Anion Exchange Reaction Research Articles

All‐Optical Imaging Using Perovskite Nanocrystals Based on Spectro‐Spatial Correlation

AbstractThe exponential growth of data from sensors and internet‐connected devices has challenged traditional electronic computing, particularly in processing speed and power efficiency. Optical information processing, with its inherent high speed and parallelism, offers a promising solution. Moreover, optical processing is vital for developing all‐optical networks, where all‐optical imaging is essential. In this paper, a novel all‐optical imaging technique that leverages in situ anion exchange reactions between perovskite nanocrystals to create an array of pixels with tunable emission wavelengths is proposed. This method enables the conversion of UV light, whether transmitted or reflected by an object, into the visible spectrum, thereby establishing a direct correlation between spectral and spatial information. By employing wavelength division multiplexing (WDM), the approach reduces the dimensionality of information acquisition from two dimensions to one, enhancing imaging speed. This innovation paves the way for significant advancements in all‐optical imaging and image processing, offering new possibilities for faster and more efficient imaging technologies.

Revealing Anion Exchange in Two-Dimensional Nanocrystals.

Ion exchange is a powerful postsynthesis tool for the design of functional nanomaterials. However, achieving anion exchange while maintaining the original morphology and crystal structure, as well as elucidating the mechanism, remains challenging. Here, we developed an anion-exchange strategy under mild conditions and revealed an unusual ion-exchange mechanism in the semiconductor nanoplatelets. Kinetic studies have demonstrated that the transformation follows first-order kinetics, with the ligand restricting the guest anion from diffusing only in one-dimensional directions. By monitoring the reaction process, we demonstrated that the anion exchange reaction occurs selectively on the polar surface of the NPLs and exhibits asymmetry at the two polar end faces. Theoretical simulations further confirmed that anion exchange began from the chalcogenide-dominated facet. The thermodynamic data suggest that guest ions diffuse into the crystal interior via a direct exchange mechanism. This study provides a pathway for anion exchange and the construction of functional nanocrystals and a platform for studying the optoelectronic behavior of single-sheet heterojunctions.

Anion Exchange and Lateral Heterostructure Formation in Ferromagnetic PEA2Cr(Cl,Br)4 Two-Dimensional Perovskites.

Postsynthetic vapor-phase anion exchange in the ferromagnetic two-dimensional (2D) hybrid metal-halide perovskite, PEA2CrCl4 (PEA+ = phenethylammonium), is reported. Anion exchange using vaporous trimethylsilyl bromide (TMS-Br) is shown to drive complete conversion of solution-processed PEA2CrCl4 polycrystalline thin films to PEA2CrBr4. Low-temperature magnetic circular dichroism spectroscopy indicates ferromagnetic ordering in these PEA2CrCl4 and PEA2CrBr4 films. Via partial anion exchange of exfoliated flakes of PEA2CrCl4 single crystals, we demonstrate that it is possible to generate abrupt lateral PEA2CrCl4/PEA2CrBr4 magneto-heterointerfaces. Kinetic studies reveal that lateral heterostructure formation is dictated by rapid edge-site halide exchange followed by slower intralayer bromide diffusion, and there is negligible interlayer (3D) bromide or TMS-Br diffusion. The importance of the bulky PEA+ interlayer cation in suppressing 3D diffusion is highlighted by parallel anion-exchange experiments on MA2CrCl4 (MA+ = methylammonium), which instead show 3D exchange. Comparison of anion-exchange reactions in PEA2CrCl4, PEA2MnCl4, and PEA2PbCl4 shows that 2D bromide diffusion is slowest in PEA2CrCl4, attributed to the antiferrodistortive ordering found in this composition. In addition to demonstrating both postsynthetic composition control and heterostructure formation in ferromagnetic Cr-based 2D perovskites for the first time, these results also advance our fundamental understanding of ion-exchange processes in this relatively unexplored family of 2D perovskites, broadening opportunities for investigation and control of novel spin effects in low-dimensional metal-halide perovskites.

Precise Laser-Modulated Anion Exchange on Ultraflexible Perovskite Films for Multicolor Patterns.

Lead halide perovskite anion exchange reactions tend to be spontaneous and rapid. To achieve precise control of anion exchange and modulate the bandgaps of perovskites to meet the demands in full-color displays, a laser-induced liquid-phase anion exchange method is developed in this paper. CsPbBr3 perovskites embedded in a polymer matrix are converted to CsPb(BrxCl1-x)3 and CsPb(BrxI1-x)3 perovskites, realizing the shift from green fluorescence to blue and red fluorescence. By changing the laser parameters, the anion exchange extent and luminescence wavelength are precisely tuned, with the maximum tuning wavelength range of 431-696 nm. Due to the focusing properties of the laser, the spatial position of anion exchange can be precisely controlled, which is significant for realizing fast and accurate patterning without masks. Based on this method, blue patterns with different light-emitting wavelengths are fabricated. RGB three-color patterns on a single perovskite composite film are successfully prepared by further replacement of halogen ions. More importantly, the polymer matrix provides ultraflexibility and good stability for the films; even if the composite films are arbitrarily folded or repeatedly bent, they can still maintain good luminous intensity. This method will show great potential in the field of flexible, full-color displays.

Modulation between capacitor and conductor for a redox-active 2D bis(terpyridine)cobalt(II) nanosheet via anion-exchange

Ionic polymers are intriguing materials whose functionality arises from the synergy between ionic polymer backbones and counterions. A key method for enhancing their functionality is the post-synthetic ion-exchange reaction, which is instrumental in improving the chemical and physical properties of polymer backbones and introducing of the functionalities of the counterions. Electronic interaction between host polymer backbone and guest ions plays pivotal roles in property modulation. The current study highlights the modulation of responses to external electric field in cationic bis(terpyridine)cobalt(II) polymer nanofilms through anion-exchange reactions. Initially, as-prepared chloride-containing polymers exhibited supercapacitor behaviour. Introducing anionic metalladithiolenes into the polymers altered the behaviour to either conductive or insulative, depending on the valence of the metalladithiolenes. This modulation was accomplished by fine tuning of charge-transfer interactions between the bis(terpyridine)cobalt(II) complex moieties and redox-active anions. Our findings open up new avenue for ionic polymers, showcasing their potential as versatile platform in materials science.

Investigation on the Preparation and Performance of a Novel Sustained-Release Type Fluid Loss Agent for High-Temperature Resistant Oil Well Cement

Fluid loss agents (FLA) can reduce the fluid loss of cement paste by adsorption on the surface of the cement particles during cementing and decreasing the permeability of the cement cake, ensuring the safety of the cementing. As the exploration of the use of cement is progressing toward deeper and ultra-deeper layers, the use of FLA at high temperatures is urgently necessary. Hence, in this article, we describe the preparation of FLA with an organic/inorganic intercalated microstructure to meet the requirements of cementing at 210 °C. The anionic polymer FLA (ASDA) consists of 2-acrylamido-2-methylpropane sulfonic acid, sodium p-styrenesulfonate, N, N-dimethylacrylamide, and sodium 3-allyloxy-1-hydroxy-1-propylene. Organic-inorganic hybrid FLA, magnesium/aluminum-ASDA-hydrotalcite (Mg/Al-ASDA-LDHs) was prepared by intercalating ASDA into the interlayers of magnesium/aluminum layered double hydroxides (Mg/Al-LDHs) via an anion-exchange reaction. The results of thermal stability analysis showed that Mg/Al-ASDA-LDHs had better thermal stability than ASDA, with a decomposition temperature of 416 °C. In addition, the structure effectively mitigated the decrease in compressive strength of the mud caused by the carboxyl groups in the polymer. The Mg/Al-LDHs structure avoids the problem of reduced compressive strength of hardened cements due to conventional polymer FLA. The compressive strength of the cement containing Mg/Al-ASDA-LDHs increased by 57.4% after 7 days of curing compared with the cement containing 3% bwoc (“% bwoc” is defined as “by the weight of cement”) ASDA.

Highly selective and efficient Pb2+ capture using PO4-loaded 3D-NiFe layer double hydroxides derived from MIL-88A

Lead (Pb) contamination in water requires improved decontamination technologies. The addition of phosphate to precipitate Pb2+ is a widely used method for remediating Pb in soil and water, though it has certain limitations. This study focuses on novel 3D mesoporous layered double hydroxide (LDH) sorbents functionalized with phosphate anions for Pb2+ removal from contaminated waters. Our innovative strategy involves converting a sacrificial template metal-organic frameworks (MOFs) structure (MIL-88A(Fe)) into NixFe LDH, followed by an anion exchange reaction with phosphate anions. This process preserves the 3D microrod architecture of MIL-88A and prevents deleterious LDH particle aggregation. The synthesis results in stable microrod crystals, 1–2 μm long, composed of 3D assemblies of NixFe-PO4 LDH nanoplatelets with a specific surface area exceeding 110 m2/g. The novel LDH materials display fast adsorption kinetics (pseudo-second order model) and remarkably high Pb2+ removal performances (Langmuir isotherm model) with a capacity of 538 mg/g, surpassing other reported adsorbents. LDH-PO4 exhibits high selectivity for Pb2+ over competing ions like Ni2+ and Cd2+ (selectivity order is: Pb2+ > Ni2+ > Cd2+). Removal of Pb2+ from NixFeLDH/88A-PO4 involves various mechanisms, including surface complexation and surface precipitation of lead phosphate or lead hydroxide phases as revealed by structural characterization techniques.

Preparation of Quaternary Ammonium Separation Material based on Coupling Agent Chloromethyl Trimethoxysilane (KH-150) and Its Adsorption and Separation Properties in Studies of Th(IV).

In this research, the authors studied the synthesis of a silicon-based quaternary ammonium material based on the coupling agent chloromethyl trimethoxysilane (KH-150) as well as its adsorption and separation properties for Th(IV). Using FTIR and NMR methods, the silicon-based materials before and after grafting were characterized to determine the spatial structure of functional groups in the silicon-based quaternary ammonium material SG-CTSQ. Based on this, the functional group grafting amount (0.537 mmol·g-1) and quaternization rate (83.6%) of the material were accurately calculated using TGA weight loss and XPS. In the adsorption experiment, the four materials with different grafting amounts showed different degrees of variation in their adsorption of Th(IV) with changes in HNO3 concentration and NO3- concentration but all exhibited a tendency toward anion exchange. The thermodynamic and kinetic experimental results demonstrated that materials with low grafting amounts (SG-CTSQ1 and SG-CTSQ2) tended to physical adsorption of Th(IV), while the other two tended toward chemical adsorption. The adsorption mechanism experiment further proved that the functional groups achieve the adsorption of Th(IV) through an anion-exchange reaction. Chromatographic column separation experiments showed that SG-CTSQ has a good performance in U-Th separation, with a decontamination factor for uranium in Th(IV) of up to 385.1, and a uranium removal rate that can reach 99.75%.

Synthesis of P-Containing Polycyclic Aromatic Hydrocarbons from Alkynyl-phosphonium Salts.

This work presents a straightforward method for synthesizing a series of phosphorus-containing polycyclic aromatic hydrocarbons (P-PAHs) featuring an internal ylidic bond. The method involves anion exchange, alkyne annulation, and deprotonation reactions, enabling the efficient production of cyclic phosphonium salts, which serve as pivotal intermediates in the synthesis of P-PAHs. The alkyne annulation reaction exhibits high regioselectivity, ensuring the successful synthesis of λ5-phosphaphenanthrene isomers. Additionally, the incorporation of electron-withdrawing groups effectively stabilizes the internal ylidic bond of P-PAHs.

Perovskite-type samarium iron oxide adorned on reduced graphene oxide composite: A high-performance electrocatalyst for OER

The oxygen evolution process (OER), an essential and necessary reaction in water splitting to produce clean hydrogen fuel were investigated using a number of electrocatalysts. Non-noble metal catalysts are increasingly being used in place of noble metal catalysts because of their unique qualities, which include affordability, environmental friendliness and electrocatalytic activity. In this work, SmFeO3/rGO composite is prepared for an anion exchange reaction, which is used as catalyst on nickel foam in 1.00 M KOH electrolyte for OER. The fabricated electrocatalysts were confirmed by X-ray powder diffraction (XRD), Raman spectroscopy, energy-dispersive X-ray (EDX) spectroscopy and scanning electron microscopy (SEM). The BET determined surface area of SmFeO3/rGO composite is 51 cm2/g which is better for OER activity. The distinct structure of the nanocomposite displays increased surface area, increasing active sites with plentiful potential for charge transfer and prolonging the material's life. The electrochemical results represented that composite had lower overpotential (180 mV) with Tafel slope (34 mV/dec), displaying higher charge transfer during OER showing efficient electrocatalytic activity and high reliability of 55h. The reasons for lower overpotential and lower Tafel slope values were increased surface area and enhanced number of active spots in composite and also due to presence of non-kinetic effects that alter the Tafel slope values. The electrocatalyst may be able to facilitate the oxidation reaction based on all of these qualities. As a consequence, created composite reacts with outstanding efficacy for the OER process and energy conversion applications.

Surface properties of schwertmannite with different sulfate contents and its effect on Cr(VI) adsorption

Sulfate is a critical component of schwertmannite. However, the sulfate content of schwertmannite decreases with the increase in AMD-polluted river pH value, and its impact on the surface properties and Cr(VI) adsorption of schwertmannite remains unclear. To address this issue, different methods, including batch adsorption, N2 physisorption, scanning electron microscopy (SEM), potentiometric titration, X-ray photoelectron spectroscopy (XPS), attenuated total reflectance–Fourier transform infrared spectroscopy (ATR-FTIR) in combination with two-dimensional correlation spectroscopy (2D-COS) analysis, and surface complexation modeling (SCM) were employed. Our results showed that sulfate existed as both non-protonated bidentate-binuclear complexes and non-protonated outer-sphere complexes in schwertmannite. The surface morphology and particle size of schwertmannite were unaffected by the sulfate content. However, a decrease in sulfate content resulted in a drop in the negative charge on the surface of schwertmannite, which is conducive to particle aggregation. An increase in pH, on the other hand, raised the negative charge and encouraged the dispersion of the particles. And then, reducing the sulfate content of schwertmannite led to a decrease in acid-base buffer and Cr(VI) adsorption capacity of schwertmannite. The adsorption process of Cr(VI) by schwertmannite can be divided into two stages. In the first stage, Cr(VI) was adsorbed primarily through anion exchange reactions with the sulfate; however, the contribution of surface complexation gradually increased as the initial sulfate content decreased because of a reduced likelihood of anion exchange and an increase in the specific surface area of schwertmannite. Additionally, the behavior of sulfate and Cr(VI) in this stage could be predicted based on the initial sulfate content of schwertmannite. In the second stage, surface complexation with hydroxyl sites became the predominant mechanism of adsorption, which still exhibited great potential at higher Cr(VI) concentrations. Finally, the aforementioned hypothesis was used to establish a CD-MUSIC model, and the fitting results demonstrated that the density and Cr(VI) adsorption capacity of the sulfate site dropped as the sulfate content decreased, while the hydroxyl site was less impacted. The findings have provided insights into further understanding the properties of schwertmannite and its adsorption of Cr(VI).

ISFME extraction of As species from some real water samples using an imidazolium-based task-specific ionic liquid (TSIL): Synthesis and characterization

ABSTRACT To determine of arsenic species in real water samples using electrothermal atomic absorption spectrometry, a high-performance in-situ solvent formation microextraction technique has been developed using homogenous liquid – liquid microextraction concepts. The developed method was based on the use of a synthesized imidazolium-based ionic liquid (IL) modified with ammonium pyrrolidine dithiocarbamate as a task-specific ionic liquid (TSIL), which was chelated with As(III) and then converted to a hydrophobic IL using ammonium hexafluorophosphate in anion exchange reactions. As(V) was reduced to As(III), using a satisfied reducing agent, and the total amount of As was analyzed using ETAAS. TSIL acts simultaneously as an extracting solvent and a chelating agent. The characterization of the synthesized TSIL was performed using13CNMR and FTIR analyses. When optimal conditions were met, linear dynamic ranges of 0.5–50 µg/L and 0.5–20 µg/L were obtained in the determination of As(III) and total As, respectively. The limits of detection (LOD) and quantitation (LOQ) were determined to be 0.021 µg/Land 0.064 µg/L for the determination of As(III) (for concentration 20 µg/L), respectively, and the standard deviation (RSD%, n = 7) was 2.0%. To evaluate the validity of the method, it was successfully applied for As species determination in different real water samples.

Rapid room temperature synthesis of Mn-doped perovskite quantum dots for white-light-emitting diodes

All-inorganic perovskite quantum dots (PQDs) have excellent photoelectric performance, such as high photoluminescence quantum yield (PLQY), narrow full width at half-maximum (FWHM), and emission spectra covering the visible light wavelength. The emission color can be tuned over the full visible spectral region making them promising for white-light-emitting diodes (WLEDs). Further control over the optical and magnetic properties of PQDs can be achieved through doping of transition metal ions such as Mn2+ ions. In this paper, a rapid doping method is employed at room temperature by using strong-acid cation-exchange resin during the metal ions doping process, which shortens the doping time, and Mn:CsPb(Cl/Br)3 QDs were obtained. By controlling the reaction time between strong-acid cation-exchange resin and PQDs, we achieve different levels of manganese doping, resulting in a new, to the best of our knowledge, fluorescence peak at 600 nm. The introduction of strong-acid cation-exchange resin preserves the integrity of the PQD structure, while completing the doping within 30 min. Due to the low cost and mild reaction conditions of resin, it is expected that the Mn:CsPb(Cl/Br)3 QDs can be mass-produced in large quantities. In addition, in order to provide high-quality white light emission, and prevent anion exchange reactions when mixed with CsPbBr3 QDs, the CsPbBr3 QDs are coated with silicon. Finally, by combining ultraviolet-light-emitting diodes (UVLEDs) with the aforementioned PQD mixture, this paper successfully fabricates WLEDs and demonstrates its excellent photoelectric performance. The constructed WLEDs produce warm white light with a high color rendering index (CRI) of 91 and a high correlated color temperature (CCT) of 5966 K, and the luminous efficacy (LE) of WLEDs is 41lmW−1.

Photochromic Perovskite Nanocrystals for Ultraviolet Dosimetry.

Excessive ultraviolet (UV) radiation has serious damage to human's health, therefore the development of visible, portable, and wearable sensor for monitoring UV radiation, especially the cumulative UV dosage, is highly desired but full of challenges. Herein, a wearable and flexible UV dosimeter based on photochromic perovskite nanocrystals (PNCs) is designed. The obtained CsPbCl3 PNCs dispersed in dibromomethane (PNCs-DBM) undergo continuous, vivid, and multiple (from very weak purple to blue, cyan, and finally strong green) color change in response to UV radiation. It is demonstrated that the UV-induced degradation of DBM and subsequent anion-exchange reaction between CsPbCl3 and Br-, play a crucial role in the color change of PNCs-DBM. The properties of continuous fluorescence color change and enhanced fluorescence intensity enable the construction of sensitive and visible UV dosimeter. Furthermore, by integrated photochromic PNCs with flexible bracelet or PDMS substrate, a wearable UV sensor or a multi-indicator array for the detection of solar UV dosage is developed. This work may advance the fundamental understanding about photochromic perovskite, and show promising application of perovskite nanomaterials in easily fabricated, low-cost, visualized, and wearable solar UV dosimeter.

Anion Exchange in Semiconductor Magic-Size Clusters.

Ion exchange is an effective postsynthesis strategy for the design of colloidal nanomaterials with unique structures and properties. In contrast to the rapid development of cation exchange (CE), the study of anion exchange is still in its infancy and requires an in-depth understanding. Magic-size clusters (MSCs) are important reaction intermediates in quantum dot (QD) synthesis, and studying the ion exchange processes can provide valuable insights into the transformations of QDs. Here, we achieved anion exchange in Cd-based MSCs and elucidated the reaction pathways. We demonstrated that the anion exchange was a stepwise intermolecular transition mediated by covalent inorganic complexes (CICs). We proposed that this transition involved three essential steps: the disassembly of CdE1-MSCs into CdE1-CICs (step 1), an anion exchange reaction from CdE1-CICs to CdE2-CICs (step 2), and assembly of CdE2-CICs to CdE2-MSCs (step 3). Step 3 was the rate-determining step and followed first-order reaction kinetics (kobs = 0.01 min-1; from CdSe-MSCs to CdS-MSCs). Further studies revealed that the activity of foreign anions only affected the reaction kinetics without altering the reaction pathway. The present study provides a deeper insight into the anion exchange mechanisms of MSCs and will further shed light on the synthesis of QDs.

Co3+-Regulated electronic structure of NiCo2Sx nanoneedle arrays as high-rate cathode materials for durable alkaline Ni–Zn batteries

Alkaline zinc-based batteries have become a current research hotspot due to their high energy density and safety, but their low cycle stability and rate performance limit their commercial applications. Herein, vertically ordered NiCo2Sx nanoneedle arrays are prepared using different sulfidation concentrations based on the anion exchange reaction. The highly uniform nanoneedle arrays provide fast ion transport paths and abundant active sites, and the prepared NiCo2Sx@Ni foam (NiCo2Sx@NF) electrode has the excellent capacity (121.9 mAh g−1), stable cycle performance (91.1 % of capacity retention after 500 cycles), also achieves a maximum energy density of 636.3 Wh kg−1 and a maximum power density of 40.9 kW kg−1. This paper provides a more precise and accurate idea for preparing cathode materials for durable alkaline Ni–Zn batteries.

Influence of anion variation on dielectric response of amide functionalized benzimidazolium dicationic ionic liquids

The present work centered attention on novel ionic liquid (IL) based on dicationic benzimidazolium ion containing amide group (DBimIL) synthesized using dialkylation of N-ethyl benzimidazole to followed with anion exchange reaction. To explore the potential application of ILs, there is a great need to grasp their structural and physical properties. We have developed three different set of DBimIL based ionic liquids with chloride, hexafluorophosphate and perchlorate anions in aqueous media, respectively. Their structural features were studied using 1H, 13C-NMR, FTIR, and HRMS spectroscopy, respectively. The temperature-dependent dielectric characteristics of ILs were closely examined angular frequency in the range of 0.6–125 rad/s from 30 to 150 °C. The relationship between the structural and dielectric properties of ILs established. The dielectric parameters like dielectric constant, dissipation factor and the real part of ac conductivity were found to be affected significantly with the tuning of anionic moieties of ionic liquids. The ability of materials to store a charge in electromagnetic field was measured. From dielectric and electrical studies, to bring to an end, especially in particular way that the present IL systems have an enormous potential for the designing of modern-day energy storage devices.

High Na‐ion conductivity and mechanical integrity of anion‐exchanged polymeric hydrogel electrolytes for flexible sodium ion hybrid energy storage

AbstractThe polymeric gel electrolytes are attractive owing to their higher ionic conductivities than those of dry polymer electrolytes and lowered water activity for enlarged potential window. However, the ionic conductivity and mechanical strength of the Na‐ion conducting polymeric gel electrolytes are limited by below 20 mS cm−1 and 2.2 MPa. Herein, we demonstrate Na‐ion conducting and flexible polymeric hydrogel electrolytes of the chemically coupled poly(diallyldimethylammonium chloride)‐dextrin‐N,N′‐methylene‐bis‐acrylamide film immersed in NaClO4 solution (ex‐DDA‐Dex + NaClO4) for flexible sodium‐ion hybrid capacitors (f‐NIHC). In particular, the anion exchange reaction and synergistic interaction of ex‐DDA‐Dex with the optimum ClO4− enable to greatly improve the ionic conductivity up to 27.63 mS cm−1 at 25°C and electrochemical stability window up to 2.6 V, whereas the double networking structure leads to achieve both the mechanical strength (7.48 MPa) and softness of hydrogel electrolytes. Therefore, the f‐NIHCs with the ex‐DDA‐Dex + NaClO4 achieved high specific and high‐rate capacities of 192.04 F g−1 at 500 mA g−1 and 116.06 F g−1 at 10 000 mA g−1, respectively, delivering a large energy density of 120.03 W h kg−1 at 906 W kg−1 and long cyclability of 70% over 500 cycles as well as demonstrating functional operation under mechanical stresses.

Prevention of ion migration in lead halide perovskites upon plugging the anion vacancies with PbSe islands.

To circumvent the issue of halide ion exchange in perovskites, we have decorated CsPbBr3 and CsPbI3 nanocrystals with different sized PbSe nanoparticles and demonstrated that it effectively prevents anion exchange reaction in CsPbBr3/CsPbI3 nanoheterostructures (NHSs) as a consequence of halide vacancy passivation by the more covalent selenide anion.

Unprecedented C-F bond cleavage in perfluoronaphthalene during cobaltocene reduction.

The C-F bond activation of perfluoronaphthalene by 5-SIDipp led to the formation of dicationic salts with two fluorides (3·2HF2 ) or heptafluorodiborate (3·2B2F7) as counter-anions. The anion exchange reaction of 3·2B2F7 with NBu4PF6 afforded a highly luminescent 3·2PF6. The in situ addition of cobaltocene in the reaction mixture of 5-SIDipp and perfluoronaphthalene led to a distinct Co(I) species.