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To fulfill increasing and diverse demands of cyclopentadienyl metal complexes (CpM) catalyzed asymmetric C–H activation, innovation in developing new types of chiral Cp ligands should be important. In this context, we found the structurally rigid chiral bicyclo[2.2.2]octane-fused Cp ligands originated by Vollhardt and -Halterman were efficient to enable highly enantioselective C–H activation of N -methoxybenzamides with quinones. Besides, we also designed and synthesized a class of ferrocene-based chiral Cp ligand featuring a loose chiral pocket, whose rhodium complexes exhibited high reactivity and reasonable enantioselectivity in an asymmetric intramolecular aryl amination of alkene. 1 Introduction 2 Chiral Cp Ligands Applied in Asymmetric C–H Activation 3 Chiral Bicyclo[2.2.2]octane-Fused Cp Ligands 4 Chiral Ferrocene-Derived Cp Ligands 5 Conclusion [ABSTRACT FROM AUTHOR]

Ferrocene derivatives are amongst the most promising electroactive organic electrolytes. The bottleneck problems of their application in aqueous redox flow batteries are their poor solubility and lower potential as well as the complexity of the modification methods to solve these problems. In this study, a benzenesulfonic acid group is easily introduced into the ferrocene structure by a mature diazotization reaction, and the synthesized sodium m-phenylferrocene sulfonate BASFc is used as the novel cathodic electroactive electrolyte for AORFB. The hydrophilicity and the electron-absorbing effect of the introduced benzenesulfonic group can effectively improve the water solubility and redox potential of ferrocene. Moreover, the introduction of phenyl extends the conjugated structure of ferrocene and increases its structural dimension, which may be conducive to reducing its membrane permeability and improving the structural stability to some extent. The physical structure and the electrochemical properties of BASFc are studied systematically; the feasibility of its application as a cathodic electrolyte in AORFBs is verified by assembling the half-cell and full-cell. The results verify the good electrochemical reaction kinetics of BASFc in acid electrolyte and the corresponding AORFB shows satisfactory efficiency and stability. [ABSTRACT FROM AUTHOR]

A highly efficient palladium‐catalyzed asymmetric synthesis of N‐substituted 4‐quinolones was developed via C−N coupling reaction. Various chiral quinolones were readily obtained with desirable enantioselectivity (up to 95% ee) and excellent yield (up to 99%), enabled by a simple system of palladium acetate and chiral ferrocene bisphosphine as auxiliary ligand. The corresponding racemic derivatives can also be synthesized by a transition metal‐free strategy of potassium hydroxide in DMSO. The influence of temperature on the configurational stability of these C−N axially chiral compounds was also investigated. The efficient functionalization at 3‐position further expands the application range of this synthetic technique. [ABSTRACT FROM AUTHOR]

We introduce single-chain nanoparticles (SCNPs) exclusively folded by covalently bonded ferrocene units. Specifially, we demonstrate the ability of 2-ferrocenyl-1,10-phenanthroline to fuse single-chain collapse with the concomitant introduction of a donor functionality allowing the installation of a Pd-catalytic site, affording the first heterobimetallic ferrocene-functionalized SCNP. [ABSTRACT FROM AUTHOR]

In the present paper, the photophysical properties of metallocene-4-amino-1,8-naphthalimide-piperazine molecules (1-M2+), as well as their oxidized and protonated derivatives (1−M3+, 1-M2+-H+, and 1-M3+-H+), where M = Fe, Co, and Ni, were studied via DFT and TD-DFT, employing three functionals, i.e., PBE0, TPSSh, and wB97XD. The effect of the substitution of the transition metal M on their oxidation state, and/or the protonation of the molecules, was investigated. The present calculated systems have not been investigated before and, except for the data regarding their photophysical properties, the present study provides important information regarding the effect of geometry and of DFT methodology on absorption spectra. It was found that small differences in geometry, specifically in the geometry of N atoms, reflect significant differences in absorption spectra. The common differences in spectra due to the use of different functionals can be significantly increased when the functionals predict minima even with small geometry differences. For most of the calculated molecules, the main absorption peaks in visible and near-UV areas correspond mainly to charge transfer excitations. The Fe complexes present larger oxidation energies at 5.4 eV, whereas Co and Ni complexes have smaller ones, at about 3.5 eV. There are many intense UV absorption peaks with excitation energies similar to their oxidation energies, showing that the emission from these excited states can be antagonistic to their oxidation. Regarding the use of functionals, the inclusion of dispersion corrections does not affect the geometry, and consequently the absorption spectra, of the present calculated molecular systems. For certain applications, where there is a need for a redox molecular system including metallocene, the oxidation energies could be lowered significantly, to about 40%, with the replacement of the iron with cobalt or nickel. Finally, the present molecular system, using cobalt as the transition metal, has the potential to be used as a sensor. [ABSTRACT FROM AUTHOR]

Three new heteroleptic 1,2-bis(diphenylphosphino)ethane (dppe) appended Co(III) ferrocene dithiocarbamate complexes with the formula [Co(dppe)(Fcdtc)]PF6 ((Fcdtc = N-benzyl-N-methylferrocene dithiocarbamate (Co-FcBz), N-2-methylpyridyl-N-methylferrocene dithiocarbamate (Co-FcPy) and N-ethanol-N-methylferrocene dithiocarbamate (Co-FcEtOH); dppe = 1,2-bis(diphenylphosphino)ethane) have been synthesized and characterized by microanalyses, FTIR spectroscopy, electronic absorption spectroscopy and single crystal X-ray diffraction. Single crystal X-ray diffraction revealed that the geometry around Co(III) in the Co-FcBz and Co-FcEtOH complex cations is distorted octahedral and satisfied by four sulfur atoms of two dithiocarbamate ligands and two phosphorus atoms of the dppe ligand. The weak interactions existing in Co-FcBz and Co-FcEtOH have been addressed with the help of Hirshfeld surface analysis. The electronic absorption spectra of all three compounds display bands in the regions of ∼400–500 nm and ∼500–750 nm which are due to the d–d transition of ferrocene and Co(III), respectively. These compounds have been used as photo-sensitizers in dye-sensitized solar cells (DSSCs). Experiments revealed that amongst all three sensitizer-based DSSC set-ups, the assembly fabricated using Co-FcEtOH exhibited the best photovoltaic performance with 3.89% efficiency (η), a short circuit current (Jsc) of 9.15 mA cm−2, an open circuit voltage (Voc) of −0.680 V and an incident photon-to-current conversion efficiency of 49%. Also, the ageing experiment for the DSSC set-up fabricated using Co-FcEtOH revealed that after 100 h, the set-up retained 97% of its efficiency, which indicates that such a class of molecular systems can be used as apt sensitizers for DSSC fabrication. [ABSTRACT FROM AUTHOR]

The development of new and efficient chiral extractants has always been the research hotspot and difficulty in the field of chiral extraction. Josiphos, a famous ferrocene derivative catalyst, is employed as a chiral extractant in enantioseparation of amino acid and mandelic acid enantiomers. The influences of metal ions, organic solvents, pH of the aqueous solution, extractant concentrations, and extraction temperature on enantioselectivities are systematically studied. The result reveals that Josiphos‐Pd has good capabilities to enantioseparate 4‐nitro‐phenylalanine (Nphe), 3‐chloro‐phenylglycine (Cpheg), and mandelic acid (MA) with separation factors (α) of 3.30, 2.65, and 2.18, respectively. The pH of the aqueous phase and Josiphos‐Pd concentration affect the extraction significantly, whereas extraction temperature shows little influence. After optimizing by response surface method, the mathematical models for extractions are established. And the highest experimental performance factors (pf) for Nphe, Cpheg, and MA are 0.1843, 0.1335, and 0.08884, respectively. [ABSTRACT FROM AUTHOR]

4‐Ferrocenyl‐6,7‐dimethoxy‐3,4‐dihydrocoumarin (3) was synthesized by intermolecular hydroarylation of phenol from β‐ferrocene acrylic acid, and structure has been thoroughly characterized and confirmed by analysing X‐ray single‐crystal data. Compound 3 serves as highly selective fluorescent probe towards explosive picric acid (PA) through quenching of fluorescence in aqueous media. Probe 3 ensures high selectivity for PA in the background presence of various nitroaromatics, anions, cations and some phenols. The LoD for PA has been estimated to be 25.0 ppb using fluorescent probe 3. Binding stoichiometry and binding site of 3 towards PA have been supported by Job's plot, ESI‐mass, performing NMR titration and eventually by developing a model compound 4‐ferrocenyl‐3,4‐dihydrocoumarin 4, which strongly suggested 6,7‐dimethoxy groups as best probable binding site for PA. Overall, present approach deals with development of a ferrocenyl‐dihydrocoumarin conjugate for highly selective and ultrasensitive 'turn‐off' fluorescent probe for PA, which has been well‐supported through rational spectral analyses as well as through synthesizing a model compound. [ABSTRACT FROM AUTHOR]

A ratiometric electrochemical aptasensor based on gold nanoparticles (AuNPs) functionalization and hybridization chain reaction (HCR) assisted signal amplification has been for the first time designed for the detection of streptomycin (STR). The double-stranded DNA (dsDNA) formed by the hybridization of ferrocene (Fc)-labeled STR aptamer (Apt) and capture probe (CP) is first immobilized on the gold electrode (GE) surface via Au–S reaction. The specific binding of the target and Apt results in numerous Fc detachment from the sensing interface. Then, the remaining single-stranded CP is combined with AuNPs modified with initiator DNA (iDNA) by auxiliary DNA (aDNA). Among them, the iDNA triggers HCR between two hairpin probes (H1/H2), thus capturing a large number of methylene blue (MB) electrochemical probe, which generates a strong electrochemical signal of MB and a weak electrochemical signal of Fc. Signals are collected by square wave voltammetry (the potential window ranging from -0.5 V to 0.6 V, vs. Ag/AgCl), and the oxidation peak currents at -0.200 V (MB) and 0.416 V (Fc) are recorded. The use of the ratiometric method has effectively improved the accuracy and reliability of the analysis. The successful application of AuNPs and HCR greatly improves the sensitivity of the sensor, and the detection limit is as low as 0.08 pM. It can sensitively determine STR in the range 0.1 pM to 10 nM. In addition, the designed aptasensor has been successfully applied to the detection of STR in milk and honey samples. [ABSTRACT FROM AUTHOR]

Single-atom nanozymes (SAzymes) have drawn ever-increasing attention due to their maximum atom utilization efficiency and enhanced enzyme-like activity. Herein, a facile pyrolysis strategy is reported for the synthesis of the iron–nitrogen–carbon (Fe-N-C) SAzyme using ferrocene trapped within porous zeolitic imidazolate framework-8 (ZIF-8@Fc) as a precursor. The as-prepared Fe-N-C SAzyme exhibited exceptional oxidase-mimicking activity, catalytically oxidizing 3,3′,5,5′-tetramethylbenzidine (TMB) with high affinity (Km) and fast reaction rate (Vmax). Taking advantage of this property, we designed two colorimetric sensing assays based on different interaction modes between small molecules and Fe active sites. Firstly, utilizing the reduction activity of ascorbic acid (AA) toward oxidized TMB (TMBox), a colorimetric bioassay for AA detection was established, which exhibited a good linear range of detection from 0.1 to 2 μM and a detection limit as low as 0.1 μM. Additionally, based on the inhibition of nanozyme activity by the thiols of glutathione (GSH), a colorimetric biosensor for GSH detection was constructed, showing a linear response over a concentration range of 1–10 μM, with a detection limit of 1.3 μM. This work provides a promising strategy for rationally designing oxidase-like SAzymes and broadening their application in biosensing. [ABSTRACT FROM AUTHOR]

Lysozyme (Lyz) is found in animal and human bodily fluids, and is frequently utilized as a biomarker for various diseases. Even trace amounts of Lyz in food can potentially trigger adverse immune system reactions in sensitive individuals. Therefore, it is very important to monitor Lyz concentration in foods for safety. In this study, a simple and convenient electrochemical sensor for Lyz detection was prepared by modifying gold nanoparticles (AuNPs) and ferrocene dicarboxylic acid (Fc(COOH)2) on a glass carbon electrode (GCE), which was characterized fully by various electrochemical methods and field emission scanning electron microscope (FESEM). The proposed method utilized Fc(COOH)2 as a probe and AuNPs as an electron transfer medium to improve the sensor's current response performance. Under optimal conditions, the sensor was used to detect Lyz with a linear range from 0.10~0.70 mmol·L−1 with a sensitivity of 50.55 μA·mM−1·cm−2, and a limit of detection (LOD) of 0.07 mmol·L−1. In the standard addition experiment of food samples (egg white), a total R.S.D. of less than 6.75% and an average recovery between 95.45% and 102.62% were obtained. [ABSTRACT FROM AUTHOR]

The functionalization of (R,R)-S,S′-di-tert-butylferrocene-1,1′-disulfoxide by deprotolithiation-electrophilic trapping sequences was studied towards polysubstituted, enantiopure derivatives for which the properties were determined. While the 2,2′-disubstituted ferrocene derivatives were obtained as expected, subsequent functionalization of the 2,2′-di(phenylthio) and 2,2′-bis(trimethylsilyl) derivatives occurred primarily at the 4- or 4,4′-positions. This unusual regioselectivity was discussed in detail in light of pKa values and structural data. The less sterically hindered 2,2′-difluorinated derivative yielded the expected 1,1′,2,2′,3,3′-hexasubstituted ferrocenes by the deprotometallation-trapping sequence. Further functionalization proved possible, leading to early examples of 1,1′,2,2′,3,3′,4,4′-octa, nona and even decasubstituted ferrocenes. Some of the newly prepared ferrocene-1,1′-disulfoxides were tested as ligands for enantioselective catalysis and their electrochemical properties were investigated. [ABSTRACT FROM AUTHOR]

A series of redox‐responsive ferrocenyl‐substituted boranes and boronic esters were synthesized. Oxidation of the ferrocenyl ligand to the ferrocenium resulted in a drastic increase in the Lewis acidity beyond the strength of SbF5, which was investigated experimentally and computationally. The resulting highly Lewis acidic boron compounds were used for catalytic C−F and S−F bond activation. [ABSTRACT FROM AUTHOR]

Two receptor molecules 1 and 2 (where 1 = 1-(ferrocenylmethyl)-2-ferrocenyl-5-methyl-1Hbenzo[ d]imidazole and 2 = 2-ferrocenyl-5-methyl-1H-benzo[d]imidazole) having the capability of sensing cations and anions have been synthesized and characterized by FT-IR, NMR (1H, 13C, and DEPT), elemental analysis and ESI Mass spectral analysis. Receptor 1 has been characterized by single-crystal X-ray diffraction studies. The optical and electrochemical studies confirm the multichannel recognition of cations and anions with excellent selectivity and sensitivity towards Sn2+ by receptor 1 and Sn2+/Cu2+ by receptor 2 using acetonitrile solvent. Receptor 2 having an anion binding site shows selective binding towards F- ions via electrostatic attraction. From the UV-visible studies, the binding constant for Sn2+ with receptor 2 obtained was Kb = 3.2 x 10³ M-1. The antimicrobial activities of 1 and 2 were studied and the zone of inhibition, MIC, and MBC/MFC results suggest that receptor 1 has more significant activity than 2, with potent antifungal properties. The cytotoxic activity of receptors 1 and 2 was tested with the liver cancer cell line (HepG2) by MTT assay and the IC50 values displayed moderate cytotoxicity for receptors 1 and 2 at 32.27 µM and 41.43 µM, respectively. [ABSTRACT FROM AUTHOR]

Carbon-carbon bond formation, condensation or click chemistry reactions were used to synthesize novel bowl-shaped sumanene-ferrocene conjugates, along with the extended p-electron framework in good yields. For the first time, the present study uses sumanene derivatives tris-substituted at the benzylic positions as the materials to begin the study on the click chemistry or the metal-catalyzed coupling reactions, Suzuki-Miyaura or Sonogashira couplings. The synthesized conjugates exhibited the property of selective recognizing cesium cations. As a result, this led to the development of highly sensitive and selective fluorescent or electrochemical sensors dedicated to the recognition of cesium cations (Cs+) in water. We successfully designed the Cs+ electrochemical sensors, which exhibited an acceptable limit of detection (LOD) values at 0.05-0.38 µM. Spectrofluorimetry, voltammetry, and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) were used to perform the selectivity studies. The results revealed that the designed sensors are highly Cs+-selective. This work significantly contributes to the design of new methods of sumanene modification. It also provides further information on the electrochemical properties and innovative applications of metallocene-tethered sumanene derivatives. [ABSTRACT FROM AUTHOR]

The development of a simple and convenient noninvasive salivary glucose sensor to replace the needle-prick blood collection process can not only enhance early detection and diagnosis but also reduce excess medical care costs due to delayed treatment. This study presents a noninvasive sensor based on a ferrocene/ZnO/nitrogen-incorporated nanodiamond/Si heterojunction structure to measure glucose in saliva. The sensing electrode based on a heterojunction structure composed of ferrocene (FC), Bidens-like zinc oxide (b-ZnO), and nitrogen-incorporated ultra-nanocrystalline diamond (NUNCD) films, which is a kind of nitrogen-incorporated nanodiamond, was constructed on a silicon (Si) substrate. Herein, FC and b-ZnO act as a mediator and a specific surface area promoter, respectively, and NUNCD provides a good nucleation site and conducting path. Glucose oxidase (GOx) was introduced into the system to play the role of enzyme to catalyze the reaction and increase the electrode selectivity. The FC/b-ZnO/NUNCD/Si sensor exhibited superior performance in glucose measurements within the linear ranges (1) 20–100 μM (R2 = 0.9717) with a sensitivity of 1125.18 μA/(mM cm2) and (2) 20–600 μM (R2 = 0.9926) with a sensitivity of 804.11 μA/(mM cm2). Additionally, the sensor has a sensitivity of 1012.35 μA/(mM cm2) within the range 50–400 μM (R2 = 0.9912) for artificial saliva. [ABSTRACT FROM AUTHOR]

Substituents can be used to efficiently modify the coordination and catalytic behaviour of phosphine ligands. In this article, we analyse how substituents affect the properties of ferrocene acylphosphines FcC(O)PR2 (1a–d), where PR2 is PPh2 (1a), PCy2 (1b), PAd2 (1c) and PCg (1d; Fc = ferrocenyl, Cy = cyclohexyl, Ad = 1-adamantyl, and PCg = 1,3,5,7-tetramethyl-2,4,6-trioxa-8-phosphaadamantane-8-yl). The 31P–77Se scalar coupling constants (1JPSe), determined for the corresponding phosphine selenides FcC(O)P(Se)R2 (2a–d), suggest that the basicity of the phosphine groups increases with the donor ability of the substituents R, as expected. Au(I) complexes [AuCl(1-κP)] (3a–d), obtained by replacing the dimethylsulfide ligand in [AuCl(SMe2)] with acylphosphines 1a–d, were tested in Au-catalysed alkyne hydration and intramolecular cyclisation of N-propargyl benzamide to yield 5-methylene-2-phenyl-4,5-dihydrooxazole. The collected results indicate that the highest reaction yields were generally obtained using catalysts derived from acylphosphines bearing the electron-donating aliphatic substituents 1b and 1c. From a wider perspective, the carbonyl moiety in the acylphosphines FcC(O)PR2 appears to lower steric crowding around the phosphorus atom (especially for compounds with bulky R substituents) and counterbalances the electron-donating effect of the ferrocenyl moiety. [ABSTRACT FROM AUTHOR]

A family of planar chiral indene-fused ferrocenes were prepared through an intramolecular asymmetric C–H arylation in excellent yields (up to 99%) with excellent enantioselectivities (up to 99% ee). They were thereafter successfully transformed to chiral ferrocenyl phosphines, featuring both planar and central chiralities, in good yields (up to 83%) and excellent diastereoselectivities (up to 99% de) through highly diastereoselective phosphination. This protocol offers a general method for planar and central chiral ferrocenyl phosphines. The potential applications of the newly developed ligands were demonstrated by a Pd-catalyzed enantioselective allylic alkylation reaction, in which high enantioselectivity (92% ee) and good yield (89%) were obtained. [ABSTRACT FROM AUTHOR]

Energy-relevant small molecule activations and related processes are often multi-electron in nature. Ferrocene is iconic for its well-behaved one-electron chemistry, and it is often used to impart redox activity to self-assembled architectures. When multiple ferrocenes are present as pendant groups in a single structure, they often behave as isolated sites with no separation of their redox events. Herein, we study a suite of molecules culminating in a self-assembled palladium(II) truncated tetrahedron (TT) with six pendant ferrocene moieties using the iron(III/II) couple to inform about the electronic structure and, in some cases, subsequent reactivity. Notably, although known ferrocene-containing metallacycles and cages show simple reversible redox chemistry, this TT undergoes a complex multi-step electrochemical mechanism upon oxidation. The electrochemical behavior was observed by voltammetric and spectroelectrochemical techniques and suggests that the initial Fc-centered oxidation is coupled to a subsequent change in species solubility and deposition of a film onto the working electrode, which is followed by a second separable electrochemical oxidation event. The complicated electrochemical behavior of this self-assembly reveals emergent properties resulting from organizing multiple ferrocene subunits into a discrete structure. We anticipate that such structures may provide the basis for multiple charge separation events to drive important processes related to energy capture, storage, and use, especially as the electronic communication between sites is further tuned. [ABSTRACT FROM AUTHOR]

Manipulating intracellular levels of reactive oxygen and nitrogen species (RONS) is of great potential for cancer treatment. Inspired by the natural mechanism of a radical storm in inflammatory cells via activated and regulatable biocatalysis, the authors herein report a self‐powered nanozyme that can enable RONS production in tumor cells via cascade reactions. The nanozymes are constructed via glucose oxidase (GOx)‐templated inverse microemulsion polymerization from acrylamide, arginine‐acrylamide, ferrocene‐acrylate, and N,N′‐bis(acryloyl)cystamine, followed by surface coating with hyaluronic acid. After targeted delivery into cancer cells, the nanozymes are dissociated by intracellular glutathione to release GOx, which decomposed glucose to generate gluconic acid and H2O2. Under such acidified conditions, H2O2 efficiently oxidized pendant arginine residues to produce nitric oxide , transformed into a highly toxic hydroxyl radical and superoxide anion via ferrocene‐mediated Fenton reaction and Haber–Weiss cycle, and simultaneously generated peroxynitrite anion via reaction between NO and ·O2−, thus provoking the RONS radical storm to effectively eradicate A549 tumor cells both in vitro and in vivo. This nature‐inspired enzyme‐chemical dynamic therapy may provide a promising modality for anti‐cancer treatment. [ABSTRACT FROM AUTHOR]

First representatives of chiral ferrocenophanes have been synthesized from bispidines. Their struc-ture in solution has been found to be similar to the structure of previously reported achiral ferrocenophane. [ABSTRACT FROM AUTHOR]

This work describes the facile designing of three conjugated microporous polymers incorporated based on the ferrocene (FC) unit with 1,4-bis(4,6-diamino-s-triazin-2-yl)benzene (PDAT), tris(4-aminophenyl)amine (TPA-NH2), and tetrakis(4-aminophenyl)ethane (TPE-NH2) to form PDAT-FC, TPA-FC, and TPE-FC CMPs from Schiff base reaction of 1,1′-diacetylferrocene monomer with these three aryl amines, respectively, for efficient supercapacitor electrodes. PDAT-FC and TPA-FC CMPs samples featured higher surface area values of approximately 502 and 701 m2 g−1, in addition to their possession of both micropores and mesopores. In particular, the TPA-FC CMP electrode achieved more extended discharge time compared with the other two FC CMPs, demonstrating good capacitive performance with a specific capacitance of 129 F g−1 and capacitance retention value of 96% next 5000 cycles. This feature of TPA-FC CMP is attributed to the presence of redox-active triphenylamine and ferrocene units in its backbone, in addition to a high surface area and good porosity that facilitates the redox process and provides rapid kinetics. [ABSTRACT FROM AUTHOR]

ansa-Ferrocenes with pyrazabole bridges are chemically robust entities and therefore suitable building blocks for the synthesis of rigid-rod polymers that combine redox-active Fe(II) centers and beltene-like π faces. The specific monomers we developed bear OEt groups at both tetracoordinated boron atoms (for solubility reasons) and ethynyl substituents at the 4-positions of the two pyrazole rings. Polymerization was accomplished by a condensation reaction with 1,4-diiodobenzene using a Sonogashira–Hagihara-type protocol. As a result, oligomers with a number-average molecular weight of Mn = 7.6 kDa and dispersity of Ð = 1.55 were obtained, suggesting an average chain length of about 14 repeating units based on gel permeation chromatography analysis in THF relative to narrow polystyrene standards. The molecular weight determination was complemented by MALDI-TOF mass spectrometry and (heteronuclear) NMR spectroscopy to verify the intact pyrazabole monomer repeat units and the nature of the end groups. The oligomers were further characterized by UV–vis spectroscopy and cyclic voltammetry, which demonstrated the successful synthesis of a new class of redox-active materials. [ABSTRACT FROM AUTHOR]

The title compound, [Fe(C5H5)(C21H24NO2)], which is produced by the oxidation of 1-(4-tert-butylphenyl)-2-ethyl-3-ferrocenylpyrrole, crystallizes as a racemic mixture in the centrosymmetric space group P21/n. The central heterocyclic pyrrole ring system subtends dihedral angles of 13.7 (2)° with respect to the attached cyclopentadienyl ring and of 43.6 (7)° with the major component of the disordered phenyl group bound to the N atom. The 4-tertbutylphenyl group, as well as the non-substituted Cp ring are disordered with s.o.f. values of 0.589 (16) and 0.411 (16), respectively. In the crystal, molecules with the same absolute configuration are linked into infinite chains along the baxis direction by O--H· · ·O hydrogen bonds between the hydroxy substituent and the carbonyl O atom of the adjacent molecule. [ABSTRACT FROM AUTHOR]

Ferrocene and its derivatives are very useful in the fields of chemistry, biomedicine and materials. Herein, a ferrocene derivative was synthesized in one step from benzotriazol-1-yl-oxytripyrrolidino-phosphonium hexafluorophosphate and ferrocenecarboxylic acid. Its accurate structure was determined by 1H and 13C NMR and further confirmed by X-ray diffraction analysis of the corresponding single crystal. [ABSTRACT FROM AUTHOR]

The reaction of 1,1′-dibromoferrocene with three equivalents of LiTMP and Me2S2 produces a product mixture, from which 1,1′-dibromo-2,2′-bis(methylthio)ferrocene (4) can be isolated in moderate yield. Further treatment of the isolated compound 4 with two equivalents of LiTMP and Me2S2 also produced a mixture, from which the title compound 7 could be isolated. A crystal structure determination of 7 shows that the two cyclopentadienyl rings are oriented in such a way that a maximum number of S...Br contacts results. Intermolecular S...Br contacts, supported by S...S contacts, lead to a 1D-chain polymer in [1 0 0] direction. [ABSTRACT FROM AUTHOR]

We have investigated the electronic and transport properties of a series of 2D Fc(X)n–MoS2 (Fc=Fe(Cp)2; X=SiH2, CH2, CH=CH, or C≡C; n = 1 or 2) systems by using ferrocene derivatives Fc(X)n to be grafted onto a MoS2 surface. Calculations have been carried out by density functional theory (DFT) and nonequilibrium Green's function (NEGF) methods. All these Fc(X)n–MoS2 give type-II heterostructures, and the grafted Fc(X)n behaves as a quantum dot-like group. No matter which Fc(X)n group is introduced, the conductivity is improved. The current magnitudes at a certain bias voltage follow the sequence of Fc(C≡C)-MoS2 ≈ Fc(CH=CH)-MoS2 > Fc(SiH2)2-MoS2 ≈ Fc(SiH2)-MoS2 > Fc(CH2)2-MoS2 ≈ Fc(CH2)-MoS2, corresponding well to the abilities of supplying electrons from the (X)n group to MoS2. The armchair direction exhibits a larger current by about 4 times compared to the zigzag direction. A distinct NDR behavior is found for the Fc(C≡C)-MoS2, meaning that the transport channel can be electrically switched from the off state to the on state, and again turned to the off state. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has made the world aware of how crucial the development of cost-effective and scalable antiviral drugs is. Here we report the synthesis of caffeine-based 8-[(ferrocenyl)(hydroxy)methyl]-1,3,7-trimethyl-3,7-dihydro-1H-purine-2,6-dione (FHC), and its use as an inhibitor of protease (Mpro), an essential enzyme for SARS-CoV-2 viral replication. FHC was modelled through density functional theory to get an insight of its properties, and fully characterized through conventional techniques. Its activity against Mpro was investigated using a molecular docking approach, showing excellent binding affinity to the catalytic dyad of His41 and Cys145 and the active sites of Mpro with energies score ranging from -6.7 to -7.0 kcal/mol. The affinity of conformers to bind to the active pocket was 44%. Based on a detailed investigation, it appears that FHC has a safe ADME profile, and that it could be a potential inhibitor for Mpro of SARS-CoV-2. [ABSTRACT FROM AUTHOR]

Intramolecular electronic communication between electrochemically active groups connected by a bridging moiety can be modified through small changes in the spatial disposition of the redox active moieties and/or by the nature of the central core. In this study, chiral bio-based compounds, namely isomannide and isosorbide, were employed as cheap and easy-to-functionalize chiral scaffolds to bridge two ferrocenyl electroactive moieties. The crystal structures of both bis-ferrocenyl diester complexes were studied and they showed that the chirality of the bridge results in an open or tight helical crystal packing. The electron communication between the two electroactive units in the mixed valent monocations was also investigated using electrochemistry (cyclic voltammetry and differential pulsed voltammetry), and spectroelectrochemistry in the UV-Vis NIR. A computational study through time-dependent DFT was also employed to gain greater insight into the results obtained. [ABSTRACT FROM AUTHOR]

Since the discovery of classical chiral oxazoline ferrocene ligands in 1995, they have become pivotal in transition metal-catalyzed asymmetric transformations. Over the past decade, a notable evolution has been observed with the emergence of siloxane-substituted oxazoline ferrocenes, demonstrating significant potential as chiral ligands and catalysts. These compounds have consistently delivered exceptional results in diverse and mechanistically distinct transformations, surpassing the capabilities of classical oxazoline ferrocene ligands. This review meticulously delineates the research progress on siloxane-substituted oxazoline ferrocene compounds. It encompasses the synthesis of crucial precursors and desired products, highlights their achievements in asymmetric catalysis reactions, and delves into the exploration of the derivatization of these compounds, emphasizing the introduction of ionophilic groups and their impact on the recovery of transition metal catalysts. In addition to presenting the current state of knowledge, this review propels future research directions by identifying potential topics for further investigation concerning the siloxane-tagged derivatives. These derivatives are poised to be promising candidates for the next generation of highly efficient ligands and catalysts.

The molybdenum-catalyzed enantioselective ring-closing metathesis/kinetic resolution of a series of racemic planar-chiral 1,1′-diallylferrocene derivatives was reinvestigated utilizing the method of generating catalytically active chiral molybdenum-alkylidene species in situ, which allowed us to examine a variety of chiral molybdenum-alkylidene metathesis precatalysts in the present asymmetric reaction. With the catalyst screening experiments conducted in this study, the more practical reaction conditions, including a choice of a proper chiral molybdenum precatalyst, giving planar-chiral ferrocenes of higher enantiomeric purity and better chemoselectivity could be optimized.

Two ferrocene derivatives, namely, 1,2-(tetramethylene)-ferrocene and 1,2,1′,2′-bis(tetramethylene)-ferrocene, were synthesized in a four-step reaction sequence starting from ferrocene. Friedel–Crafts acylation of ferrocene using succinic anhydride gave mono- or bis(3-carboxypropinoyl)-ferrocene depending on the stoichiometry of succinic anhydride. The reduction of the keto groups to methylene followed by ring-closing using trifluoroacetic anhydride gave 1,2-(α-ketotetramethylene)-ferrocene or 1,2,1′,2′-bis(α-ketotetramethylene)-ferrocene. The diastereomeric mixture of the latter diketones was separated using column chromatography, characterized via single-crystal X-ray analysis, and assigned its stereochemistry. Reduction of the keto groups to methylene under Clemmensen conditions gave homoannular mono- or bis(tetramethylene)-ferrocene derivatives. The molecular structure of 1,2-(tetramethylene)-ferrocene revealed that the ipso carbon atoms of the cyclopentadienyl group are 0.023(3) Å farther away from Fe(II) compared to the remaining three carbon atoms. Both complexes exhibit lower half-wave oxidation potentials than ferrocene, possibly due to the electron-releasing effects of the tetramethylene bridges.

This study investigates novel ferrocene-based electrochemical sensors for metal cation detection via the design, synthesis and characterisation of ferrocene derivatives. Specifically, this research determines the redox potentials of ferrocene versus decamethylferrocene to provide insight into the redox potential variations. The investigation also examines how electrochemical oxidation of the ferrocene moiety can modulate host affinity for transition metal cations via effects such as electrostatic interactions and changes to coordination chemistry. Metal ion coordination to receptors containing functional groups like imine and quinoline is explored to elucidate selectivity mechanisms. These findings advance the fundamental understanding of ferrocene electrochemistry and host–guest interactions, supporting the development of improved cation sensors with optimised recognition properties, sensitivity and selectivity. Overall, this work lays the necessary groundwork for applications in analytical chemistry and sensor technologies via customised ferrocene-derived materials.

In this work, we developed two new polyfunctional hybrid systems in which the presence of Fc redox “antennas” on peptide scaffolds allows for a modulation of their electronic properties. Specifically, we synthesized two helical hexapeptides containing four Aib (α-amionoisobutyric acid) and two L-Dap (2,3-diamino propionic acid) residues. L-Dap side chains were then functionalized with Fc moieties. The structures of the two 310 helical peptides, namely Z-Aib-L-Dap(Fc)-Aib-Aib-L-Dap(Fc)-Aib-NH-iPr and Z-Aib-L-Dap(Fc)-Aib-L-Dap(Fc)-Aib-Aib-NH-iPr, were investigated by X-ray diffraction, 2D-NMR, CD and IR spectroscopies. Due to the helical conformation, in Z-Aib-L-Dap(Fc)-Aib-Aib-L-Dap(Fc)-Aib-NH-iPr, the Fc groups are located on the same face of the helix, but in Z-Aib-L-Dap(Fc)-Aib-L-Dap(Fc)-Aib-Aib-NH-iPr, they are located on opposite faces. Surprisingly, two bands were found through DPV for Z-Aib-L-Dap(Fc)-Aib-L-Dap(Fc)-Aib-Aib-NH-iPr, indicating an electrostatic interaction between the Fc groups despite their longer reciprocal distance with respect to that in Z-Aib-L-Dap(Fc)-Aib-Aib-L-Dap(Fc)-Aib-NH-iPr. CD experiments at different concentrations evidenced aggregation for Z-Aib-L-Dap(Fc)-Aib-L-Dap(Fc)-Aib-Aib-NH-iPr, even at high dilutions, thus suggesting that the Fc-Fc electrostatic interaction could be of an intermolecular nature.

The title compound 1-ferrocenyl-3,3-bis(methylthio)prop-2-en-1-one (1), a key intermediate in the synthesis of ferrocene-containing heterocycles, has been characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic space group P21/c with 8 molecules in the unit cell. Unit cell parameters are 12.8159(10), 10.8121(9), and 20.8411(16) Å for a, b and c, respectively with β = 98.985(4)°. There are two distinct molecules in the asymmetric unit (A and B). Both molecules display a nearly eclipsed conformation with respect to the individual intramolecular cyclopentadienyl units in addition to close intramolecular contacts between the carbonyl O atom and one S atom of the bis-methylthiol functionality. Close intermolecular contacts involving A and B are noted with respect to S⋯H interactions between a thiol-S and the substituted Cp group in addition to C=O∙∙∙HC= interactions with the ene-moiety and a H atom located on one of the thiomethyl groups. [ABSTRACT FROM AUTHOR]

Abstract Extensive research have been devoted to the exploration of multifunctional theranostic agents for cancer, but the poor tumor specificity and unsatisfactory treatment efficacy are some of the critical obstacles for their clinical translations. Herein, ferrocene‐carbon dot‐crosslinked nanoparticles (Fc‐CD NPs) were designed and fabricated for achieving highly specific and photothermal‐augmented chemodynamic therapy (CDT). The Fc‐CD NPs were found not only to inherit the immanent fluorescence, photoacoustic, and photothermal properties of carbon dots (CDs), but also be endowed with CDT that could occur selectively in tumor microenvironment (TME) due to the presence of Fc for triggering Fenton reaction. Moreover, the enlarged particle size of Fc‐CD NPs facilitated their effective accumulation at tumor sites, thus realizing great improvement for antitumor treatment outcomes. Once docking at tumor and being exposed to 660 nm laser irradiation, significantly amplified CDT effect of Fc‐CD NPs was observed due to heat‐accelerating generation of reactive oxygen species (ROS). More interestingly, since the produced ROS could in turn alleviate the thermal‐resistance of photothermal therapy (PTT), the therapeutic efficiency of integrated PTT and CDT was synergized to the maximum extent. This study on the one hand provides a facile approach to fabricate CDs‐based multifunctional theranostic nanoplatform with enhanced tumor accumulation and specificity, on the other hand emphasizes the merits of synergizing mutually beneficial therapeutic modalities for more efficient cancer therapy.

Braga-Goodenough all-solid-state Na-Fc and Li-MnO2 batteries demonstrate deposition of Na and Li on the cathode during discharge. These reaction mechanisms were investigated in light of the generalized charge neutrality level and the experimental results of Braga et al., and two new types of mechanisms were proposed. The Na-Fc mechanism is represented by a multi-step C[(CE)cC]n mechanism where C is the chemical step, E is the electrochemical step, c is the catalytic (CE) step, and n denotes the number of [(CE)cC] part cycles. The nth cycle corresponds to n moles of Na and Li deposition. For Li-MnO2, two mechanisms were considered. One is the C[(CE)cC]n mechanism which is the same as Na-Fc, and the other is the C[2(CE)cC]n mechanism, which involves two consecutive (CE)c steps. In the C step of (CE)c of both mechanisms, Fc and MnO2 reduce Na+(sf) and Li+(sf) (sf - surface states) to deposit Na and Li, respectively, which are intramolecular charge transfer reactions within the adsorbed molecules. Fc and MnO2 are oxidized to inter­mediates immediately reduced to Fc and MnO2 by their anodes in the subsequent E step. Based on these mechanisms, these batteries' discharge capacity and cathode alkali metal deposition were examined in detail.

Carbendazim (CBZ) is a broad-spectrum fungicide, which is toxic to mammals. Therefore, it is very necessary to establish a sensitive detection for food safety. An experiment found that CDFe exhibited excellent catalysis for the nano-indicator reaction of HAuCl4-glyoxal to produce gold nanoparticles (AuNPs) and that the generated AuNPs have a very strong surface-enhanced Raman scattering (SERS) effect at 1613 cm−1 in the presence of Victoria blue B molecular probes, and resonance Rayleigh scattering (RRS) signals at 370 nm. The aptamer (Apt) suppressed the catalysis of CDFe to cause the SERS and RRS signals decreasing. With the addition of CBZ, the specific Apt reaction occurred to restore the catalysis of CDFe, and resulting in a linear increase in the signals of RRS and SERS. As a result, this new nanocatalytic amplification indicator reaction was coupled with a specific Apt reaction of carbendazim (CBZ), to construct a new CDFe catalytic amplification-aptamer SERS/RRS discattering assay for ultratrace CBZ, which was used to analyze CBZ in tea samples with satisfactory results. In addition, this biosensoring platform can be also used to assay profenofos.

An electrochemical chiral sensing platform based on a multi-substituted ferrocene–cuprous ion (Cu+) complex is constructed for the discrimination of electroactive amino acid (AA) isomers. Due to the opposite configurations of the AA isomers, the developed multi-substituted ferrocene–Cu+ can preferably combine with a right-handed AA (D -AA) isomer to form the ternary complex of multi-substituted ferrocene–Cu+- D -AA through π–π interactions, resulting in higher peak currents of D -AA. Therefore, the isomers of electroactive AA can be successfully discriminated. Among the tested electroactive AA isomers, the chiral sensing platform exhibits higher discrimination capability toward the isomers of tryptophan (Trp) than that of tyrosine (Tyr) and cysteine (Cys), which might be ascribed to the stronger π–π interactions between the benzene ring of the multi-substituted ferrocene and the indole ring of the Trp isomers. [ABSTRACT FROM AUTHOR]

A 1,1'‐disubstituted ferrocenyl pyrroloimidazolone with syn stereochemistry undergoes double lithiation–electrophile quench in a one‐pot procedure to give C2‐symmetric 1,1',2,2'‐tetrasubstituted products in >95 : 5 diastereomeric ratio (dr). These results represent an extension of double lithiation to access tetrasubstituted planar chiral ferrocenes for the first time to a nitrogen‐linked (pyrroloimidazolone) chiral directing group. The stereochemistry of the products was determined by X‐ray crystallography of distannane and dibromide adducts in combination with deuteration, elimination, and transmetalation experiments. Results support that products arise from selective deprotonation of the pro‐Sp position of each cyclopentadienyl (Cp) ring. [ABSTRACT FROM AUTHOR]

Two ferrocene‐based NHCs of the type fc[(NR)2C:] (1R; fc=1,1'‐ferrocenylene) containing benzylic N‐substituents were synthesised from the corresponding formamidinium compounds 1RH[BF4] by reaction with LiN(SiMe3)2. In the case of R=CH2Ph (Bn), the carbene was characterised through trapping reactions with sulfur and selenium, which afforded fc[(NBn)2CS] (1BnS) and fc[(NBn)2CSe] (1BnSe), respectively. A thermally stable carbene was obtained with R=CH2Mes (Bn*). Its reaction with sulfur and selenium afforded fc[(NBn*)2CS] (1Bn*S) and fc[(NBn*)2CSe] (1Bn*Se), respectively. Its reaction with [Rh(μ‐Cl)(COD)]2 (COD=cycloocta‐1,5‐diene), followed by substitution of the COD ligand by CO, furnished cis‐[RhCl(CO)2(1Bn*)]. In combination with IR data of cis‐[RhCl(CO)2(1Bn*)], NMR data of 1Bn*H[BF4], 1Bn* and 1Bn*Se indicate that 1Bn* is substantially more nucleophilic and more electrophilic than conventional Arduengo carbenes, exhibiting an ambiphilicity similar to that of CAACs. The crystal structures of the formamidinium salts 1RHX (X=[BF4], R=Bn, Bn*; X=Cl, R=Bn*), of the carbene 1Bn* and its AuI complex [AuCl(1Bn*)] as well as of the sulfur and selenium derivatives 1RE (E=S, Se; R=Bn, Bn*), the RhI complexes cis‐[RhCl(CO)2(1R)] (R=Bn, Bn*) and the CuI complex [CuBr(1Bn)] were determined by single‐crystal X‐ray diffraction (XRD). In addition, the crystals structures of the diimine fc(N=CHMes)2 and the diamine fc(NHBn*)2 were also determined by XRD. [ABSTRACT FROM AUTHOR]

The bioorganometallic chemistry of ferrocene has been gaining significance in recent years. This review presents ferrocene-triazole conjugates displaying significant biological properties. The conjugates have been synthesized via azide–alkyne cycloaddition reactions. The data are summarized according to the type of activity (anticancer, antibacterial and/or antifungal, antiprotozoal, and other effects). The results of studies concerning the understanding of the role of the ferrocene core in their biological activity are highlighted. While generally the mode of action of these organometallic species remains unclear, the importance of redox properties of ferrocene has been postulated in several cases. [ABSTRACT FROM AUTHOR]

Compared to their widely studied phosphine counterparts, ferrocene stibines have received only marginal attention thus far. This paper describes the synthesis of 1,1′-bis(diphenylstibino)ferrocene (1*), which is an antimony analogue of the ubiquitous dppf, and our investigations into the reactivity and coordination behaviour of this compound. Thus, distibine 1 was oxidised to stiboranes fc(SbPh2X2)2 (X = Cl, 2*; F, 6*; fc = ferrocene-1,1′-diyl) and to stibine-stiborane Ph2SbfcSbPh2F2 (5*). Compounds 2 and 6 were easily hydrolysed to produce ferrocenophanes fc[SbPh2XOSbPh2X] (X = Cl, 3*; F, 7*). Removing the halogen from 3 with silver(I) salts afforded the corresponding ferrocenophanes with O-bound oxyanions, fc[SbPh2ZOSbPh2Z] (Z = NO3, 4a*; ClO4, 4b*), which were alternatively prepared from 2 and also converted back to 2 by adding a chloride source. Through investigations into the coordination behaviour of distibine 1, the following compounds were isolated and characterised: [(μ-ClO4)2{Ag(1-κ2Sb,Sb′)}2] (8*), [Ag(1-κ2Sb,Sb′)2]X (X = ClO4, 9a; SbF6, 9b*), [(μ(Sb,Sb′)-1){(arene)MCl2}2] (10*, 11*) and [(arene)MCl(1-κ2Sb,Sb′)][PF6] (12*, 13*; 10, 12: M/arene = Ru/η6-p-cymene, 11, 13; Rh/η5-C5Me5), [(η5-C5Me5)RuCl(1-κ2Sb,Sb′)] (14), [MCl2(1-κ2Sb,Sb′)] (M = Pd, 15*; Pt, 16*), [Pd(1-κ2Sb,Sb′)2]X2 (X = BF4, 17a; SbF6, 17b*), [Pd(η2-ma)(1-κ2Sb,Sb′)] (18*; ma = maleic anhydride), [(μ(Sb,Sb′)-1)(AuCl)2] (19*), and [Au(1-κ2Sb,Sb′)2]X (X = AuCl2, 20a*; SbF6, 20b*). Inspection of the structural parameters suggested that complexes featuring 1 exhibit less sterically strained structures than their dppf analogues due to longer M–Sb and Sb–C bonds, which reduce crowding around the ligated metal centre. Cyclic voltammetry and DFT calculations revealed that the primary electrochemical oxidation of 1 is reversible and occurs at the ferrocene unit. Based on preliminary catalytic tests in Suzuki–Miyaura biaryl coupling, Pd-1 complexes exhibited a lower efficiency than their respective Pd-dppf analogues. (An asterisk indicates that the crystal structure has been determined.) [ABSTRACT FROM AUTHOR]

Graphitic spheres were synthesized by the aerosol-assisted chemical vapor deposition method (AACVD), pyrolyzing a solution of toluene, ferrocene, and thiophene at 1020 °C for 30 min. The graphitic spheres were collected from different zones of the AACVD system. The scanning electron and transmission electron micrographs (SEM and TEM) showed that the synthesized carbon material comprises a complex network containing the structures of coalesced graphitic spheres structures with diameters ranging from 0.1 to 0.8 µm. X-ray diffraction patterns of these structures revealed a slight shoulder at ~ 21 2θ, suggesting the presence of expanded graphitic materials. We have also identified a narrow peak of around 29.3 2θ for samples collected outside the condenser. From a deconvolution analysis, we identified a Raman band around 1179–1194 cm−1, attributed to sp2 and sp3 bond stretching, indicating surface functionalization. The morphology, surface chemistry, composition, and thermal stability of graphitic spheres are discussed. Additionally, we present a density functional theory study to support the structural stability of many functional groups and chemical doping based on the elements sulfur and oxygen on curved carbon structures. The HOMO and LUMO energies and the electrostatic potential from charge density of several chemical species such as C–O–C, C–COOH, O-furan, C–SH, C–SO, C–SO2, and S-doping in a C240 fullerene are discussed. [ABSTRACT FROM AUTHOR]

In this work, we designed and synthesized the Fe3O4@SiO2@(CH2)3‐Im‐bisethylFc (CH3CO2) as a new catalyst for three‐multicomponent reaction (t‐MCR), which is a silica‐coated Fe3O4 nanoparticle supported with bisethylferrocene‐containing IL. All of the prepared nanoparticles were specified using FT‐IR spectroscopy, FE‐SEM, XRD, TEM, and EDX techniques. The activity of the final modified nanoparticle as MCR catalyst was tested in the one‐pot procurement of novel pyran derivatives through a t‐MCR between 2‐[(morpholin‐4‐yl)methyl]‐5‐hydroxy‐4H‐pyran‐4‐one, malononitrile, and diversity of aromatic aldehydes. The compound 2‐[(morpholin‐4‐yl)methyl]‐5‐hydroxy‐4H‐pyran‐4‐one as a precursor, was prepared via nucleophilic substitution reaction of morpholine with chlorokojic acid. The FT‐IR, 1H, and 13C NMR spectroscopies were used for the identification of newly synthesized compounds. [ABSTRACT FROM AUTHOR]

A new ferrocene‐pyrene dyad Fc‐PYS for anion recognition was rationally designed and synthesized, in which the ferrocene and the pyrene groups were combined by the imidazolium and sulfonamide anion donors. The structure of the probe was characterized by single‐crystal X‐ray diffraction. The anion recognition performance of the probe was studied by fluorescence spectroscopy and electrochemical techniques. In acetonitrile solution, Fc‐PYS can fluorescently recognize F− and H2PO4− with different models. Upon the addition of H2PO4−, the fluorescence of Fc‐PYS was increased. However, the complexation with F− quenched its fluorescence. At the same time, Fc‐PYS showed electrochemical response toward basic anions F−, H2PO4−, and AcO− with the ferrocene‐based red/ox potential a negative shift with H2PO4− > F− > AcO−. Furthermore, the binding mechanism between Fc‐PYS and anion has been investigated in detail by 1H NMR titration. [ABSTRACT FROM AUTHOR]

Radical‐containing metallopolymers (RCMPs) represent a promising class of thermoelectric (TE) materials. Here, three RCMPs with the ferrocenyl moiety R1, R2, and R3 are synthesized. Single‐walled carbon nanotubes (SWCNTs) are used to form the composites with each of these RCMPs and the morphological, spectroscopic electrochemical, and thermoelectric properties of the three polymer composites are studied. Composite R3/SWCNT shows the highest electrical conductivity (675.7 ± 36.0 S cm−1) and power factor (174.3 ± 5.5 µW m−1 K−2) compared to R1 and R2. It is shown that when the ferrocenyl unit is incorporated into the main chain of the polymer backbone, it reveals a better TE performance than that with the ferrocenyl unit at the periphery. [ABSTRACT FROM AUTHOR]

Schiff base conductive polymers (TBOT) via a one-step Schiff-base reaction have synthesized by using o-toluidine and homobenzotrialdehyde as reaction monomers. The Schiff-base ferrocene composite electrode material (TBOT-Fc) was also prepared by doping different proportions of ferrocene during the synthesis of Schiff-base conducting polymer. The electrochemical properties of the prepared composites were tested by cyclic voltammetry (CV), constant current charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). The results revealed that the electrochemical performance of TBOT-Fc0.5 was significantly higher than that of TBOT, especially the specific capacitance reached 153.1 mAh/g at the current density of 0.5 A/g. In addition, the constructed asymmetric supercapattery device (TBO-Fc0.5//AC) had a power density of 334.8 W/kg and an energy density of 46.5 Wh/kg at a current density of 0.5 A/g. [ABSTRACT FROM AUTHOR]