. Zinc bis[bis(trimethylsilyl)amide] (Zn(HMDS)2), as an environmentally friendly and versatile transesterification catalyst, could facilitate depolymerization of PHB smoothly under mild and solvent-free conditions, providing the degradation product alkyl 3-hydroxybutanoate with high yield and purity. Additionally, the influence of reaction conditions such as temperature, molar equivalents of alcoholysis reagents, and polymer tacticity on the depolymerization process was explored and optimized. In this way, the depolymerization of PHB through a coordination-insertion depolymerization mechanism was achieved for the first time. This work enriches the options for the chemical upcycling of PHB plastics.

Reviewed, accepted, and published version of work Comment on "Comment on "Crystallographic and theoretical study of the atypical distorted octahedral geometry of the metal chromophore of zinc(II) bis((1R,2R)-1,2-diaminocyclohexane) dinitrate""

Reviewed, accepted, and published version of work Comment on "Comment on "Crystallographic and theoretical study of the atypical distorted octahedral geometry of the metal chromophore of zinc(II) bis((1R,2R)-1,2-diaminocyclohexane) dinitrate""