Ferrocene Units Research Articles

Enhanced stability in pseudocapacitors: Synthesis and characterization of a novel cathode material incorporating cinnamate and ferrocenyl functional groups

This study reports the synthesis of a novel block copolymer, PEO-PFc-PCA, comprising cinnamic acid and ferrocene units via Atom Transfer Radical Polymerization (ATRP), and its application as a positive electrode material in pseudocapacitors. Ferrocene functions as redox-active sites for energy storage, while cinnamic acid, when crosslinked under UV light, forms a nano-network that reduces ferrocene leaching, thereby enhancing the stability and lifespan of the pseudocapacitors. Comprehensive structural characterization, including nuclear magnetic resonance and UV–visible spectroscopy, was conducted on PEO-PFc-PCA. Electrochemical tests—cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy—revealed that UV crosslinking improved the electrochemical performance, indicated by a slight increase in current and extended charging plateaus. Specific capacitance and energy density increased by 10 % post-crosslinking, demonstrating improved energy storage capacity. Nyquist plots showed reduced internal and charge transfer resistance after crosslinking, enhancing the electrochemical pathway. Stability tests indicated that crosslinked PEO-PFc-PCA retained 90.1 % of its capacitance after 3000 cycles, compared to 86.6 % pre-crosslinking, highlighting its superior longevity. This research presents a promising approach to enhancing pseudocapacitor energy storage through cinnamic acid photopolymerization, potentially benefiting broader pseudocapacitive electrode designs.

Ferrocene-based chemosensor creates molecular logic circuit for selective detection of Hg2+ and Cu2+

A cation sensor, R, with multi-channel signaling was developed by creating a covalent connection between a ferrocene unit and pyridyl-pyrazole rings. Spectroscopic techniques and single-crystal X-ray diffraction were employed to characterize sensor R. The examination revealed a dihedral angle of 140.09° for the pyridyl-pyrazole rings. The receptor R functions as a highly selective multi-channel chemosensor, exhibiting chromogenic, fluorogenic, and electrochemical capabilities. In a CH3CN/water (9:1) solvent mixture, receptor R operates as a multi-channel signaling chemosensor, selectively detecting Hg2+ and Cu2+ ions in water. The original pale-yellow solution turned orange upon Hg2+ addition and green upon Cu2+ addition. A new low energy (LE) band at 460 nm was detected after adding one equivalent of Hg2+. In cyclic voltammetry (CV), the half-wave potential (E1/2) of 462 mV shifted to 622 mV, whereas in differential pulse voltammogram (DPV), the oxidation peak underwent an anodic shift (ΔE1/2 = 155 mV). The maximum emission at 423 nm was lowered by more than 90 % when the concentration of Hg2+ ions reached one equivalent. One equivalent addition of Cu2+ results in a new LE band at 740 nm. Cu2+ ions suppress the oxidation peak current in both the CV and DPV of R. It also demonstrates chelation-enhanced fluorescence effect (CHEF) with Cu2+. The interaction between cations and R was elucidated through 13C NMR titration. DFT calculations revealed the binding mode. Its distinctive fluorescence demonstrates a 'turn-on' response to Cu2+ and a 'turn-off' response to Hg2+ with selectivity. This concept has been applied to create a molecular combinatorial logic circuit.

Redox-gated recognition of dihydrogen phosphate using a ferrocene-tethered non-symmetric aryl-triazole pentad

ABSTRACT Anions play many roles in our environment. Consequently, the development of synthetic receptors capable of targeted anion binding is of ongoing importance. While many such receptors are known, simplified designs and measurement approaches are always beneficial. Herein, we report the synthesis of a non-symmetric aryl-triazole pentad receptor appended with a single ferrocene, its electrochemistry, and the selective binding to dihydrogen phosphate (H2PO4 –) anions of its oxidised form over various environmentally prevalent anions (HSO4 –, Cl–, NO3 –). The receptor was constructed using a modular architecture with simple installation of a ferrocene unit using click chemistry. Electrochemical analysis on the receptor revealed that addition of H2PO4 – anion led to a shift in the redox peaks of the receptor (FcP) towards more negative potentials, indicating higher anion affinity was achieved after the ferrocene was oxidised to its cationic form (FcP + ). This work verifies prior studies on the efficacy of cationic charge in simpler receptor design for the creation of functional host-guest systems.

Late transition metal complexes of ferrocene‐containing nitrogen ligands: Coordination chemistry, electron transfer properties, and tumor cell viability

Bis(2‐picolyl)amine (bpa), iminodiacetamide (imda), and bis‐1,2,3‐triazole (bta) ferrocene ligands (L) with and without an aliphatic linker were prepared by multi‐step synthesis. The cis‐fac, trans‐fac, or mer stereochemistry of their ML2 complexes with Ni(II), Cu(II), Cd(II), and Zn(II) was studied in the solid state (infrared [IR] and single‐crystal X‐ray diffraction [SC‐XRD]), in solution (nuclear magnetic resonance [NMR] and cyclic voltammetry [CV]) and by density functional theory (DFT) calculations. Crystal structures were determined for bpa ligand 7, and complexes [Ni(1)2](NO3)2 (1Ni), [Cu(8)2]OTf2 (8Cu), [Ni(10b)2](NO3)2 (10bNi), and [Cu(10b)2]OTf2 (10bCu). The bond strength of the central metal ion to the ligand amine nitrogen atom was studied by NMR, electrochemistry, and DFT. The information on redox‐active centers, electron transfer properties of ferrocene ligands (L), and their in situ complexation with zinc(II) and nickel(II) ions were obtained by voltammetric analysis. In addition, DFT calculations showed that the electron ionization in ML2 complexes occurs from one of the ferrocene units, leaving the electronic structure of the other ligand intact, while some of the expelled electron density is recovered by the adjacent amine through resonance. This effect is more pronounced in the free ligands, because the eventual amine resonance in ML2 needs to balance its Zn(II) coordination participation, which justifies why they show higher ionization energies over free ligands. Moreover, due to lower steric hindrance, the N(amino)–Zn(II) coordination is additionally stronger in 1:1 ML complexes, which makes their electron depletion further more demanding. If compared with the clinical drug cisplatin, complexes of bpa 1Ni and imda 2Ni showed a better effect on the viability of different tumor cell lines and better selectivity towards normal cells. Treatment with 1Ni and 2Ni causes an increase of cells in the S phase of the cell cycle and leads to the accumulation of cells in G0/G1. A decrease in the expression level of anti‐apoptotic marker Bcl‐2 upon treatment with both compounds together with increased amount of Annexin V‐FITC positive cells implied apoptosis as the mode of cell death.

Treatment of Acute Wound Infections by Degradable Polymer Nanoparticle with a Synergistic Photothermal and Chemodynamic Strategy.

Mild-heat photothermal antibacterial therapy avoids heat-induced damage to normal tissues but causes bacterial tolerance. The use of photothermal therapy in synergy with chemodynamic therapy is expected to address this issue. Herein, two pseudo-conjugated polymers PM123 with photothermal units and PFc with ferrocene (Fc) units are designed to co-assemble with DSPE-mPEG2000 into nanoparticle NPM123/Fc. NPM123/Fc under 1064nm laser irradiation (NPM123/Fc+NIR-II) generates mild heat and additionally more toxic ∙OH from endogenous H2O2, displaying a strong synergistic photothermal and chemodynamic effect. NPM123/Fc+NIR-II gives >90% inhibition rates against MDR ESKAPE pathogens in vitro. Metabolomics analysis unveils that NPM123/Fc+NIR-II induces bacterial metabolic dysregulation including inhibited nucleic acid synthesis, disordered energy metabolism, enhanced oxidative stress, and elevated DNA damage. Further, NPM123/Fc+NIR-II possesses >90% bacteriostatic rates at infected wounds in mice, resulting in almost full recovery of infected wounds. Immunodetection and transcriptomics assays disclose that the therapeutic effect is mainly dependent on the inhibition of inflammatory reactions and the promotion of wound healing. What is more, thioketal bonds in NPM123/Fc are susceptible to ROS, making it degradable with highly favorable biosafety in vitro and in vivo. NPM123/Fc+NIR-II with a unique synergistic antibacterial strategy would be much less prone to select bacterial resistance and represent a promising antibiotics-alternative anti-infective measure.

Role of the Environment Polarity on the Photophysical Properties of Mesogenic Hetero-Polymetallic Complexes.

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.

Ferrocene-Bearing Homoleptic and Heteroleptic Paddlewheel-Type Dirhodium Complexes

Two ferrocenecarboxylate (fca)-bridged dirhodium (Rh2) complexes, [Rh2(fca)4] (1) and [Rh2(fca)(piv)3] (2; piv = pivalate), were prepared through the carboxylate-exchange reactions of [Rh2(O2CCH3)4(H2O)2] and [Rh2(piv)4], respectively, with fcaH and characterized by 1H NMR, ESI-TOF-MS, and elemental analyses. Single-crystal X-ray diffraction analyses of [Rh2(fca)4(MeOH)2] (1(MeOH)2) and [Rh2(fca)(piv)3(MeOH)2] (2(MeOH)2), which are recrystallized from MeOH-containing solutions of 1 and 2, revealed that (1) 1(MeOH)2and 2(MeOH)2possess homoleptic and heteroleptic paddlewheel-type dinuclear structures, respectively; (2) both complexes have a single Rh–Rh bond (2.3771(3) Å for 1(MeOH)2, 2.3712(3) Å for 2(MeOH)2); and (3) the cyclopentadienyl rings of the fca ligands in 1(MeOH)2 adopt an eclipsed conformation, whereas those in 2(MeOH)2 are approximately 12–14° rotated from the staggered conformation. Density functional theory (DFT) calculations revealed that (1) the electronic configurations of the Rh2 core in 1(MeOH)2 and 2(MeOH)2are π4σ2δ2π*2δ*2π*2 and π4σ2δ2δ*2π*4, respectively; and (2) the occupied molecular orbitals (MOs) localized on the fca ligands are energetically degenerate and relatively more unstable than those on the Rh2 cores. Absorption features and electrochemical properties of 1 and 2 were investigated in a 9:1 CHCl3-MeOH solution and compared with those of fcaH and [Rh2(piv)4]. Through examining the obtained results in detail using time-dependent DFT (TDDFT) and unrestricted DFT, we found that 1 and 2 exhibit charge transfer excitations between the fca ligands and Rh2 cores, and 1 shows electronic interactions between ferrocene units through the Rh2 core in the electrochemical oxidation process.

Engineering of Molecular Bridge on Buried Interface via Ferrocene Carboxylic Acid for High Performance Perovskite Light‐Emitting Devices

AbstractQuasi‐two‐dimensional (Quasi2D) perovskite materials gained widespread attention due to whose unique and highly desirable luminescence properties. However, the behavior of perovskite lightemitting diodes (PeLEDs) is prejudiced by inefficient cascading energy transfer of perovskite film and unbalanced charges injection. Here, ferrocene carboxylic acid (FcAd) is employed between hole transport layer (HTL) and perovskite layer as a molecular bridge to solve the current problems of PeLEDs. Ferrocene units can bond with [PbBr6]4−, forming one‐dimensional (1D) intermediate phases of FcPbBr3 at the interface, which can manipulate the growth kinetics of perovskite and reconstruct the phase distribution. Therefore, due to the suppression of low dimensional phase content, not only is the cascaded energy transfer of PEA2(CsPbBr3)2PbBr4 films effectively achieved, but also the quasi‐2D perovskite's work function is reduced. Additionally, Pb2+ coordinated with the carboxyl group of FcAd, inducing an electric dipole effect that leads to an further upward shift of the perovskite energy level. Eventually, the synergy achieves a significant tailoring between the perovskite and HTL energy exhibits the most excellent external quantum efficiency (EQE) exceeds 27% and optimal brightness exceeds 240000 cd m−2. Therefore, the preparation method will provide an effective strategy to widen the color gamut of next‐generation displays.

Ferrocene-chalcone-based probe for the fluorescence and electrochemical dual-mode detection of carboxylesterase

Carboxylesterases (CEs) are widely distributed in the body and catalyze the hydrolysis of endogenous and exogenous substrates. They play important roles in drug metabolism, and abnormal levels often result in numerous diseases such as cancers. Therefore, it is important to establish a highly selective and sensitive probe for the real-time sensing of CEs activity. Herein, we synthesized a novel fluorescence-electrochemical multichannel probe 1 containing a ferrocene unit, which not only serves as part of the structure of probe 1 but also provides electrochemical signals. The probe exhibited high selectivity to CEs with a “Turn-On” fluorescence response and was applied for imaging in complicated biological samples including Staphylococcus aureus, living cells, and zebrafish. Furthermore, the hydrolysis of the acetoxy group of probe 1 by CEs decreased the electrochemical signal. All these results suggest that probe 1 can act as a multi-modal probe for real-time tracking of the activity CEs in complex biological environments.

NIR absorbing ferrocenyl perylenediimide-based donor-acceptor chromophores.

A set of ferrocenyl-functionalized perylenediimide (PDI) compounds and their 1,1,4,4-tetracyanobuta-1,3-diene (TCBD) derivatives 1-5 were designed and synthesized using palladium-catalyzed Sonogashira cross-coupling, followed by a thermally activated [2 + 2] cycloaddition-retroelectrocyclization [CA-RE] reaction with a 1,1,2,2-tetracyanoethylene (TCNE) acceptor in good yields. The TCBD group works as an acceptor, whereas the ferrocenyl group acts as a donor at the central PDI core. The effects of varying the number of ferrocenyl and TCNE groups on the photophysical, thermal, electrochemical, and spectroelectrochemical properties were studied. The di-substituted PDI derivatives 3, 4, and 5 exhibit bathochromic shifts in the absorption spectra compared to 1 and 2, attributed to the extended π-conjugation. The electrochemical analysis of derivatives 2, 4, and 5 shows multiple reduction waves in the low potential region due to the presence of TCBD and perylenediimide acceptor units. Spectroelectrochemical studies were performed, showing that upon applying redox potentials, the absorption spectra shifted from the visible to the near-infrared (NIR) region. Computational calculations indicate that in the HOMO, the electron density is localized on the ferrocene unit, while in the LUMO, it is distributed over the PDI-TCBD unit, indicating a strong D-A interaction.

Synthesis and catalytic properties of palladium(II) complexes with P,π-chelating ferrocene phosphinoallyl ligands and their non-tethered analogues.

Hybrid phosphines usually combine a phosphine moiety with another heteroatom secondary donor group in their structures while compounds equipped with hydrocarbyl π-donor moieties remain uncommon. This contribution reports the synthesis and structural characterization of the first P/π-allyl-chelating complexes that were obtained using the structurally flexible and redox-active ferrocene unit as the scaffold, viz. [PdCl(R2PfcCHCHCH2-η3:κP)] (1R; R = Ph and cyclohexyl (Cy); fc = ferrocene-1,1'-diyl). These compounds were synthesized from the respective phosphinoferrocene carboxaldehydes R2PfcCHO via reaction with vinylmagnesium bromide to generate 1-(phosphinoferrocenyl)allyl alcohols, which were subsequently acetylated. The resulting allyl acetates reacted smoothly with [Pd2(dba)3]/[Et3NH]Cl (dba = dibenzylideneacetone) to produce the target compounds. Complexes 1R and their nontethered analogues [PdCl(η3-C3H5)(FcPR2-κP)] (5R; Fc = ferrocenyl) were evaluated as pre-catalysts for the Pd-catalysed allylic amination of cinnamyl acetate with aliphatic amines and Suzuki-Miyaura-type cross-coupling of 4-tolylboronic acid with benzoyl chloride. In these reactions, better results were achieved with compounds 5R (particularly with 5Ph), presumably because they form more stable LPd(0)-type catalysts.

Ligand-engineered Ni-based metal–organic frameworks for electrochemical oxygen evolution reaction

Regulating morphology and crystal structure of metal–organic frameworks (MOFs), as well as fabricating bimetallic MOFs have been widely proposed to optimize the electronic structure of MOFs and thus enhance electrochemical oxygen evolution reaction (OER) activity. Distinguish from these conventional and complex strategies, this work mainly focuses on the convenient ligand-engineering strategy to optimize the electronic structure of Ni-MOFs. Specifically, the electron-rich ferrocene (Fc) unit is linked into the ligand of Ni-MIL-53-NH2 by the stable covalent bond on the basis of Schiff-base reaction. Noticeably, the resulting Ni-MIL-53-Fc exhibits significantly enhanced OER activity compared to parent Ni-MIL-53-NH2, achieving 6.6-times improvement of TOF value from 0.19 to 1.25 s−1 at the overpotential of 350 mV. Further characterizations confirm that the incorporation of Fc unit can enhance the charge transfer, which induces more electrons aggregated in the Ni active sites and thus improves the intrinsic activity of Ni sites toward OER activity. This ligand-engineering strategy can be extended to fabricate highly active and stable catalysts toward other electrocatalytic reactions.

Construction and Hierarchical Self-Assembly of a Supramolecular Metal-Carbene Complex with Multifunctional Units.

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.

Tailored multi-functional molecular chain-based ferrocene derivative for efficient and stable perovskite solar cells

Under the stimulation of external factors, the ions with small activation energies could escape from the surface of perovskite, aggravating the defects at the interfaces and deteriorating the perovskite solar cells (PSCs). Here, we report a novel strategy utilizing a tailored organometallic molecule (bis-ferrocenyl-carboxylate-hexadecafluorodecyl, namely Fc-16 F) interlayer to functionalize the perovskite/hole transport layer interface, which simultaneously blocks the migration pathways of ions and facilitate the charge extraction at the interface. The electron-absorbing substituents (carboxyl groups and a long C-F chain) are introduced to strengthen the redox properties of ferrocene units, limit self-migration, and enhance hydrophobicity. With the strengthened oxidation driving force and the tight and dense hydrogen bond networks formed between Fc-16 F and organic cations, Fc-16 F could efficiently recover the Pb, I vacancies, inhibit the diffusion of defect-induced by-products (I2), and stabilize the components on the surface. The champion device modified with Fc-16 F interlayer yields a remarkable power conversion efficiency (PCE) of 23.02% as well as superior humidity and long-term stabilities. The Fc-16 F-modified PSCs retain an outstanding 83.3% of its initial PCE over 1200 h under high humidity (60% RH) and retain over 90% of its initial PCE after aging in the N2 atmosphere for over 2000 h.

Conjugate ferrocene polymer derived magnetic Fe/C nanocomposites for electromagnetic absorption application

Coordination bonds are relatively unstable compared to covalent bonds, and common carbon-based absorbing material precursors are bonded in the form of coordination bonds. In this work, we have introduced ferrocene units into conjugated microporous polymers (CMP) in one step by Suzuki reaction. By adjusting the proportion of ferrocene units, a series of magnetic Fe-C nanocomposites (Fe-P-XC) derived from conjugated ferrocene polymers without heteroatom doping (N, S, P, etc.) were formed. The Fe-P-2C composite has good absorption properties with minimum reflection loss at 4.4 GHz (-58.66 dB) and effective absorption bandwidth (EAB) of 6.28 GHz at 2.4 mm (11.72–18 GHz). Compared with the precursor materials formed by coordination bonds, the present work reveals the electromagnetic wave absorption mechanism of carbon-based materials without heteroatom doping through a simple and effective strategy.

A Combined Plasmonic and Electrochemical Aptasensor Based on Gold Nanopit Arrays for the Detection of Human Serum Albumin.

Electrochemical and optical platforms are commonly employed in designing biosensors. However, one signal readout can easily lead to inaccuracies due to the effect of nonstandard test procedures, different operators, and experimental environments. We have developed a dual-signal protocol that combined two transducer principles in one aptamer-based biosensor by simultaneously performing electrochemical- and extraordinary optical transmission (EOT)-based plasmonic detection using gold nanopit arrays (AuNpA). Compared with full hole structures, we found that nanopits, that did not fully penetrate the gold film, not only exhibited a better plasmonic bandwidth and refractive index sensitivity both in the finite-difference time-domain simulation and in experiments by shielding the gold/quartz mode but also enlarged the electrochemical active surface area. Therefore, the periodic non-fully penetrating AuNpA were modified with ferrocene-labeled human serum albumin aptamer receptors. The formation of the receptor layer and human serum albumin binding complex induced a conformational change, which resulted in variation in the electron transfer between the electro-active ferrocene units and the AuNpA surface. Simultaneously, the binding event caused a surface plasmon polaritons wavelength shift corresponding to a change in the surface refractive index. Interestingly, although both transducers recorded the same binding process, they led to different limits of detection, dynamic ranges, and sensitivities. The electrochemical transducer showed a dynamic detection range from 1 nM to 600 μM, while the optical transducer covered high concentrations from 100 μM to 600 μM. This study not only provides new insights into the design of plasmonic nanostructures but also potentially opens an exciting avenue for dual-signal disease diagnosis and point-of-care testing applications.

Catalytic combustion of a dendrimer containing ferrocene units with anti‐migration performance on composite propellant

Ferrocene‐based compounds are promising burning rate catalysts due to their attractive catalytic activity, flammability, and non‐toxic performance. Unfortunately, the high‐migration issue of the ferrocene‐based catalysts makes it challenging to store composite solid propellants for a long time. Therefore, a dendrimer containing ferrocene units with anti‐migration ability was designed herein. The introduction of polar groups provides a large number of interaction sites for anti‐migration, and no migration of the dendrimer in the propellant was observed after 4 weeks of the aging test. For catalytic performance, the results showed that the thermal decomposition temperature of ammonium perchlorate could be reduced from 404°C to 369°C by adding 3 wt% ferrocene‐based dendrimer. Moreover, compared with the propellant mixed with Catocene, the propellant containing ferrocene‐based dendrimer showed a lower pressure exponent (0.47) and a higher burning rate (2.03 mm·s−1, at 0.1 MPa).

Utility of a Ferrocene Unit in a Cyclometallated Cp*Ir(III) Catalyst during Water Oxidation: Exploring Bimetallic Cooperativity

AbstractFerrocene functionalized 2‐phenylpyridine iridium(III) pentamethylcyclopentadienyl complex is synthesized and probed for oxygen evolution from water. The excellent activity of this system has been rationalized by proposing a Fe(III)/Ir(IV) transient intermediate where bimetallic redox synergism between the Fe and Ir centres possibly provide an alternative pathway rather than a conventional Ir(V) based cycle.

Strategic Design and Synthesis of Ferrocene Linked Porous Organic Frameworks toward Tunable CO2 Capture and Energy Storage.

This work focuses on porous organic polymers (POPs), which have gained significant global attention for their potential in energy storage and carbon dioxide (CO2) capture. The study introduces the development of two novel porous organic polymers, namely FEC-Mel and FEC-PBDT POPs, constructed using a simple method based on the ferrocene unit (FEC) combined with melamine (Mel) and 6,6'-(1,4-phenylene)bis(1,3,5-triazine-2,4-diamine) (PBDT). The synthesis involved the condensation reaction between ferrocenecarboxaldehyde monomer (FEC-CHO) and the respective aryl amines. Several analytical methods were employed to investigate the physical characteristics, chemical structure, morphology, and potential applications of these porous materials. Through thermogravimetric analysis (TGA), it was observed that both FEC-Mel and FEC-PBDT POPs exhibited exceptional thermal stability. FEC-Mel POP displayed a higher surface area and porosity, measuring 556 m2 g-1 and 1.26 cm3 g-1, respectively. These FEC-POPs possess large surface areas, making them promising materials for applications such as supercapacitor (SC) electrodes and gas adsorption. With 82 F g-1 of specific capacitance at 0.5 A g-1, the FEC-PBDT POP electrode has exceptional electrochemical characteristics. In addition, the FEC-Mel POP showed remarkable CO2 absorption capabilities, with 1.34 and 1.75 mmol g-1 (determined at 298 and 273 K; respectively). The potential of the FEC-POPs created in this work for CO2 capacity and electrical testing are highlighted by these results.

A Redox‐Responsive Ferrocene‐Based Capsule Displaying Unusual Encapsulation‐Induced Charge‐Transfer Interactions

AbstractA ferrocene‐based capsule is spontaneously and quantitatively formed in water by the assembly of bent amphiphiles carrying two ferrocene units. The disassembly and assembly of the new organometallic capsule, with a well‐defined and highly condensed ferrocene core, are demonstrated by chemical redox stimuli in a fully reversible fashion under ambient conditions. In contrast to previously reported multiferrocene assemblies, only the present capsule efficiently encapsulates typical organic/inorganic dyes as well as electron‐accepting molecules in water. As a result, unusual host‐guest charge‐transfer (CT) interactions, displaying relatively wide absorption bands in the visible to near‐infrared region (λ=650–1350 nm), are observed upon the encapsulation of acceptors (i.e., chloranil and TCNQ). The resultant encapsulation‐induced CT interactions can be released by a redox stimulus through the disassembly of the capsule.