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We introduce a novel dual redox mediator synthesized by covalently linking ferrocene dicarboxylic acid (FcDA) and thionine (TH) onto a pre-treated glassy carbon electrode. This unique structure significantly enhances the electro-oxidation of dopamine (DA) and the reduction of hydrogen peroxide (H2O2), offering a sensitive detection method for both analytes. The electrode exhibits exceptional sensitivity, selectivity, and stability, demonstrating potential for practical applications in biosensing. It facilitates rapid electron transfer between the analyte and the electrode surface, detecting H2O2 concentrations ranging from 1.5 to 60 µM with a limit of detection (LoD) of 0.49 µM and DA concentrations from 0.3 to 230 µM with an LoD of 0.07 µM. The electrode’s performance was validated through real-sample analyses, yielding satisfactory results.

We conducted an investigation into the palladium‐catalyzed carbon‐sulfur cross‐coupling reaction involving a 2‐bromothiophene derivative and potassium thioacetate as a substitute for hydrogen sulfide. This investigation utilized kinetic and computational methods. We synthesized two palladium complexes supported by the bisphosphane ligands bis(diphenylphosphino)ferrocene (DPPF) and bis(diisopropylphosphino)ferrocene (DiPPF), as well as their tentative intermediates in the catalytic cycle. Reaction rates were measured and then compared to computational predictions. [ABSTRACT FROM AUTHOR]

A series of ferrocene(Fc)‐bridged pentacene(Pc)‐dimers [Fc−Ph(2,n)−(Pc)2: n=number of phenylene spacers] were synthesized to examine the tortional motion effect of Fc‐terminated phenylene linkers on strongly coupled quintet multiexciton (5TT) formation through intramolecular singlet fission (ISF). Fc−Ph(2,4)−(Pc)2 has a relatively small electronic coupling and large conformational flexibility according to spectroscopic and theoretical analyses. Fc−Ph(2,4)−(Pc)2 exhibits a high‐yield 5TT together with quantitative singlet TT (1TT) generation through ISF. This demonstrates a much more efficient ISF than those of other less flexible Pc dimers. The activation entropy in 1TT spin conversion of Fc−Ph(2,4)−(Pc)2 is larger than those of the other systems due to the larger conformational flexibility associated with the torsional motion of the linkers. The torsional motion of linkers in 1TT is attributable to weakened metal‐ligand bonding in the Fc due to hybridization of the hole level of Pc to Fc in 1TT unpaired orbitals. [ABSTRACT FROM AUTHOR]

Hetero-bimetallic ruthenium(II) complexes (PRAFIZ and PRBFIZ) containing acetyl ferrocene (AFIZ)/benzoyl ferrocene isonicotinic hydrazone ligands (BFIZ) were synthesized and characterized by various spectral and analytical techniques. The structure of acetyl ferrocene isonicotinic hydrazone (AFIZ) and the complex PRBFIZ was confirmed by X-ray crystallography. The hydrazide ligands coordinated in a bidentate monobasic fashion using their N1 hydrazinic nitrogen and enolic oxygen atoms. The binding interactions of the ligands and complexes were examined using Calf-Thymus DNA (CT-DNA) and bovine serum albumin (BSA). Scanning Electron Microscopic (SEM) experiments clarified the efficient binding interaction of the ligands and complexes with BSA. The results of in vitro cytotoxicity studies on MDA-MB-261 breast cancer cells and A549 human lung cancer cells and cell morphological analysis results through staining assays clearly indicated the cytotoxic nature of the complexes. [ABSTRACT FROM AUTHOR]

A series of stable iron(II) bis(dicarbollide) derivatives [8,8′-(RNHC(Et)＝HN)2-3,3′-Fe(1,2-C2B9H10)2] (R = Pr, R = Ph, (CH2)2OH, (CH2)3OH, (CH2)2NMe2) was prepared starting from FeCl2 or [FeCl2(dppe)] and the corresponding nido-carboranyl amidines [10-RNHC(Et)＝HN-7,8-C2B9H11]. In a similar way, the reactions of the oxonium derivatives of nido-carborane with FeCl2 in tetrahydrofuran in the presence of t-BuOK lead to the corresponding stable oxonium derivatives iron(II) bis(dicarbollide) [8,8′-(RR′O)2-3,3′-Fe(1,2-C2B9H10)2] (RR′ = (CH2)4, (CH2)2O(CH2)2, (CH2)5; R = R′ = Et), which can be alternatively prepared by the reaction of the parent iron(II) bis(dicarbollide) with tetrahydrofuran or 1,4-dioxane in the presence of Me2SO4. The cyclic voltammetry studies of the synthesized iron(II) bis(dicarbollide) derivatives revealed that the introduction of amidinium and oxonium substituents leads to a significant increase in the Fe2+/Fe3+ redox potential relative to the parent iron(II) bis(dicarbollide). The redox potentials of the oxonium derivatives are close to the redox potential of ferrocene and somewhat lower than redox potentials of sulfonium and phosphonium derivatives of iron(II) bis(dicarbollide). [ABSTRACT FROM AUTHOR]

Metal-metal contacts, though not yet widely realized, may provide exciting opportunities to serve as tunable and functional interfaces in single-molecule devices. One of the simplest components which might facilitate such binding interactions is the ferrocene group. Notably, direct bonds between the ferrocene iron center and metals such as Pd or Co have been demonstrated in molecular complexes comprising coordinating ligands attached to the cyclopentadienyl rings. Here, we demonstrate that ferrocene-based single-molecule devices with Fe-Au interfacial contact geometries form at room temperature in the absence of supporting coordinating ligands. Applying a photoredox reaction, we propose that ferrocene only functions effectively as a contact group when oxidized, binding to gold through a formal Fe3+ center. This observation is further supported by a series of control measurements and density functional theory calculations. Our findings extend the scope of junction contact chemistries beyond those involving main group elements, lay the foundation for light switchable ferrocene-based single-molecule devices, and highlight new potential mechanistic function(s) of unsubstituted ferrocenium groups in synthetic processes. Metal-metal interfaces hold promise as contacting moieties for single-molecule devices with tunable functionality, yet the direct bonding has remained a challenge. Here, Lee et al. report the formation of Fe-Au bond without chemical ligand support in ferrocene-based molecular junctions. [ABSTRACT FROM AUTHOR]

The combination of the ferrocene moiety with gold(I) catalysis remains a relatively unexplored field. In this article, we delve into the synthesis, characterization, and potential catalytic activity of four complexes utilizing both monodentate and bidentate ferrocenyl diphenylphosphane ligands (ppf and dppf), coordinated with two gold(I) metal centers, linked by either chloride or pentafluorophenylthiolate bridging ligands. This leads to the formation of cationic "self‐activated" precatalysts capable of initiating the catalytic cycle without the need for external additives. The catalytic activity of these complexes was assessed through a model reaction in gold(I) catalysis, specifically the cyclization of a N‐propargylbenzamide to produce an oxazole. In addition, we studied and compared the influence exerted by both the phosphane and the bridging ligand on the performance of these catalysts. [ABSTRACT FROM AUTHOR]

New hetero-polynuclear coordination complexes based on a pentacoordinated Zn(II) metal center with tridentate terpyridine-based ligands and monoanionic gallates functionalized with long alkyl chains containing ferrocene units were designed, synthesized and characterized using spectroscopic and analytical methods. The complexes are mesomorphic, exhibiting columnar hexagonal mesophases. The photophysical properties in a solution and in an ordered condensed state were accurately investigated and the influence of the polarity of the solvent was evidenced. [ABSTRACT FROM AUTHOR]

By combining the switching ability of redox molecules with the unique fluorescence properties of quantum dots (QDs), a robust electrochemical fluorescence switch is developed here. This is realized by grafting CdSe/ZnS QDs on transparent indium tin oxide (ITO) substrates and, subsequently, modifying them with a Ferrocene (Fc) molecular monolayer. The application of oxidation/reduction voltage pulses to tune the Fc redox state leads to the tuning of the surface fluorescence output. Interestingly, the ON/OF ratio can be enhanced by reducing the distance between the redox active unit and the QD due to a more efficient electronic coupling. Remarkably, by defining a mixed‐valence state, a ternary switch has also been achieved. It is highlighted that the QD surface immobilization is key to realize this switch to avoid aggregation and fluorescence quenching in suspension. Hence, an efficient and versatile novel route to fabricate robust fluorescent redox switches is demonstrated, opening a wide avenue of possibilities to be explored in the field of sensing and information storage. [ABSTRACT FROM AUTHOR]

A ferrocene carboxylic acid (Fc)-doped copper–p-phthalic acid metal–organic framework material (Fc–Cu PTA) exhibited remarkably high peroxidase-mimicking activity, while Cu PTA showed nearly no peroxidase-mimicking activity. Under the enzymatic catalysis of Fc–Cu PTA as a peroxidase-mimicking nanozyme, the tested organic dyes were rapidly degraded by peroxymonosulfate. Fc–Cu PTA could be an effective catalyst for the degradation treatment of dye-polluted water and soil sources, and potentially for other peroxidase-related applications as well. [ABSTRACT FROM AUTHOR]

In the present research, a new ferrocene‐appended linear donor‐π‐acceptor (D‐π‐A) ester chromophore Fc‐(C6H4)2‐COOC2H5 (2) was synthesized and characterized using various spectroscopic techniques. The molecular structure of chromophore 2 was determined using single‐crystal X‐ray diffraction analysis, revealing its crystallization in the monoclinic crystal system with the P21/n space group. The chromophore Fc‐C6H4‐COOC2H4 (1) was utilized to compare its photophysical and nonlinear optical characteristics with those of 2. Cyclic voltammetry revealed a single‐electron transfer mechanism from Fe2+↔Fe3+. The emission solvatochromism studies show a polarized excited state in response to increasing solvent polarity, indicating charge transfer processes. Interestingly, in mixed aqueous media (THF/H2O), the chromophores exhibit intensified fluorescence due to restricted intra‐molecular rotation (RIR), despite weak emission in THF solvent. Chromophore 2 demonstrated 1.5 times higher second harmonic generation (SHG) efficiency than 1, attributed to its extended π‐conjugation from an additional phenyl ring and reduced antiparallel alignments. Despite its centrosymmetric crystal packing, chromophore 2 exhibited SHG efficiency due to non‐covalent interactions (C−H⋅⋅⋅π) in the crystal lattice. Density Functional Theory (DFT) calculations, employing various functionals, provided insights into dipole moment and first hyperpolarizability, with B3LYP‐hybrid functional underestimating hyperpolarizability values owing to long‐range charge transfer interactions within the D‐π‐A systems, aligning closely with experimental findings. [ABSTRACT FROM AUTHOR]

Herein, this work presents the preparation and characterization of a di-iron toluene-3,4-dithiolate complex with monosubstituted 1,1′-bis(diphenylphosphino)ferrocene (dppf). The reaction of complex [Fe2(CO)6{μ-SC6H3(CH3)S}] (1) with dppf in refluxing toluene gave the monosubstituted analog [Fe2(CO)5(κ1-dppf){μ-SC6H3(CH3)S}] (2) in 50% yield. Complex 2 was identified by elemental analysis, spectroscopies including FT-IR, 1H, 31P{1H}, 13C{1H} NMR and single crystal X-ray diffraction analysis. Moreover, cyclic voltammetry revealed that complex 2 can reduce the protons to dihydrogen in the presence of an acetic acid as a proton source under the electrochemical conditions. [ABSTRACT FROM AUTHOR]

This article explores the use of iron catalysts in the production of urethanes, which are widely used in organic synthesis and medicinal chemistry. The traditional method of producing urethanes involves hazardous chemicals, so researchers have been investigating alternative routes. The article discusses a new method that uses iron catalysts in a photochemical process to convert oxamic acids into isocyanates, which can then react with alcohols to form urethanes. This method shows promise in providing a safer and more environmentally friendly approach to synthesizing urethanes. Additionally, the article discusses the application of graph theory in various fields, such as social networks, biology, and transportation. It explains how graphs can be used to represent and analyze complex systems, allowing researchers to gain insights and make predictions. The authors highlight the importance of graph theory in understanding the interconnectedness of different elements in a system and its potential for future research and applications. [Extracted from the article]

In this study, we report a catalyst‐free aminohalogenation process applied to vinylferrocene, employing N‐halosuccinimides (NXS; X=Cl, Br, I) as dual nitrogen and halogen sources. This 1,2‐diheterofunctionalization reaction takes place with complete regioselectivity, wherein the terminal carbon atom of the vinyl group selectively reacts with the electrophilic halogenating reagent, resulting in the formation of a cationic intermediate, which is subsequently captured by the succinimide anion. The structure of the key cationic intermediate was studied using theoretical methods. This intermediate can react with alternative nucleophiles, enabling a three‐component strategy for the synthesis of novel 1,2‐diheterofunctionalized ferrocene derivatives. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The reaction of ferrocene-containing alkenes and alkynes with HSi(OEt)3 and HSiMe(OMe)2 in the presence of Karstedt catalyst (Pt2[(Me2SiCH=CH2)2O]3) was studied. It was found that only terminal alkenes underwent hydrosilylation, while alkynes entered this reaction even in the case of a disubstituted C≡C bond. The synthesized silicon-containing ferrocene derivatives were used as precursors for the preparation of siloxane aerogels, which were characterized by low-temperature nitrogen adsorption, scanning electron microscopy, and Mössbauer spectroscopy. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The use of an appropriate preparation route is the key to immobilize active molecules into a host matrix with high loadings and stability. Herein, we demonstrate a simple and general strategy to immobilize ferrocene and its derivatives into ZIF-8 with high loadings of up to 4.3% Fe content. The unique host pore structure allows for the stabilization of guest molecules and effectively prevents their leaching. As a result, the obtained electrocatalysts exhibit competitive oxygen evolution reaction (OER) catalytic performance. Optimized Fc-CHO/ZIF-8 requires only a low overpotential of 238 mV to achieve 10 mA cm−2, along with a relatively small Tafel slope of 44.4 mV dec−1. This performance is superior to that of commercial IrO2, suggesting its potential application in electrochemical energy conversion. [ABSTRACT FROM AUTHOR]

Poor immunogenicity seriously hampers the broader implementation of antitumor immunotherapy. Enhanced immunogenicity capable of achieving greater antitumor immunity is urgently required. Here, a novel polymer that contains hydrophobic ferrocene (Fc) units and thioketal bonds in the main chain, which further delivered a prodrug of oxaliplatin and artesunate, i.e., Artoxplatin, to cancer cells is described. This polymer with Fc units in the nanoparticle can work as a polyigniter to spark the peroxide bonds in Artoxplatin and generate abundant reactive oxygen species (ROS) to kill cancers as nanobombig for cancer therapy. Moreover, ROS can trigger the breakdown of thioketal bonds in the polymer, resulting in the biodegradation of the polymer. Importantly, nanobombig can facilitate the maturation of dendritic cells and promote the activation of antitumor immunity, through the enhanced immunogenic cell death effect by ROS generated in situ. Furthermore, metabolomics analysis reveals a decrease in glutamine in nanobombig‐treated cancer cells, resulting in the upregulation of programmed death ligand 1 (PD‐L1). Consequently, it is further demonstrated enhanced tumor inhibitory effects when using nanobombig combined with anti‐PD‐L1 therapy. Overall, the nanosystem offers a rational design of an efficient chemo‐immunotherapy regimen to promote antitumor immunity by improving tumor immunogenicity, addressing the key challenges cancer immunotherapy faced. [ABSTRACT FROM AUTHOR]

This article provides an overview of the synthesis and applications of planar chiral ferrocene derivatives. It discusses two main approaches to introducing planar chirality in ferrocene compounds: base-mediated ortho-metallation and transition-metal-catalyzed C-H bond activations. These methods allow for the introduction of various functional groups and have applications in asymmetric catalysis, medicinal chemistry, and materials science. The authors, Tomáš Čarný and Radovan Šebesta, are experts in organic chemistry and have conducted research in the field of ferrocene derivatives. [Extracted from the article]

A phosphine, base and additive free cross-coupling of arylboronic acid is reported via C–O bond cleavage of acetic anhydride using a switchable ferrocene functionalized n-heterocyclic carbene (NHC) palladium complex. The novel redox active catalytic system afforded the corresponding arylketones with good to excellent yields. [ABSTRACT FROM AUTHOR]

Ferrocenyl derivatives and organometallic iridium(III) complexes have been prospective substitutes for platinum-based anticancer drugs. Eight half-sandwich iridium(III) ferrocene-thiosemicarbazide (Fc-TSC) Schiff base anticancer complexes were prepared in this study. These complexes displayed a dimeric structure and exhibited a particular fluorescence due to the "enol" orientation of the TSC pro-ligand. An energy-dependent pathway of the uptake mechanism was ascertained, which ended in the lysosome and led to lysosome damage and apoptosis. Flow cytometry confirmed that the complexes could block the cell cycle (G1 phase) and improve the levels of intracellular reactive oxygen species, indicating an anticancer mechanism of oxidation. Then, a lysosomal–mitochondrial anticancer pathway was verified through western blotting. In vivo toxicity assays confirmed that these complexes showed better anti-migration ability and less toxicity in comparison to cisplatin. Thus, these complexes provide a new strategy for the design of non-platinum organometallic anticancer drugs. [ABSTRACT FROM AUTHOR]

Two new bis-ferrocene (Fc) conjugated Y-shaped imidazole (IM) based donor–π–acceptor [(D–π)2–IM–π–A] type "push–pull" compounds [(Fc–CH＝CH)2–IM–C8H17–C6H4–R] {R = COOC2H5 (1); COOH (2)} have been synthesized for second-order nonlinear optics (1, ester) and dye-sensitized solar cell (2, acid) applications. The redox potentials of the compounds were examined using cyclic voltammetry, which shows one-electron charge transfer from the ferrocene to ferrocenium ion (Fe2+ Fe3+), and these potentials were employed to calculate the related energy gap. The second-order nonlinear optical (NLO) properties of the ester compound 1 were explored using the Electric-Field-Induced Second Harmonic generation (EFISH) technique in CHCl3 solution with an incident wavelength of 1907 nm, and it shows an interesting μβEFISH value of −780 × 10−48 esu. Besides, the carboxylic acid compound 2, adequately functionalized for anchoring to TiO2, was tested as a photosensitizer in dye-sensitized solar cells (DSSCs) with non-corrosive Cu(I)/Cu(II) complexes as the redox mediator. Although the photovoltaic performance of 2 attached to TiO2 in a DSSC device is rather limited (JSC = 1.51 mA cm−2, VOC = 404 mV, FF = 42.7, η = 0.26%), it confirms the potential of ferrocenyl conjugated D–π–A systems as photosensitizers. In addition, frontier molecular orbital levels, ground and excited state dipole moments (μg and μe), and the origin of electronic absorption spectra were studied by using density functional theory (DFT) with the B3LYP method using 6-31+G** as the basis set. [ABSTRACT FROM AUTHOR]

An effective synthetic protocol towards the oxidation of sumanene–ferrocene conjugates bearing one to four ferrocene moieties has been established. The oxidation protocol was based on the transformation of FeII from ferrocene to FeIII-containing ferrocenium cations by means of the treatment of the title organometallic buckybowls with a mild oxidant. Successful isolation of these ferrocenium-tethered sumanene derivatives 5–7 gave rise to the biological evaluation of the first, buckybowl-based anticancer agents, as elucidated by in vitro assays with human breast adenocarcinoma cells (MDA-MB-231) and embryotoxicity trials in zebrafish embryos supported with in silico toxicology studies. The designed ferrocenium-tethered sumanene derivatives featured attractive properties in terms of their use in cancer treatments in humans. The tetra-ferrocenium sumanene derivative 7 featured especially beneficial biological features, elucidated by low (<40% for 10 μM) viabilities of MDA-MB-231 cancer cells together with a 1.4–1.7-fold higher viability of normal cells (human mammary fibroblasts, HMF) for respective concentrations. Compound 7 featured significant cytotoxicity against cancer cells thanks to the presence of sumanene and ferrocenium moieties; the latter motif also provided the selectivity of anticancer action. The biological properties of 7 were also improved in comparison with those of native building blocks, which suggested the effects of the presence of the sumanene skeleton towards the anticancer action of this molecule. Ferrocenium-tethered sumanene derivatives exhibited potential towards the generation of reactive oxygen species (ROS), responsible for biological damage to the cancer cells, with the most efficient generation of the tetra-ferrocenium sumanene derivative 7. Derivative 7 also did not show any embryotoxicity in zebrafish embryos at the tested concentrations, which supports its potential as an effective and cancer-specific anticancer agent. In silico computational analysis also showed no chromosomal aberrations and no mutation with AMES tests for the compound 7 tested with and without microsomal rat liver fractions, which supports its further use as a potent drug candidate in detailed anticancer studies. [ABSTRACT FROM AUTHOR]

Supercapattery has drawn attention due to its superior tip-discharge efficiency and high energy density without affecting the cycle stability compared to conventional batteries and supercapacitors (SCs). Redox-active porous organic polymers (POPs) are regarded as promising energy storage materials due to the presence of overlapped π-electron clouds between the stacked layers, conjugated backbone, and high-rate charge transfer channels. However, single POPs material has fewer electroactive sites resulting from the broad and ordered π-π stacking in the network structure, limiting their corresponding electrochemical performance. In the present paper, Schiff base polymers containing ferrocene (Fc) and carbon nanotubes (CNTs) were prepared by one pot synthesis method for high-performance supercapattery. The microstructure studies exhibit that the CNTs were combined with the amorphous Schiff base polymer backbone. Moreover, the charge storage mechanism was discussed in detail. The electrochemical properties studies present that the sample (SPOP-Fc0.4/CNTs-5) possess the maximal specific capacitance (201.3 mAh g−1) at 0.5 A g−1 and the excellent specific capacity retention (retaining 84.3% of initial capacitance after 5000 GCD cycles at the current density of 10 A g−1). The enhanced performance shown by SPOP-Fc0.4/CNTs-5 was attributed to the synergy produced by the redox behavior and conjugated backbone provided by SPOP, the doping of Fc, and high-speed ion transport channels provided by CNTs. To evaluate the practicability of electrode materials, the asymmetric supercapattery devices (ASC) were assembled in a configuration of the SPOP-Fc0.4/CNTs-5//activated carbon (AC). SPOP-Fc0.4/CNTs-5//AC delivered a superb energy density of 65.9 Wh kg−1 with a power density of 344.8 W kg−1 while remaining almost 73.6% of the specific capacitance even after 5000 continuous GCD cycles. These Schiff-based POPs with advanced electrochemical capabilities deliver a fresh solution for material selection in energy storage, present extensively apply prospects in energy storage field. [ABSTRACT FROM AUTHOR]

Despite substantial advancements in thermal and photochemical catalysis, the evolution of similar processes within the realm of organic electrochemistry has seen a slower pace. However, recent years have heralded a remarkable surge in molecular electrocatalysis. This innovative technique harnesses the power of molecular catalysts to expedite electrochemical transformations. This article underscores the application of ferrocene (Fc) as a redox catalyst in organic electrosynthesis. It delves into the extensive utilization of Fc in organic electrosynthesis, particularly emphasizing its role in the electrocatalytic generation and reactions of heteroatom‐ and carbon‐centered radicals, among various other reactions. [ABSTRACT FROM AUTHOR]

We report a one-step and efficient method to synthesize magnetic diesel particles (MDPs) and their application toward dye removal. The MDPs were obtained by the combustion of ferrocene-doped diesel fuel using an internal combustion engine. The diesel particles combined with ferrocene as a metal source were collected by an electrostatic precipitator. The thermogravimetric analysis confirmed the ferrocene-based catalyst and thermal stability of MDPs. FE-SEM showed irregular and aggregated morphologies, and the presence of iron oxide phases (Fe4O3 and γ-Fe2O3) was confirmed by X-ray diffraction analysis. The characteristics of MDPs as an adsorbent for organic pollutants were evaluated by methylene blue (MB) adsorption experiments. Langmuir isotherm and pseudo-second-order models best interpret the adsorption process and kinetics, respectively, with a maximum adsorption capacity of 40.81mg/g of MB adsorbed on the surface of magnetic diesel particles. [ABSTRACT FROM AUTHOR]

The electron‐transport layer (ETL) is essential for achieving high performance and stability of organic solar cells (OSCs). However, most organic ETLs suffer from low conductivity, low electron mobility, and difficult modification, resulting in mitigation of charge collection and transport. Metal–organic complex, such as ferrocene, is a promising candidate to improve organic ETL due to their excellent film‐forming property, easy preparation, and high electrical properties. Herein, a small molecule, PDIN‐Fc, based on PDIN modified by ferrocene is designed, which can be synthesized by environmentally friendly esterification and quaternization reactions. PDIN‐Fc displays outstanding alcohol solubility and tunable work function. Interestingly, introducing the ferrocene group can lead to increased self‐doping of PDIN‐Fc. As a result, PDIN‐Fc shows significantly improved charge transport performance and conductivity compared to PDIN. When using PM6:L8‐BO as the photoactive layer, the OSCs with PDIN‐Fc as ETL achieve a remarkable power conversion efficiency of 18.45% and exhibit notable high light stability. This study demonstrates an effective strategy to design efficient ETLs by incorporating metal complexes, which enable thickness insensitivity, good stability, and high‐performance photovoltaic devices. [ABSTRACT FROM AUTHOR]

Microwave technology is commonly used in many fields such as wireless communication and medical treatment, which are closely related to social development. However, electromagnetic pollution caused by microwaves is gradually increasing and the demand for high-performance microwave absorption materials is also increasing. Porous materials obtained by the pyrolysis of metal–organic frameworks (MOFs) at high temperatures exhibit good conductivity and magnetism, and the original skeleton structure of MOFs can be maintained; thus, MOF-derived materials can be considered viable candidates of microwave absorption materials. In this paper, Fe-CN@CoCN materials were prepared by pyrolyzing a ferrocene (Fc)-doped core–shell zeolite imidazole framework (Fc-ZIF-8@ZIF-67) at 700, 800, and 900 °C for 2 h in an Ar atmosphere. The obtained Fe-CN@CoCN-0.25-700 nanocomposite exhibited excellent microwave absorption (MA) performance with a minimum reflection loss (RLmin) of −42.27 dB at 5.68 GHz and an effective absorption bandwidth (EAB, RL < −10 dB) of 4.80 GHz at a thickness of 2.5 mm. The Fe-CN@CoCN-0.25-800 nanocomposite possessed optimized MA properties with an RLmin of −40.78 dB at 12.56 GHz and an EAB of 4.16 GHz at relatively low thickness of 2 mm. Fe-CN@CoCN nanocomposites are expected to be efficient materials for microwave absorption coatings. [ABSTRACT FROM AUTHOR]

Further improvement of the performance and stability of inverted perovskite solar cells (PSCs) is necessary for commercialization. Here, ferrocene derivative dibenzoylferrocene (DBzFe) is used as an additive to enhance the performance and stability of MA‐ and Br‐ free PSCs. The results show that the introduction of DBzFe not only passivates the defects in the film but also inhibits the ion migration in the film. The final device achieves a power conversion efficiency (PCE) of 23.53%, which is one of the highest efficiencies currently based on self‐assembled monolayers (SAMs). Moreover, it maintains more than 96.4% of the original efficiency when running continuously for 400 h at the maximum power point. [ABSTRACT FROM AUTHOR]

Polymeric materials have been widely researched and used as active‐layers to fabricate data‐storage resistance random‐access memory (ReRAM) devices. Nevertheless, the problems as drift voltage, weak stability, and low reproducibility largely restrict their practical application in next‐generation memory systems, mainly induced by the molecular stacking defects that limited the efficient charge‐carrier migration throughout the active‐layers. Thus, how to weaken the molecular stacking defects and thus improve the overall ReRAM performance is a scientific issue that needs to be solved urgently. In this work, an organometallic polymer 5,12‐di(thiophen‐2‐l)‐2,9‐di(tridecan‐7‐yl)anthra[2,1,9‐def:6,5,10‐d'e'f']diisoquinoline‐1,3,8,10(2H,9H)‐tetraone P(DTPDI‐Fc) is designed with ferrocene (Fc) and perylenediimide (PDI) building repeats. The X‐ray diffraction (XRD) test confirms the regioregular stacking styles of P(DTPDI‐Fc) in solid states, and atomic force microscope (AFM) measurement verified the continuous and smooth surface morphology of P(DTPDI‐Fc) films. Therefore, the charge carriers can easily inject into P(DTPDI‐Fc) film and can efficiently migrate throughout P(DTPDI‐Fc) films. Thus, P(DTPDI‐Fc) devices show excellent memory behaviors with low high‐conductance state ON‐state current, stable threshold voltage, long‐time stability, and high device reproducibility. This work affords a practical strategy to weaken molecular stacking defects and to improve stacking regioregularity, which will give a guidance for the designing of multilevel data‐storage ReRAM devices in future researches. [ABSTRACT FROM AUTHOR]

Ferrocene (Fc), a classical organometallic complex, has found potential applications in ligand design, catalysis, and analytical, biological, medicinal and materials chemistry. In recent years, the use of Fc as a building block in supramolecular chemistry has emerged. The molecular shape, size, and hydrophobicity of Fc make it an ideal guest for a variety of macrocyclic host molecules to form stable host–guest complexes. The vertical distance (3.3 Å) between two cyclopentadienyl rings and molecular "ball bearing" property in Fc support the formation of intramolecular π–π stacking, H-bonding and metallophilic interactions between two appropriate substituents in 1,n′-disubstituted ferrocenes. Along with these molecular features, the rigidity along with rotational flexibility, redox reversibility and oxidation-triggered tunable hydrophobicity of Fc have led to its use as an exotic building block for the development of a wide range of supramolecular assemblies such as smart molecular receptors, intricate metal–organic assemblies, supramolecular polymers, and gels including out-of-equilibrium assemblies and metal nanoparticle assemblies. This review highlights the concepts behind the design and development of these assemblies, where the Fc unit has a direct and defined role in their formation and function. The use of Fc in supramolecular assembly is still a relatively young field and set to be the subject of increasing research interest towards the development of fascinating supramolecular structures with tailored properties and programmable functions towards applications in materials and biological sciences. [ABSTRACT FROM AUTHOR]

Hierarchical combinations involving metal–ligand interactions and host−guest interactions can consolidate building blocks with unique functions into material properties. This study reports the construction and hierarchical self‐assembly of multifunctional trinuclear AuI tricarbene complex containing three crown ether units and three ferrocene units. Host−guest interactions between the multifunctional trinuclear AuI tricarbene complex and organic ammonium salts were investigated, revealing that crown ether‐based host−guest interactions can effectively regulate the electrochemical properties of the complex. Utilizing bisammonium salt as the cross‐linker and multifunctional trinuclear AuI tricarbene complex as the core, a stimuli‐responsive and self‐healing supramolecular gel with different functional units was obtained. [ABSTRACT FROM AUTHOR]

New tertiary ferrocenyl stibines (I and III) and bismuthine (II) have been synthesized. All these compounds have been characterized by IR, MS, and NMR spectroscopy and the molecular structures of I–III have been determined by X-ray crystallography. Compounds I–III have also been studied by cyclic voltammetry (CV). Crystal structures of homoleptic stibine and bismuthine (I, II) adopt a "propeller" configuration with the three ferrocenyl groups tilted to minimize interatomic repulsion and exhibit helicoidal chirality. The structures of I and III show that both the stibines exhibit an intramolecular C−H···C interaction. The voltammograms of stibines show that E1/2 values are more positive than that of ferrocene indicating that oxidation of Fc3Sb is slightly more challenging in comparison to ferrocene. Triferrocenyl bismuthine (II) displays two redox waves with low resolution and a non-reversible process. [ABSTRACT FROM AUTHOR]

Based on derivatization of commercial poly(ethylene‐co‐vinyl acetate) (EVA), novel macromolecular UV‐absorbers with polyethylene (PE) backbones and ferrocene side groups are presented in this study. The structures and properties of the polymers were analyzed using various techniques including Fourier transform infrared spectroscopy (FT‐IR), proton nuclear magnetic resonance (1H NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscope (SEM), and UV visible absorption spectroscopy. UV analysis experiments have shown that PE‐grafted ferrocenyl ester (PE‐g‐FE) and PE‐grafted azacyclo‐ferrocene (PE‐g‐AF) with ferrocene side groups have the potential to act as UV absorbers. By using the polymers as additives for commercial PE, the anti‐migration experiment demonstrates that PE‐g‐AF, with a heterocyclic structure, exhibits superior anti‐migration performance than the ester‐linked PE‐g‐FE. Furthermore, in comparison to commercial small‐molecular UV absorbers (UV‐329), the PE‐g‐AF absorber not only exhibits better UV absorption performance but also demonstrates almost zero migration behavior within the PE matrix. [ABSTRACT FROM AUTHOR]

An efficient method has been developed for the synthesis of resorcinol–formaldehyde hybrid aerogels with ferrocene subunit fragments embedded in their polymer structure. For gelation preceding the synthesis of aerogels, dioxane was used for the first time as the main reaction solvent. The gels were converted into aerogels using SC-CO2. The aerogel samples were characterized in detail by Mössbauer spectroscopy, nitrogen adsorption, and atomic absorption spectroscopy. The density of the materials was determined. The iron content in the resulting aerogels varies from 1.5 to 11 wt % (or 5.6–36.3 wt % ferrocene units). The metallocene subunits are present in aerogels in two valence-oxidation states: ferrocene and ferrocenium. [ABSTRACT FROM AUTHOR]

The winery industry generates large volumes of wastewater which can be toxic if released to the environment without proper treatment. The aim of this work was to treat two winery wastewaters (from red and white wine production) using Fenton-based processes. With the application of the best operational conditions, namely, pH = 3.0, [ferrocene] = [FeSO4•7H2O] = 0.50 g/L, [H2O2] = 155 mM, temperature = 298 K, and radiation UV (254 nm), to the treatment of a red WW, a chemical oxygen demand (COD) removal of 98.9 and 84.5% for the homogeneous and heterogeneous photo-Fenton processes, respectively, was achieved. The same conditions were applied in the treatment of a white WW and a 98.9 and 84.5% COD removal was achieved. Based on the results, it can be deduced that homogeneous and heterogeneous Fenton-based processes are effective in organic carbon removal, UV-C radiation is essential in hydroxyl radical ( HO • ) generation, and the multiple addition of H2O2 reduces HO • scavenging. Finally, it is concluded that both the homogeneous and heterogeneous photo-Fenton processes are effective for red and white WW treatment. [ABSTRACT FROM AUTHOR]

Acidithiobacillus ferrooxidans are beneficial bacteria for bioleaching in the mining industry to extract useful fractions from tons of waste. These bacteria are able to oxidize ferrous iron (Fe2+) to ferric iron (Fe3+) and use the released energy to assimilate carbon from carbon dioxide or carbonates, and can be used in the desulfurization of coal and gas. In this regard, activators of the growth of these bacteria may be useful. During the experiments on these bacterial strains, an unexpected effect of growth activation was revealed. This gives rise to further research in this direction and the identification of patterns of "structure‐activity" derivatives of ferrocene and porphyrins in relation to A. ferrooxidans. [ABSTRACT FROM AUTHOR]

With both ferrocene and air as the redox catalysts, for the first time, the low-cost natural ilmenite (FeTiO3) was successfully used for photocatalytic bond formations. Under the assistance of a traceless H-bond, and HCHO as the methylene reagent, a variety of imidazo[1,5-a]quinoxalinones were semi-heterogeneously photosynthesized in high yields with good functional group compatibility. [ABSTRACT FROM AUTHOR]

Ferrocene was dissolved in a water‐in‐salt solution containing a high concentration of a supporting electrolyte. Open‐circuit potential, electronic absorption spectra, and cyclic voltammetry revealed that a part of the dissolved ferrocene existed as ferrocenium ions. Spectroelectrochemical measurements and higher‐order derivative spectra revealed that the water‐in‐salt electrolyte aqueous solution is an excellent medium for electrochemical and spectroscopic measurement of redox‐active species with water insolubility. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

To enhance the combustion performance of composite solid propellants (CSPs), a series of ferrocene‐based pyrazole energetic compounds were prepared and characterized systemically by spectroscopic techniques in this study. Moreover, their catalytic performance and mechanism as burning rate catalysts (BRCs) were investigated, and the related kinetic parameters were obtained via Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS) methods, respectively. Besides, their anti‐migration performance and mechanism were studied via simulating the aging experiments of propellant samples at different times. The results showed that these compounds exhibited excellent catalytic effect on the thermal decomposition of ammonium perchlorate, which is a vital oxidizer in CSPs and determines its combustion performance. Among them, EMFc‐1 showed the best catalytic performance because of the higher content of active component. The pyrolysis temperature of ammonium perchlorate was reduced by 56.2 °C and the heat release was increased by 248.2 J g−1 with 5 wt% EMFc‐1 as catalyst. Moreover, their anti‐migration performance was improved greatly compared with the commercial catocene (Cat) and ferrocene. The work indicates that these compounds can be applied as BRCs to enhance the combustion performance of propellants. [ABSTRACT FROM AUTHOR]

Two aliphatic diamine-bridged ferrocene ligands (C2-Fe-Ligand and C6-Fe-Ligand) were synthesized with aliphatic diamine and formylferrocene, and the corresponding bimetallic active site complexes (Ni-C2-Fe, Co-C2-Fe, and Ni-C6-Fe) were prepared to catalyze ethylene oligomerization. The ligands and the corresponding complexes were characterized by FTIR, 1H NMR, TG, ESI-MS, XRD, and SEM. The SEM results of the ligands confirmed that the length of the bridged group had an influence on the morphology, and an increase in the carbon length led to irregular short rods to the irregular flakes with a large size. The bimetallic complexes catalyzed efficiently ethylene oligomerization with MAO as co-catalyst, and these complexes produced C4 and C6 olefins. Ni-C2-Fe showed higher activity of 6.31 × 104 g·(mol Ni·h)−1 in cyclohexane at Al/Ni molar ratio of 700, temperature of 25 °C, and pressure of 0.5 MPa. Compared with single active site catalysts, the bimetallic active site catalysts had a higher selectivity for C4 olefin because of the competitive insertion of ethylene between different active centers. The modification of the metal center tuned the catalytic performance of the complexes in ethylene oligomerization. [ABSTRACT FROM AUTHOR]

Due to increased lipophilicity, stability, and decreased cytotoxicity in biological systems, ferrocene derivatives are promising building blocks for therapeutic agents. This manuscript reports the binding of N'-ferrocenylmethyl-N'-phenylbenzohydrazide (FhD) with deoxyribonucleic acid (DNA) studied by absorption spectroscopy and cyclic voltammetry. Binding constants and binding free energies for the FhD-DNA complex were measured using these two methods as 5100 M−1, 6109 M−1 and −21.2 kJ/mol, −21.6 kJ/mol, respectively. DFT calculations were also performed and revealed important physical characteristics of the FhD compound. Subsequently, the system was explored by computational molecular docking, confirming a non-covalent mode of binding via minor groove with a binding energy of −25.5 kJ/mol. Furthermore, molecular dynamics of the docked complex of FhD with DNA were carried out for 100 ns followed by MM-GBSA to have a deep understanding of the complex's dynamic behavior in physiological systems, and to determine the Gibbs free energy which was −14.31 Kcal/mol over a 100 ns window. The results show important antitumor potential of FhD due to its spontaneous non-covalent interaction with DNA and the efficient binding stability of the FhD-DNA complex in a physiological system. [ABSTRACT FROM AUTHOR]

The first example of intramolecular diastereoselective domino reaction of ferrocene 1,1'-bis-enone to [5]ferrocenophane initiated with sodium ethoxide was found. The product is [5]ferrocenophane with two pyridyl and one ethoxy substituents arranged asymmetrically in a five-carbon bridge. Diffraction studies showed that ferrocene is in almost ideal eclipsed conformation. The fan conformation found in the crystal is also preserved in solution, which was determined by NMR spectroscopy. [ABSTRACT FROM AUTHOR]

A simple and convenient approach to the synthesis of the derivatives of unsymmetrical 1,1′-disubstituted cyclopropane-containing azinylferrocenes was suggested. A regioselective method for the Friedel—Crafts acylation of monoazinyl-substituted ferrocenes with a 4-chlorobutyryl chloride—AlCl3 mixture in CH2Cl2 under an inert atmosphere was elaborated. The acylation product on treatment with ButOK in DMSO readily underwent γ-elimination of HCl to give the corresponding cyclopropanes. The structures of the synthesized compounds were confirmed by IR spectroscopy, 1H and 13C spectroscopy, mass spectrometry, and X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

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Abstract Coordination of a stereochemically defined P3‐chain to a series of transition metal carbonyls [M(CO)x]z− (M = Mn (x = 5, z = 1), Fe (x = 4, z = 2) or Co (x = 4, z = 1)) is explored using a [3]ferrocenophane scaffold. A gradual transition from η1‐, η2‐ to η3‐coordination is observed where in the η2‐mode the terminal positions of the phosphorus chain are bridged. With an excess of cobalt carbonyl successive P–P bond activation and gradual separation of the central phosphorus atoms from the phosphorus chain has been observed. This process is reversible and with suitable reagents such as methyl lithium, the P3‐unit is regenerated in stereospecific manner. The bonding situation and steps of the gradual P–P bond activation are investigated by DFT calculations as well as experimental methods (e.g., NMR spectroscopy, X‐ray crystallography).