Template Effect Research Articles

Engineering the Morphologies of Block Copolymer Particles from the Confined Self‐assembly within Emulsion Droplets†

Comprehensive SummaryBlock copolymers (BCPs) can automatically assemble into various regulated nanoparticles when they are confined within the emulsion droplet because of the structural frustration of polymer chains and the soft template effect of the oil/water interface. In the past few years, great efforts have been made to regulate the morphologies of the resulting BCP particles. In this review article, various strategies for tuning oil/water interfacial properties to engineer the as‐formed BCP particles were summarized. Then, the comprehensive scenarios of the applications of the resulting BCP particles were discussed. Finally, the future tendency and challenge of the self‐assembly of BCPs confined in emulsion droplet were suggested.

A DFT study on the reaction pathway involved in the metal‐ion‐templated synthesis of benzo‐21‐crown‐7(B21C7) from catechol and hexaethylene glycol ditosylate in the presence of base

AbstractThis present work explores the mechanism of the alkali metal‐ion (Na+ and K+) aided benzo‐21‐crown‐7(B21C7) formation from catechol and hexaethylene glycol di‐p‐toluenesulfonate in the presence of base [Correction added on 29 December 2022, after first online publication: benzo‐21‐crown‐7(f) has been corrected to benzo‐21‐crown‐7(B21C7).]. The density functional theory (DFT)‐based studies (in gas‐phase and in acetonitrile) have identified two SN2 steps along the reaction path, where each step is characterized by an energy barrier due to the presence of a transition state (TS). The metal‐ion template effect eases the binding between the catechol oxygen and the carbon atom holding the tosyl leaving group. This metal‐ion framework facilitates the cyclization process, which is responsible for the better yield of the crown ether. In case of K+‐coordinated system in solution, the TS dipole moment value for this step is 10 Debye higher than the corresponding reactant, whereas for Na+‐coordinated system, this difference is much smaller (~7.5 Debye). A comparison of the barrier heights of this intramolecular SN2 step in acetonitrile shows a higher value for Na+ ion system (30 kcal/mol) than that of K+‐coordinated system (22 kcal/mol). Expectedly, a higher rate constant for the cyclization has been found from the kinetics study of the latter, which is in‐line with the reported experimental results. Additionally, we have also explored the consequences of the involvement of a second metal ion in the process, a possibility, which was predicted earlier for large ring‐sized crown ethers.

Two-Dimensional Nanomaterial-Templated Composites.

ConspectusTwo-dimensional (2D) nanomaterials have attracted increasing research interest since mechanically exfoliated graphene was obtained in 2004. The ultrathin thickness and relatively large lateral size of 2D nanomaterials render them various intriguing properties such as compelling electronic properties, ultrahigh specific surface area, excellent mechanical properties, and so on. A wide range of 2D nanomaterials, including graphene and its derivatives, transition metal dichalcogenides (TMDs), metals, etc., have been prepared with different compositions, structures and (crystal) phases. Simultaneously, extensive research efforts have been devoted to exploring the potential applications of these 2D nanomaterials with enhanced performances. Hybridization of two or more nanomaterials to prepare novel composites could efficiently integrate the advantages of the individual components and thus optimize their performances for specific applications. Among various hybridization approaches, the templated synthesis method, i.e., using a presynthesized nanomaterial as a template to direct the growth of a secondary nanostructure, provides an efficient way to prepare composites with high controllability. The ultrathin thickness, large specific surface area, and versatile physiochemical properties of 2D nanomaterials make them ideal templates for constructing composites with desired structures, properties, and functions. Until now, various 2D nanomaterials have been used as templates to grow different kinds of nanomaterials, including metals, metal oxides, metal chalcogenides, metal-organic frameworks (MOFs), etc., to form 2D nanomaterial-templated composites that show potentials in various applications. In this Account, we first briefly introduce the general research background of 2D nanomaterials and the motivation for the preparation of 2D nanomaterial-templated composites. Then we summarize our progress and some other representative work on 2D nanomaterial-templated composites, with a particular emphasis on graphene-templated composites, 2D TMD-templated composites, and 2D metal-templated composites. Specifically, representative examples of the graphene-templated zero-dimensional (0D), one-dimensional (1D), and 2D composites and the emerging graphene-templated van der Waals heterostructures are described. Subsequently, typical 2D TMD-templated composites such as metal oxides, metals, and metal chalcogenides are also presented. In addition, we introduce 2D metal-templated composites and highlight that the crystal phase of the 2D metal template can play an important role in the controlled synthesis of heterostructures. Other composites constructed using 2D metal oxides, metal hydroxides, metal sulfides, and MOFs as templates are also introduced. After that, we demonstrate the potential applications of 2D nanomaterial-templated composites, including electrocatalysis, electronic devices, batteries, and so on. Finally, after a brief summary, our personal insights on the challenges and future research directions in this emerging field are also proposed.

Metal (Na+, K+, Cs+) Template Effect–Controlled Synthesis of Stereoisomers of Tetrasubstituted (Thia)calix[4]arene Derivatives Containing Sulfonatoalkyl Moieties on the Lower Rim

Metal (Na+, K+, Cs+) Template Effect–Controlled Synthesis of Stereoisomers of Tetrasubstituted (Thia)calix[4]arene Derivatives Containing Sulfonatoalkyl Moieties on the Lower Rim

Recent advances in the asymmetrical templation effect of polyoxometalate in silver clusters

The design and construction of polyoxometalate (POM)-templated silver clusters have received increasing attention, not only due to their aesthetic structures but also to their wide applications in chromatic materials, magnetism, electronics, and fluorescence. Among various POM-templated silver clusters, asymmetrically-wrapped POM–silver clusters have unusual structures: POMs have exposed surfaces and an asymmetrically-connected silver shell, which endows the clusters with distinctive properties, such as redox and electrocatalytic activities. This review summarizes recent developments in this field, highlighting the syntheses, structures, and properties of the asymmetrically-wrapped POM–silver clusters. The formation mechanisms, challenges, and perspectives of such clusters are also discussed. We believe that this review will motivate the development of the asymmetrical templation effect of POM in silver clusters.

Polymer infiltration synthesis of inorganic nanoporous coatings: Does polymer template affect their properties?

Synthesis of all-inorganic metal oxide architectures using polymer templates offers control over their thickness, porosity, and composition. Here, we provide insights into the synthesis of nanoporous zinc oxide films as a model system via infiltration of polymers that have different mechanisms of interaction with metal oxide precursors such as a polymer of intrinsic microporosity (PIM-1) and representative of the block-copolymers family (polystyrene-polyvinyl pyridine block copolymer). We investigated polymer infiltration process with both gas (diethyl zinc, DEZ, and water vapors) and solution (zinc acetylacetonate, Zn(acac)2, dissolved in ethanol) phase precursors. Using quartz crystal microbalance (QCM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses, we systematically studied the effect of polymer template and the form of the metal oxide precursors on the properties of synthesized metal oxide thin coatings. We demonstrate that the infiltration of polymer templates can be efficiently achieved using both gas phase and solution phase precursors. We show that the crystallinity of the synthesized 200 nm ZnO films is mainly affected by the state of the precursor (gas or solution phase) and does not depend on the polymer template type. In turn, the polymer type affects the surface termination of ZnO films. We demonstrate that the surface of porous ZnO coatings synthesized with BCP (here PS-P4VP) is more accessible than the surface of ZnO synthesized with PIM; however, despite the lower surface accessibility for ethanol molecules, ZnO synthesized via infiltration of PIM-1 with solution-phase precursors demonstrates the largest change in resistivity upon its exposure to ethanol vapor at room temperature.

Topologically Controlled Syntheses of Unimolecular Oligo[n]catenanes.

Catenanes are a well-known class of mechanically interlocked molecules that possess chain-like architectures and have been investigated for decades as molecular machines and switches. However, the synthesis of higher-order catenanes with multiple, linearly interlocked molecular rings has been greatly impeded by the generation of unwanted oligomeric byproducts and figure-of-eight topologies that compete with productive ring closings. Here, we report two general strategies for the synthesis of oligo[n]catenanes that rely on a molecular "zip-tie" strategy, where the "zip-tie" is a central core macrocycle precursor bearing two phenanthroline (phen) ligands to make odd-numbered oligo[n]catenanes, or a preformed asymmetric iron(II) complex consisting of two macrocycle precursors bearing phen and terpyridine ligands to make even-numbered oligo[n]catenanes. In either case, preformed macrocycles or [2]catenanes are threaded onto the central "zip-tie" core using metal templation prior to ring-closing metathesis (RCM) reactions that generate several mechanical bonds in one pot. Using these synthetic strategies, a family of well-defined linear oligo[n]catenanes were synthesized, where n = 2, 3, 4, 5, or 6 interlocked molecular rings, and n = 6 represents the highest number of linearly interlocked rings reported to date for any isolated unimolecular oligo[n]catenane.

Small-sized Ag nanoparticle stacked films promoted by sustainedly released surfactants for plasmonic broadband super absorption

Large-area, highly absorptive films stacked of uniform Ag nanoparticles (AgNPs) with sub-20 nm size were fabricated by magnetron sputtering at the presence of adhesive tape, during which O-containing compounds were sustainedly released from the adhesive glue that acted as gaseous surfactants to promote the nucleation and simultaneously suppress the coalescence of the AgNPs. Plasmonic absorbers of metal-insulator-metal (MIM) configuration with a gradient-thickness insulator layer were constructed by conformally depositing such small-sized AgNP stacked films (S-AgSFs) on alumina templates with V-shaped nanopores. The broadband optical impedance matching of this novel MIM structure enables broadband light absorption from ultraviolet to near-infrared region, by working together with the large absorption cross-section, strong interparticle plasmon coupling of closely stacking small-sized AgNPs, and the light-trapping effect of the porous template. The average absorbance reaches 96.8 % in the visible region and 86.7 % in the 200–1600 nm range, respectively, showing the great potential of this absorber for applications in antireflection, solar energy harvesting and utilizing, etc. This adhesive-tape-assisted physical vapor deposition approach is simple, cost-effective, and can be applied to various types of substrates, which will enrich the fabrication strategy of metal nanostructures with effectively controlled geometries and optical properties.

Tailored alkyl-imidazolium templating synthesis of extra-large-pore germanosilicate zeolite ITT as Baeyer-Villiger oxidation catalyst

Extra-large-pore germanosilicate zeolite ITT was prepared with several structure-tailored alkyl-substituted imidazolium templates. The effect of alkyl chain length and substitution number of template on zeolite topology structure was studied with the variation of synthesis Si/Ge ratio. 1-hexyl-3-methyl-imidazaolium (1H3M) exhibited superior templating effect on the formation of ITT structure within the widest range of synthesis Si/Ge molar ratio of about 2–6. 1H→13C CP/MAS NMR, TGA and molecular simulation results revealed that two 1H3M was occluded in the 18-ring channels per unit cell, presenting the lowest interaction energy with framework. With the combination of XRD, SEM, EDS, ICP, 29Si, 19F MAS NMR, FTIR, N2 physisorption results, it was found that the increase of synthesis Si/Ge ratio improved framework Si/Ge ratio within d4r unit to a certain degree, and in the meantime resulted in the decrease of zeolite crystallinity with the formation of some amorphous phase. ITT showed better Lewis-acid catalytic activity and lactone selectivity for B–V oxidation of 2-adamantanone than BEC, the best germanosilicate zeolite ever reported. The excellent catalytic performance was ascribed to the presence of 18-ring channels in ITT, which facilitated the diffusion of bulky ketone substrate and lactone product. The structure stability of ITT during the reaction was evaluated with the use of either aqueous H2O2 or non-aqueous tert-butyl hydroperoxide (TBHP) as oxidant.

Influences of 1-Propanol and Methanol Additives on Crystallization of Thin Amorphous Solid Water Films.

In general, randomly oriented ice crystallites are formed by heating amorphous solid water (ASW) films at ∼160 K via homogeneous nucleation. Here, we demonstrate that monolayers of methanol and 1-propanol additives incorporated in the multilayer ASW film lead to heterogeneous nucleation at the substrate interface of Pt(111), as evidenced by the occurrence of epitaxial ice growth. The mobility of water in direct contact with the Pt(111) substrate is decreased relative to that in the bulk, but it can be increased via interactions with hydrophobic moieties of alcohols that are segregated to the interfacial region. As a result, heterogeneous nucleation occurs at ca. 160 K along with homogeneous nucleation in the film interior. However, the template effect is quenched when the alcohols are in direct contact with the substrate. The methanol adspecies deposited onto the ASW film surface induces heterogeneous nucleation at a temperature as low as 145 K, but the 1-propanol adspecies has no such an effect. Their different ability of heterogeneous nucleation at the free ASW film surface, as well as their uptake behaviors in the near surface region, is associated with the hydrophobic hydration of the alcohols resulting from different lengths of the aliphatic moiety.

Getting rid of 'rain' and 'stars': Mitigating inhibition effects on ddPCR data analysis, the case study of the invasive crayfish Pacifastacus leniusculus in the streams of Luxembourg.

ddPCR is becoming one of the most widely used tool in the field of eDNA-based aquatic monitoring. Although emulsion PCR used in ddPCR confers a partial mitigation to inhibition due to the high number of reactions for a single sample (between 10K and 20K), it is not impervious to it. Our results showed that inhibition impacts the amplitude of fluorescence in positive droplets with a different intensity among rivers. This signal fluctuation could jeopardize the use of a shared threshold among samples from different origin, and thus the accurate assignment of the positive droplets which is particularly important for low concentration samples such as eDNA ones: amplification events are scarce, thus their objective discrimination as positive is crucial. Another issue, related to target low concentration, is the artifactual generation of high fluorescence droplets ('stars'). Indeed, these could be counted as positive with a single threshold solution, which in turn could produce false positive and incorrect target concentration assessments. Approximating the positive and negative droplets distribution as normal, we proposed here a double threshold method accounting for both high fluorescence droplets ('stars') and PCR inhibition impact in delineating positive droplets clouds. In the context of low concentration template recovered from environmental samples, the application of this method of double threshold establishment could allow for a consistent sorting of the positive and negative droplets throughout ddPCR data generated from samples with varying levels of inhibitor contents. Due to low concentrations template and inhibition effects, Quantasoft software produced an important number of false negatives and positive comparatively to the double threshold method developed here. This case study allowed the detection of the invasive crayfish P. leniusculus in 32 out of 34 sampled sites from two main rivers (Alzette and Sûre) and five of their tributaries (Eisch, Attert, Mamer, Wiltz and Clerve).

Optical limiting and nonlinear optical properties of Cr2O3 and WO3 based polymer nanocomposites

The optical limiting behavior of templated transition metal nanoparticles Cr2O3 and WO3 in a PMMA host at the wavelength of 1064 nm in the nanosecond regime is discussed. Optical filters were produced by chemical synthesis from the bulk. The optical limiting properties were characterized using an adequate custom-made optical setup and the third order nonlinear parameters, namely the nonlinear absorption coefficients and refractive indices were measured by the Z-scan method. The optical limiting performance improvement is clearly demonstrated for the PMMA/Cr2O3 filter bearing out a laser protection level of OD = 1.2, a factor of 4 larger than the pure PMMA filter. A significant blue shift in the nonlinear activation threshold energy occurs when WO3 or Cr2O3 are embedded in a PMMA host as the values have been subsequently pulled down from 500 µJ (pure PMMA) to 65 µJ and 23µJ, respectively. Z-scan measurements highlighted a self-defocusing effect as a result of a negative nonlinearity. Nonlinear refractive indexes in the order of n2 = −1.0X10−15cm2/Wwere calculated for the PMMA/Cr2O3 and PMMA/ WO3 systems. A nonlinear absorption coefficient as high as β = 163cm/GW was measured for the PMMA/Cr2O3 optical limiting filter while the one for PMMA/ WO3 lies 1 order of magnitude behind. It is suggested that the PMMA/Cr2O3 optical system undergoes reverse saturable absorption enhanced by excited state absorption (ESA/RSA). Besides, it is believed that multi-photons absorption (MPA) occurs in PMMA/WO3 or pure PMMA.

Positive and negative effects of graphite flake and monolayer graphene oxide templates on protein crystallization

Heterogeneous template-induced nucleation is a promising way to regulate protein crystallization events and could be employed for purification processes and crystallographic studies. Protein crystallization process with graphite and graphene oxide, as heterogeneous templates, were investigated. More than 640 hanging drops with different concentrations of Lysozyme (30, 50, 70, 100 mg/mL) and NaCl (0.7, 0.9, 1.1, 1.3, 1.5 M) were crystallised at 4 °C with or without graphite/graphene oxide templates. The induction times and crystallization process were observed under the microscope. The lysozyme in the solutions with graphite flakes nucleated faster under all the conditions than the lysozyme with equal experimental conditions without templates. The crystals preferred to grow around the edge of graphite flakes than on the flat surfaces. In the droplets with monolayer graphene oxide, more crystals appeared around graphene oxide particles, and the faster or slower nucleation processes with templates were dependent on the lysozyme and NaCl concentrations. Graphene oxide templates strongly inhibited nucleation at high lysozyme concentrations but promoted nucleation at low lysozyme concentrations. Both heterogeneous templates changed the crystal morphology and the crystallization kinetics. More crystals were observed in the solution with graphite templatesthan with graphene oxide templates and without any template.

Surface modification of glass-bottom 96-microwell plates to enhance ELISA performances

A sandwich enzyme-linked dendrimer-aptamer assay (ELDAA) has been developed using glass-bottom 96-microwell plates in order to improve the detection performances of a traditional enzyme-linked immunosorbent assay (ELISA). To this end, poly(amidoamine) (PAMAM) dendrimers were chemically immobilized onto glass-bottom surfaces of the microwells, and aptamers against a model analyte, i.e., human platelet-derived growth factor BB (PDGF-BB), were subsequently conjugated onto the microwell surfaces via the immobilized PAMAM dendrimer templates. These layer-by-layer surface modifications were characterized using fluorescence microscopy, water contact angle, X-ray photoelectron spectroscopy, and atomic force microscopy to confirm the success of each surface modification steps. Moreover, the effects of different PAMAM dendrimer templates on the overall performances of the ELDAA were also studied. Our results showed that the new ELDAA had a much broader linear detection range that was approximately 2 times of that of a commercial ELISA and a significantly lowered limit of detection that was about 4.5 more sensitive in comparison with the standard ELISA. It can be concluded that the new ELDAA offers more versatile detection performances than the traditional ELISA technique and can be readily adapted into existing ELISA workflow, therefore offering a promising and robust alternative to the ELISA technique.

From mesoscopic reconstruction to flexible meso-electronics based on nucleation control refolding rerouting of silk fibroin materials

Attributed to advanced structural characterization techniques, mesoscopic hierarchical structures as well as crystal network structures have been verified in both natural and artificial soft materials including silk fibroin materials. Notably, the close correlation between mesoscopic structures (especially the structure of crystallite and crystal network) and macroscopic properties suggests that the functionalization of SF materials could start from the mesoscopic structure reconstruction in a designed manner. This review gives an overview of recent SF materials with novel and enhanced properties which are achieved by meso doping as well as meso hybridization via directing the nucleation pathways and changing nucleation kinetics. Besides, the kinetic meso reconstruction factor λ is also put forward and emphasized to quantitatively describe the templating effects of specific templating seeds, irrespective of macromolecules or nano functional seeds. The as-acquired functionalized SF materials can be further applied to fabricate bio-compatible and degradable flexible/implantable meso electronic devices (e.g., E-skins and memristors), and applicable to on-skin long-term monitoring of human physiological conditions, in-body sensing, information processing and storage.

Synthesis, spectral, biological, and computational studies of template engineered macrocyclic metal complexes

A series of macrocyclic Cu2+, Ni2+, and Co2+ complexes was synthesized using a template reaction between triethylenetetramine and dibenzoylmethane. These complexes may be represented by the general formula [M(C21H26N4)X2], where M = Cu2+, Ni2+, and Co2+ and X = NO3ˉ, Clˉ, and CH3COOˉ. Various techniques, including elemental analysis, molar conductance, magnetic moment, PXRD, thermal investigations, EPR, IR, UV-visible, and mass spectral studies, were used to characterize the synthesized complexes. Their results suggested the distorted octahedral geometry for copper complexes and octahedral geometry for nickel and cobalt complexes. All complexes showed molar conductance in the range of 8–20 ohm−1 cm2 mol−1 that indicated the non-electrolytic nature. The DFT studies of all complexes were also performed to analyze the stability of complexes. Antibacterial activities of all complexes were also examined, and it was observed that complexes [Ni(C21H26N4)(Cl)2] and [Co(C21H26N4)(Cl)2] exhibited remarkable antibacterial activity. Moreover, complex [Co(C21H26N4)(NO3)2] showed miraculous antioxidant activity, even better than that of ascorbic acid and other complexes. The docking studies of [Ni(C21H26N4)(Cl)2] and [Co(C21H26N4)(Cl)2] were also performed to enforce the results obtained from the antibacterial study of these complexes. Furthermore, the drug-likeness property of all complexes was also evaluated with the help of ADMET studies.

Fabrication of hierarchical flower-like NiMo bimetallic catalyst for valorization of biomass platforms

The rational design of catalysts with 3D open structures is vitally important to enhance catalytic performance through exposing the active sites. Herein, the hierarchical flower-like Ni-Mo bimetallic catalyst was constructed by using levulinic acid to synthesize γ-valerolactone as the template reaction and nitrogen-rich dual ligand MOF as the self-sacrificial template. Benefiting from the anchoring effect of N–C defects, the Ni-Mo bimetallic component was uniformly dispersed on the petal-shape nanosheets. The characterization results confirmed the doped Mo facilitated the formation of NiMo-Nx and MoO2 sites, and thus improved the dispersion of Ni species and the acidity of the catalyst. Density Functional Theory (DFT) calculations results confirmed that NiMo-Nx was more conducive to the dissociation of H2 than Ni and NiMo species. And, Ni-MoO2 interface could facilitate the activation and cleavage of the C–O in carbonyl group of levulinic acid. The synergy between the hydrogenation sites (NiMo-Nx) and the Lewis acid sites (Ni-MoO2 interface) enabled the catalyst excellent performance for the valorization of levulinic acid to γ-valerolactone in aqueous phase. In addition, the reaction mechanism was given according to the reaction results and DFT calculation results.

Experimental and Theoretical Evaluation of Four NLO‐Active Divalent Transition‐Metal Complexes Supported by an Enantiomerically Pure Tetradentate Schiff Base Ligand

AbstractThis paper reports on a series of five chiral Schiff base push‐pull compounds derived from enantiomerically pure (1R,2R)‐(−)‐1,2‐diaminocyclohexane. The NiII, CuII, ZnII and PdII complexes supported by a ferrocene‐containing unsymmetrically‐substituted N2O2 quadridentate Schiff base ligand were prepared via template reactions and isolated in 74–87 % yields. A combination of EA, IR, UV/vis and 1H/13C{1H} NMR spectroscopy, HRMS spectrometry, cyclic voltammetry and single‐crystal X‐ray analysis (for the proligand 2 and its NiII derivative 3), together with computational methods (DFT and TD‐DFT) was used to fully characterize and study the properties of all products. Both 2 and 3 crystallize in the orthorhombic non‐centrosymmetric space group P212121, with two (R,R)‐(−)‐chiral carbon atoms in their structure. Second‐order nonlinear polarizabilities β have been measured by using Harmonic Light Scattering at 1.91 μm, with the Pd(II) species showing the higher NLO response of 460×10−30 esu.

Novel Synthesis of Zinc Oxide Nanoparticles from Type IV Deep Eutectic Solvents

One of the fields where DES show remarkable added-values is the synthesis of inorganic materials, in particular nanoparticles. In this field, the inherent and highly-tunable nano-homogeneities of DES structure give origin to a marked templating effect, a precious role that has led to the recent bloom of a vast number of studies exploiting these new synthesis media to prepare nanomaterials and composite structures of various kinds. In this contribution, three examples of synthesis of nanoparticles containing zinc, using metal type-IV Deep Eutectic Solvents, a pathway that has never been explored so far, is described. The prepared materials have layered shapes, and when zinc nitrate is used as DES component, pure layered ZnO is obtained, forming nanometric platelets that assemble to form flower-like aggregates. The prepared nanoparticles show intrinsic fluorescence, and are being further studied to set up sensors for the detection of various contaminants.

Synthesis of Tropine-Based Functionalized Acidic Ionic Liquids and Catalysis of Esterification.

Some traditional acidic ionic liquids (AILs) have shown great catalytic potential in esterification; meanwhile, the design and application of more new AILs are expected at present.Tropine-based functionalized acidic ionic liquids (FAILs) were synthesized to realize esterification catalysis for the first time; with aspirin synthesis as the template reaction, key influences on the substrate conversion and product yield of the synthesis, such as IL type, ratio of salicylic acid to acetic anhydride, temperature, reaction time and amount of IL, were investigated. The new tropine-based FAILs exhibited excellent performance in catalytic synthesis of aspirin with 88.7% yield and 90.8% selectivity. Multiple recovery and re-usage of N-(3-propanesulfonic acid) tropine is the cation, and p-toluenesulfonic acid is the anion. ([Trps][OTs]) shows satisfactory results. When [Trps][OTs] was used to catalyze different esterification reactions, it also showed good results. The above studies proved that ionic liquid [Trps][OTs] could serve as an ideal green solvent for esterification reaction, which serves as a suitable substitute for current catalysts.