Temperature dependence of kinetics and diffusion coefficients for ferrocene/ferricenium in ammonium-imide ionic liquids

The electrochemical behavior of ferrocene (Fc) and ferricenium (Fc⁺) was investigated by cyclic voltammetry with convolutional and semi-differential electroanalyses in the temperature range 298-373 K in the hydrophobic room temperature ionic liquid systems consisting of bis(trifluoromethanesulfone)imide anion with quaternary ammonium cation. The experimental results indicated that the redox reaction of Fc/Fc⁺ was reversible in this ionic liquid and the charge-transfer rate constant (k⁰) has been obtained. Mass transport towards the electrode is a simple diffusion process and the diffusion coefficient (D) for Fc/Fc⁺ has been also calculated. These results indicated that the k⁰ and D increased with increasing temperature in ionic liquids. The validity of the Arrhenius law was verified by investigating the temperature dependences of k⁰ and D.     

Novel Organometallic Aromatic Azo Polyesters Based on Ferrocene

Some ferrocene containing aromatic azo polyesters were prepared by condensing 1,1-ferrocenedicarbonyl chloride with different azo groups containing aromatic diols, which were synthesized by diazotization coupling reaction from aromatic diamines. The polymeric products were separated as two portions on the basis of their solubility and subsequently characterized by their elemental analysis and FTIR spectral studies. Thermal properties of the products were measured by differential scanning calorimetry and thermogravimetry and the activation energies of pyrolysis were calculated using Horowitz and Metzger's method. The molecular weights of the soluble portions were determined by gel permeation chromatography (GPC) and these portions were also characterized by their inherent viscosities and UV-Vis spectroscopic studies.     

二茂铁及其衍生物的应用

综述了二茂铁及其衍生物在添加剂、燃速催化剂、医学、液晶材料、感光材料以及二茂铁有机磁体等方面的应用和最新研究进展。     

Experimental investigation of the fire extinguishing capability of ferrocene-containing water mist

This study focuses on the fire-suppression capabilities and corrosive properties of ferrocene dispersions. The motivation behind the present study was to develop a high-performance, phosphorus-free fire suppressant. Aqueous dispersions containing micron-sized ferrocene particles and surfactants were prepared using sonication techniques. In this study, Triton X-100 (TX), Noigen TDS-80 (NT), Tween 60 (T60), and Tween 80 (T80) were used as surfactants. Suppression experiments involving pool fires clearly indicated that aqueous ferrocene dispersions containing TX and micron-sized ferrocene with a d₅₀=16.9 μm exhibit shorter extinguishing times than a conventional wet chemical. Corrosion trials using steel plates immersed in ferrocene dispersions containing TX confirmed that there was no pitting corrosion, implying that ferrocene dispersions containing TX do not present a corrosion risk.     

Synthesis and microwave absorption properties of SiC nanowires reinforced SiOC ceramic

Silicon carbide nanowires (SiC NWs) reinforced SiOC ceramics were fabricated through in situ growth of SiC NWs in SiOC ceramics by pyrolysis of polysiloxane. SiC NWs were in situ formed by the addition of ferrocene, the content of SiC NWs increased with the increases of annealing temperature and ferrocene content. Due to the formation of SiC NWs in the inter-particle pores of SiOC ceramics, the SiOC particles were bridged by SiC NWs, which led to the increase of electrical conductivity. With the increase of SiC NWs content, the real permittivity and the imaginary permittivity increased from 3.63 and 0.14 to 10.72 and 12.17, respectively, and the minimum reflection coefficient decreased from −1.22 dB to −20.01 dB, demonstrating the SiOC ceramics with SiC NWs had a superior microwave-absorbing ability.     

某些二茂铁磺酸酯的合成

将二茂铁磺酰氯与醇在碱存在下直接反应，或将醇或酚制成钠盐后再与二茂铁磺酰氯反应，制备了包括二茂铁磺酸甲酯在内的一系列共十个二茂铁磺酸酯衍生物，并对这些化合物的物理性质、红外光谱及质子核磁共振谱进行了研究。     

Ferromagnetic conductive polypyrrole doped with water-soluble ferrocene derivative

In this paper, we report synthesis and characterization of polypyrrole (PPy) doped with a new water-soluble ferrocene derivative of p-ferrocenyl benzene sulfonic acid (BSAFc). The ferromagnetic conductive PPy powder was obtained by chemical polymerization. XPS and FT-IR were used to clarify the structure of PPy powder and confirm the existence of ferrocene group in the PPy powder. A complete understanding of the electronic structure of iron in PPy powder was achieved by Mössbauer spectrum measured at room temperature, which indicates that ⁵⁷Fe in the PPy powder is in the low-spin electronic structure of trivalence. The PPy powder exhibited an electrical conductivity of about 10⁰ S/cm at room temperature, a coercive force of 20 Oe and saturation magnetization of 1.76 emu/g at low temperature of 1.8 K. Thermogravimetric analysis (TGA) showed that the PPy powder had the same thermostability as normal PPy. The electro-active PPy freestanding film was also synthesized by doping with the new water-soluble ferrocene derivative via electrochemical polymerization, which is significant for developing the application of the PPy film in secondary battery, membrane electrode and so on.     

Electrochemical studies of ferrocene in a lithium ion conducting organic carbonate electrolyte

We carried out a detailed study of the kinetics of oxidation of ferrocene (Fc) to ferrocenium ion (Fc⁺) in the non-aqueous lithium ion conducting electrolyte composed of a solution of 1 M LiPF₆ in 1:1 EC:EMC solvent mixture. This study using cyclic (CV) and rotating disk electrode (RDE) voltammetry showed that the Fc⁰/Fc⁺ redox couple is reversible in this highly concentrated electrolyte. The ferrocene and ferrocenium ion diffusion coefficients (D) were calculated from these results. In addition, the electron transfer rate constant (k⁰) and the exchange current density for the oxidation of ferrocene were determined. A comparison of the kinetic data obtained from the two electrochemical techniques appears to show that the data from the RDE experiments are more reliable because they are collected under strict mass transport control. A Tafel slope of c.a. 79 mV/decade and a transfer coefficient α of 0.3 obtained from analysis of the RDE data for ferrocene oxidation suggest that the structure of the activated complex is closer to that of the oxidized specie due to strong interactions with the carbonate solvents. The experiments reported here are relevant to the study of redox reagents for the chemical overcharge protection of Li-ion batteries.     

二茂铁硫代乙酰吗啉合成工艺的研究

以二茂铁和乙酰氯为原料,二氯甲烷为溶剂,氧化锌为催化剂,进行傅-克酰基化反应合成乙酰基二茂铁(主产物为单乙酰基二茂铁),并通过正交实验得出最佳反应条件:n(二茂铁)∶n(乙酰氯)∶n(氧化锌)=1∶3∶1.2,反应时间45 min,在该条件下产率为86%;然后,乙酰基二茂铁与硫磺、吗啉发生Willgerodt-Kinder反应,合成二茂铁硫代乙酰吗啉,通过正交实验得出最佳条件:n(乙酰基二茂铁)∶n(硫磺)∶n(吗啉)=1∶3∶6,反应时间4 h,在该条件下产率为65%,并经元素分析、IR、1HNMR表征确定为目标产物。     

Ferroceneboronic acid for the electrochemical probing of interactions involving sugars

Ferroceneboronic acid (FcBA) was used as a redox-active probe suitable for monitoring of diol–boronate interactions. Voltammetric and amperometric measurements allowed to detect FcBA forms – free and bound in the boronate complex. In this way, the complexation interaction was studied for a set of saccharide molecules as model diols and the corresponding affinity equilibrium constants were determined. A shift of the peak potential on voltammograms accompanying formation of the boronate complex with FcBA was proposed as a probe for electrochemical characterization of surface-confined diol-containing structures. The model experiments were carried out using sorbitol- and 1,6-hexandiol-modified polyepichlorhydrin conjugates deposited on the electrodes; the former compound was able to form the boronate complex while no change of the peak potential for the latter conjugate was observed. This approach seems promising for artificial bioelectronic affinity receptors and technology of reagentless biosensors where the binding interaction directly stimulates a measurable electrochemical event.