Guanidinium Lactate Ionic Liquid: An Efficient and Recycling Catalyst for Michael Addition Reaction

A facile and efficient 1, 4-conjungate addition（Michael addition） reaction of active methylene compounds to aft-unsaturated compounds, catalyzed by guanidinium lactate ionic liquid（IL9）, has been developed. A range of chalcones and nitroalkenes together with active methylene compounds have been converted smoothly to the corresponding products in high yields.

Surface Treatment of Inorganic CsPbI_(3) Nanocrystals with Guanidinium Iodide for Efficient Perovskite Light-Emitting Diodes with High Brightness

The remarkable evolution of metal halide perovskites in the past decade makes them promise for next-generation optoelectronic material.In particular,nanocrystals(NCs)of inorganic perovskites have demonstrated excellent performance for light-emitting and display applications.However,the presence of surface defects on the NCs negatively impacts their performance in devices.Herein,we report a compatible facial post-treatment of CsPbI_(3) nanocrystals using guanidinium iodide(GuI).It is found that the GuI treatment effectively passivated the halide vacancy defects on the surface of the NCs while offering effective surface protection and exciton confinement thanks to the beneficial contribution of iodide and guanidinium cation.As a consequence,the film of treated CsPbI_(3) nanocrystals exhibited significantly enhanced luminescence and charge transport properties,leading to high-performance light-emitting diode with maximum external quantum efficiency of 13.8%with high brightness(peak luminance of 7039 cd m^(−2) and a peak current density of 10.8 cd A^(−1)).The EQE is over threefold higher than performance of untreated device(EQE:3.8%).The operational half-lifetime of the treated devices also was significantly improved with T50 of 20 min(at current density of 25 mA cm^(−2)),outperforming the untreated devices(T50~6 min).

Novel guanidinium-based ionic liquids as stationary phases for capillary gas chromatography

The present study describes guanidinium-based ionic liquids（GBILs） as stationary phases for capillary gas chromatography （CGC） and to the best of our knowledge,no related reports are available up to now.In this study,a hexaalkylguanidinium ionic liquid（DOTMG-NTf;） was synthesized and coated statically onto capillary columns.Selectivity of the stationary phase was evaluated by separating Grob test mixture,test mixture,alcohols mixture,and fatty acid methyl esters mixture,and thermal stability was investigated as well.The present study demonstrates that GBILs as CGC stationary phases exhibit satisfactory selectivity and thermal stability and have a great potential as new candidates for CGC stationary phases.

Ionic Liquid Solvent Based on Cyclic Guanidinium Cation for Nucleophilic Displacement Reactions

The nucleophilic displacement reaction of n-bromooctane and potassium iodide in ionic liquid based on cyclic guanidinium cation(2) was investigated. The kinetic reasult shows that the rate of the reaction is enhanced in ionic liquid (2). The same reaction in [bmim][PF6](1)(where bmim=1-butyl-3-methylimidazolium) was also studied. It was found that as a reaction medium ionic liquid (2) is better than (1) for nucelophilic displacement reactions.

Selectivity of guanidinium ionic liquid for capillary gas chromatography

A guanidinium ionic liquid,N,N,N＇,N＇-tetrahexyl-N＂,N＂-dimethylguanidinium bis（trifluoromethane）sulfonylimide（THDMGNTf2）, was synthesized and used as stationary phase for capillary gas chromatography.In comparison with imidazolium ionic liquid stationary phase,the present new stationary phase exhibits quite different selectivity and behaves more like a low polar stationary phase.The guanidinium ionic liquid of THDMG-NTf2 exhibited better separation of Grab test mixture than imidazolium ionic liquid of 1-octyl-3-butylimidazolium bis（trifluoromethane）sulfonylimide（OBIM-NTf2）.Solvation parameter model was also used to evaluate the selectivity of THDMG-NTf2.Additionally,essential oil of Magnolia biondii Pamp was analyzed to further evaluate the selectivity of THDMG-NTf2 for a sample of complicated components.Satisfactory separation of the essential oil was achieved on a THDMG-NTf2 column（10 m） while using a commercial column（30 m） as reference.The present study shows that the guanidinium ionic liquid possesses novel chromatographic selectivity and has great potential for wide applications.

Novel Brфnsted Acidic Ionic Liquid Based on a Cyclic Guanidinium Cation:a Green,Efficient,and Recyclable Dual Slovent-catalyst System for Fisher Esterification

A novel BrФnsted acidic ionic liquid（IL） based on the cyclic guanidinium cation has been synthesized. This IL, as a strong BrФnsted acid catalyst or solvent, shows high catalytic activity and biphsaic behavor in the esterifications of carboxylic acids and alcohols. The produced esters as a separate phase can be conveniently decanted out from the IL and the IL is recyclable without any loss of catalytic activity.

Lewis Acidic Guanidinium Ionic Liquids: Novel, Efficient and Recyclable Catalysts for Aminolysis of Epoxides

Lewis acidic guanidinium ionic liquid（LAGIL） 2c was used as a novel, efficient and recyclable catalyst for aminolysis of epoxides under solvent-free and room temperature conditions, giving the corresponding β-amino alcohols with moderate to excellent regioselectivity（up to 91：9） in high yields（up to 97%）. In addition, LAGIL 2c was recycled three times without any loss of catalytic activity and selectivity to the product.

Crystal and Molecular Structure of Guanidinium Pentamolybdobis (n-amylphosphonate)(CN3H6)4[(n-C5H11P)2Mo5O21]

The crystal structure of guanidinlum pentamolybdobis(n-ainylphcsphonate), which contains the longest carbon chain hitherto known, was determined by single-crystal X-ray diffraction analysis. It belongs to monoclinic, space group C2/c, Z = 4, 0=18.857(2), b=12.170(1), c=18. 294(2) A .β=102.73 (2), V=4095. 2A3.u= 140. 34 cm-1. The intensity data were collected on an Enraf-Nonius CAD4 diffractometer with MoKa radiation. The positions of all molybdenum and phosphorus atoms were determined by the direct method. The other non-hydrogen atoms were revealed by difference Fourier synthesis. The structure was refined by full-matrix least-squares procedure to a final R value of 0. 068. The structure of the anion is similar to [(CH2P)2Mo5O21]4-, [(NH3C2H4P)2Mo6O21]2-, [(n-C3H7As)2Mo5O21]--, and [(C3H5As)2Mo6O21]4-. It consists of a ring of five distorted MoO, octahedra joined by edge-sharing, except for one pair which is joined by corner- sharing. The size of the Mo6O16 ring is close to those of [(CH3P)2Mo5O21]4- and [(NH2C2H4P)2Mo5O21]2- and much smaller than those of [(n-C2H7As)2Mo5O21]4-and [(C2H6As)2Mo6O21]4-. The symmetry of the anion, however, to the same at those of its arsenic con-seners [(n- C2H7As )2Mo5O21 ]4- and [( C3H5- As )2Mo5O21]4-, but different from those of [(CH3P)2Mo5O21]4-and [(NH3C2H4P)2Mo5O21]2-. The average bond angles O-P-O were estimated on the basis of assuiming that anion [(RP)2Mo5O244-could be formed.

Guanidinium Iodides-based Ionic Liquids: Synthesis and Application for Dye-sensitized Solar Cells(DSSCs)

A series of guanidinium ionic liquids（GILs） was designed, synthesized, and used as electrolytes for dye-sensitized solar cells（DSSCs）. The effect of electrolytes containing GILs on the photovoltaic performance of DSSCs was investigated. It is demonstrated that these GILs are promising for being used as electrolytes for DSSCs and a conversion efficiency of 4.1% can be obtained under AM 1.5 sun light irradiation.

Effects of guanidinium cations on structural,optoelectronic and photovoltaic properties of perovskites

Guanidinium(GA)cations are intentionally introduced in MAPbI_(3) perovskite by considering its potential capability of stabilizing the material through plenty of hydrogen bonds and mitigating hysteresis because of the zero dipole moment.The configurations of GA cation in film and its effects on structural,optoelectronic and photovoltaic properties of perovskite have been comprehensively studied by systematically modulating the GA ratio.It has been demonstrated that moderate GA cations can effectively passivate the defect surrounding perovskite grains,yielding an enhanced efficiency as high as~19,2%in a p-i-n type planar solar cells with the GA ratio of 15%.Further increasing the GA ratio deteriorates device performance,as extra GA cations hinder grain growth and thus reduce the grain size,which facilitates the defect generation around the enhanced interface.Moreover,a new two-dimensional(2 D)layered perovskite phase that features alternating GA and MA cations in the interlayer space(ACI)appears ultimately,while the ACI phase typically suffers from slow charge transportation across the parallel PbI2 octahedral layers separated by large A-site cations.

Atom-economic macrocyclic amphiphile based on guanidinium-functionalized selenacrown ether acting as redox-responsive nanozyme

Control of self-assembly is significant to the preparation of supramolecular materials, but the control of hydration, responsiveness, dimension, catalysis of macrocyclic amphiphiles in an atom-economic manner is still a great challenge. The herein presented 527 Da low-molecular-weight macrocyclic amphiphile was fabricated by utilizing the selenium-containing crown ether as a hydrophobic motif together with guanidinium group as the hydrophilic moiety. The resulting benzo[21]crown-7 based macrocyclic amphiphile readily forms a redox-responsive solid nanoparticles in water, which can further interconnect into wrinkled pattern on-surface, as well as exhibits as a nanozyme for catalyzing disulfid bond formation. The present work highlights the great potential of guanidinium-and selenium-containing crown ethers for the control of functional assemblies.

光动力抗菌水刺棉的染整一体化制备及其性能

为解决传统抗菌非织造用品防护性能差、制备成本高和潜在毒性大等问题,以水刺棉为基材,通过低分子质量壳聚糖改性、柠檬酸共价交联和光敏剂染整一体化负载工艺,制备了具有高效广谱、抗菌耐久、安全低毒和绿色低碳的光动力抗菌水刺棉。利用紫外/可见光分光光度计、傅里叶红外光谱仪、荧光光谱仪对光动力水刺棉的化学结构和光动力学性能进行表征,通过抗菌实验探究了不同接触时间下光动力水刺棉的抗菌性能与抗菌耐久性能。结果显示:光动力水刺棉在10 min光照下能够淬灭50%以上的1,3-二苯基异苯并呋喃,属于主导能量转移的Ⅱ型光动力机制,在15 min内杀灭99%以上的金黄色葡萄球菌,在60 min内杀灭90%以上的大肠杆菌,表明功能化的水刺棉具有优异的光动力抗菌特性;此外,光动力水刺棉经光漂白和水洗使役后仍具有显著的抗菌耐久性,均可满足生物医用材料对生物安全性的要求,具有大规模制备新一代光触媒非织造用品的应用潜力。

Mononitration of phenol derivatives by guanidinium nitrate and silica sulfuric acid under mild conditions

A mixture of guanidinium nitrate and silica sulfuric acid acts as mild and heterogeneous media for the efficient mono nitration of phenolic compounds in dichloromethane at room temperature.

Effect of three kinds of guanidinium salt on the properties of a novel low-abrasive alkaline slurry for barrier CMP

The influence of three kinds of guanidinium salt on the removal rate selectivity of different materials was studied during the barrier chemical mechanical polishing （CMP） process at first. The three kinds of guanidine saltguanidine hydrochloride, guanidine nitrate and guanidine carbonate. Then we compared the effect of the three kinds of guanidine salt on the dishing, erosion and surface roughness value. In the end, the reaction mechanism was studied through electrochemical analysis. All the results indicate that there is a better performance of the slurry with guanidine hydrochloride than the slurries with the other two kinds of guanidine salt. It effectively improved the removal rate selectivity and the surface roughness under the premise of low abrasive concentration and low polishing pressure, which is good for the optimization of the alkaline slurry for the barrier CMP process.

Highly efficient and thermal stable guanidinium-based two-dimensional perovskite solar cells via partial substitution with hydrophobic ammonium

Layered two-dimensional(2D)perovskite solar cells(PVSCs)with a chemical formula of C(NH2)3(CH3NH3)3Pb3I10(n=3)have been fabricated through additive engineering,wherein stoichiometrically equivalent guanidinium(GA+)and methylammonium(MA+)serve as spacer cations.The crystallinity of the perovskite films is dramatically enhanced with proper amount of methylammonium thiocyanate(MASCN)added into the precursor solution.In addition,we substitute a small amount of MA+with hydrophobic phenylethylammonium(PEA+),which can passivate trap states of the perovskite films.As a result,the open circuit voltage increases to 1.1 V and the best power conversion efficiency(PCE)of 10.12%is yielded.Furthermore,superior thermal stability and balanced moisture stability of the PEA-substituted GA-based PVSCs are demonstrated,compared to the popular 3D MAPbI3and 2D PEA-based PVSCs.They retain approximately 80%of the original PCE after 30 d at 20%relative humidity(RH),and 50%of the original PCE after 3200 min at 85°C without any encapsulation.This work suggests a new route to achieve both heat and humidity stable PVSCs by simply mixing different spacer cations.

Comparison of Inactivation and Unfolding of Calf Intestinal Alkaline Phosphatase in Guanidinium Chloride Solution

The changes in activity and unfolding of calf intestinal alkaline phosphatase (CIP) during denaturation in guanidinium chloride solutions of different concentrations were investigated using ultraviolet difference absorption spectra and fluorescence emission spectra. Unfolding and inactivation rate constants were measured and compared. The inactivation course is much faster than that of unfolding, which suggests that the active site of CIP containing two zinc ions and one magnesium ion is situated in a limited and flexible region of the enzyme molecule, which is more fragile to the denaturant than the protein as a whole.

Preparation of Amino-functionalized Guanidinium Ionic Liquid-Modified Magnetic Materials and Application in Solid-Phase Extraction of Pollutants in Water

In the present work,a novel amino-functionalized hexaalkylguanidinium chloride ionic liquid was prepared and grafted on the surface of magnetic materials through polyethyleneimine to enrich polycyclic aromatic hydrocarbons in water in combination with HPLC equipped with an ultraviolet detector.The effect of several parameters on the extraction efficiency was investigated,including the desorption solvent,the amounts of sorbents,the extraction time,the desorption time and the salt amount.Under the optimized conditions,the method validation exhibited good linearity with correlation coefficients above 0.994 in the range of 0.2-300 ng/mL and low limits of detection and quantification of 0.05 and 0.2 ng/mL,respectively.Besides,relative recoveries were in the range of 80-120%,and the intra-day and inter-day repeatability were good with the relative standard deviations of less than 20%.Finally,the guanidinium ionic liquid modified magnetic materials were applied for the extraction of polycyclic aromatic hydrocarbons from real water samples to demonstrate the utility,and the results show that the proposed method has good prospect for effective enrichment and determination of pollutants in water.

Li/LiFePO_4 battery performance with a guanidinium-based ionic liquid as the electrolyte

A new guanidinium-based ionic liquid (IL) was investigated as a novel electrolyte for a lithium rechargeable battery. The viscosity, conductivity, lithium redox behavior, and charge-discharge characteristics of the lithium rechargeable batteries were investigated for the IL electrolyte with 0.3 mol kg 1 lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt. Li/ LiFePO 4 cells incorporating the IL electrolyte without additives showed good cycle properties at a charge-discharge current rate of 0.1 C, and exhibited good rate capabilities in the presence of a mass fraction of 10% vinylene carbonate or gamma-butyrolactone.

Self-assembly architecture of bis(guanidiniums) receptors incorporated by sulfate anions in single crystals

A novel bis(guanidiniums) receptor for the catalytic cleavage of phosphosdiester was prepared and self-assembly architecture through hydrogen bonds and electrostatic interactions among the bis(guanidiniums) receptor, the sulfate anion and water molecule was revealed by X-ray crystallographic analysis.

Crystal and molecular structure of guanidinium hexatungsto-bis(p-aminophenylarsonate)tetrah ydrate,[C(NH_2)_3]_4[(p-NH_3C_6H_4As)_2W_6O_(25)].4 H_2O

The crystal structure of a new type arylarsonic polytungstate[C(NH_)_]_4[p-NH_3C_6H_4As)_2- W_6O_(25)]·4H_O was determined by single-crystal X-ray diffraction analysis.It belongs to triclinic,space group P,with cell dimensions a=12.863(3),b=18.912(3),c=21.383(4)α=91.14(2)°,β= 93.65(3)°,γ=92.25(3)°,V=5185.9~3,Z=4,D_c=2.753g/cm^3.The intensity data were collected on an Enraf-Nonius CAD4 diffractometer with Mo Kα radiation.The positions of all tungsten and arsenic atoms were determined by direct method.The other non-hydrogen atoms were revealed by difference Fourier synthesis.The structure was refined by fullmatrix least-squares procedure to a final R value of 0.070.The crystal structure contains two similar but nonidentical molecules.Two similar anions consist of a ring of six WO_6 octahedra,which are connected with one face-sharing,two corner-sharings and three edge-sharings,and two p-aminophenylarsonic tetrahedra capped above and below the ring. In each WO_6 ring,four tungsten atoms,which are joined with edge-sharing oxygen atoms,are almost coplanar,while the two others,which are joined with face-sharing oxygen atoms,protrude out of the ring towards the same side.The two arsenic atoms in each anion are not equivalent in their bonding manner.In each anion,all non-hydrogen atoms of each organic group are in the same plane.Each molecule contains one anion,four C(NH_2)_3^+ cations and four water molecules.There are many hydrogen bonds between cations and anions throughout the whole crystal.The amino groups can accept protons,so that the charge of the resulting anion decreases and[(RAs)_2W_6O_(25)]^(4-)type complexes are formed.