Internal charge transfer in metallicity sorted ferrocene filled carbon nanotube hybrids

Site selective high resolution photoemission and X-ray absorption have revealed the complex interplay between ferrocene and single-walled carbon nanotubes (SWCNTs) upon filling. The use of ultraclean and metallicity sorted nanotubes as starting material and a subsequent ferrocene filling, yields metallicity sorted hybrids, where the details of the internal charge transfer from Fe to the SWCNTs have been distinctly unravelled. An n-type doping of the SWCNTs has been identified, with the peculiarity that purely metallic tubes are prone up to 30% higher doping than their semiconducting counterparts. Concomitantly, the average Fe valency changes from 2 in ferrocene to 2.3 in the ferrocene/semiconducting SWCNT hybrids and to 2.4 in the ferrocene/metallic SWCNT hybrids. The origin of this extra charge transfer has been revealed to be ionic by resonant photoemission, which excludes a finite hybridization between the ferrocene filler and the SWCNTs. This does not only substantiate that the internal charge transfer determines the resulting electronic transport properties in the filled 1D carbon hybrids, but that the metallic or semiconducting character of the encapsulating tubes is crucial towards tailoring and regulating tunable 1D electronic transport properties in these materials that are highly desirable in nanoelectronics.     

Direct liquefaction of hydrolytic eucalyptus lignin in the presence of sulphided iron catalysts

The liquefaction of hydrolytic eucalyptus lignin has been studied in hydrogen donor and non-donor solvents in the presence of ferrocene and of ferrocene associated with sulphur or carbon disulphide. With the exception of tetralin, all reactions were carried out at supercritical conditions of the solvent. It was found that the yields of heavy oils increase significantly with the increase in hydrogen pressure in the non-donor solvents. The oil yields also increase with the density of the solvent but level out at densities higher than 0.30 g/ml. The consumption of molecular hydrogen is significant in the non-donor solvents; in the donor solvents the hydrogen is mostly transferred from the solvent itself. In the non-donor solvents, the oil yields depend strongly on the efficiency of the catalyst, but not in the donor solvents.     

吡螨胺的合成

吡螨胺是一种新型、高效的吡唑酰胺类杀螨剂,本文以中间体1-甲基-3-乙基-4-氯-5-吡唑甲酸和4-叔丁基苄胺合成,起始原料丙酰丙酮酸乙酯和4-叔丁基苄氯,总收率为61.23%(以丙酰丙酮酸乙酯计)。     

Diffusion coefficient of ferrocene in 1-butyl-3-methylimidazolium tetrafluoroborate - concentration dependence and solvent purity

The ionic liquid l-butyl-3-methylimidazolium tetrafluoroborate is used as electrolyte in the electrochemical determination of the diffusion coefficient of ferrocene as a function of concentration by cyclic voltammetry and chronoamperometry. An improved synthesis of the room temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate is described, which yields a product of high purity suitable for electrochemical purposes. A qualitative color test is discussed which allows the simple detection of silver ion contaminations. The diffusion coefficient of ferrocene appears to be concentration dependent in the solvent chosen.     

Preparation of Triazole-furnished Ferrocene Derivatives and their Polymer Complexes of Silver(I)

Condensation reactions of feroccenemethanol and of 1,1′-feroccenedimethanol with benzotriazole and triazole produce the ferrocene derivatives with one or two N-azole-containing substituents bonded to the cyclopentadienyl ligands. The bifunctional ferrocene derivatives, 1,1′-bis[(1,2,3-benzotriazol-1-yl)methyl]ferrocene and 1,1′-bis(1,2,4-triazoyl)ferrocene, reacts with [Ag(MeCN)₄]PF₆ to cause separation of the macromolecular complexes from the solution. The former ferrocene derivative with benzotriazole groups yields the complex of Ag(I) with Ag:ligand = 2:3. The Ag center is bonded to three triazole groups, forming a trigonal structure. Crystals of the complexes contain the ladder-shaped sheets formed by Ag(I) and the ligand, and these sheets are aligned in a staggered fashion. The latter ligand with 1,2,4-triazole groups and Ag(I) yield the 1:1 complex. Counter anions and MeCN molecules are contained within holes formed by the Ag(I) centers bonded with a metal–metal bond and the bifunctional ligands. NMR and UV measurement of the MeCN solution of these macromolecular complexes revealed dissociation of the ligand and degradation of the complexes in solution. This paper is dedicated to Professor Takakazu Yamamoto in honor of his pioneering research efforts and accomplishments in the fields of organometallics and π-conjugated polymers.     

Highly Enantioselective Synthesis of Secondary Alcohols using Triphenylborane

Asymmetric phenyl transfer reactions with triphenylborane as aryl source and a ferrocene‐based catalyst give secondary alcohols in high yields and excellent enantioselectivities.     

Friedel-Crafts-Acylierungen aliphatischer Verbindungen. VII. Friedel-Crafts-Acylierungen von Carbonsäurechloriden mit Maleinsäureanhydrid - ein neuartiger Zugang zu Tetronsäuren

Friedel-Crafts-Acylations of Aliphatic Compounds. VII. Friedel-Crafts-Acylations of Carboxylic Acid Chlorides with Maleic Acid Anhydride — a New Access to Tetronic Acids Reaction of succinic acid with propionyl chloride under Friedel-Crafts-reaction conditions yields 2-methyl-cyclopentan-1,3-dione. The related reaction of maleic acid anhydride with propionyl chloride does not yield 2-methyl-cyclopent-4-en-1,3-dione 7 , but a E/Z-mixture of the lactones 5 and 8 . By treating with hydrogen chloride in methanol or with thionylchloride in methanol the lactone mixture is converted to dimethyl (2Z, 4E)-3-hydroxy-2-methyl-hexa-2,4-diendioate 10 . By reaction with excessive sodium hydroxide the mixture of lactones is transformed into tetronic acid 11 . Structure determinations are based on u.v.-, i.r.-, m.s.- and n.m.r.-spectroscopy and on further chemical transformations. This tetronic acid synthesis represents an intramolecular addition of a carboxylate anion to an α, β-unsaturated carbonyl compound.     

Electrochemical characteristics and catalytic activity of polyaniline doped with ferrocene perchlorate

A new‐doped method based on electrochemical polymerization of aniline in the presence of ferrocene perchlorate and perchloric acid was presented. Polyanilines (PAn and PAnFc) were polymerized in the solution of perchloric acid and the solution containing ferrocene perchlorate and perchloric acid, respectively. Both flame atomic absorption spectrometry and infrared spectrum indicated that ferrocene perchlorate was assured to be doped into the polyaniline. We presumed that ferrocene perchlorate was combined via electrostatic adsorption onto the chain of polyaniline. The effect of pH on the electrochemical characteristics of PAn and PAnFc was studied by cycle voltammetry. Compared with PAn prepared in the absence of ferrocene perchlorate, PAnFc prepared in the presence of ferrocene perchlorate has a rather high electrochemical activity at pH > 4. The electrochemical oxidation of ascorbic acid (AA) on both PAn film and PAnFc film modified Pt electrode was also performed. The results indicated that the catalytic activity of the PAnFc film to AA was better than that of the PAn film. The anodic peak currents of AA (measured by constant potential amperometry) increased linearly with the concentration of AA in the range of 8.0 × 10^?5–1.0 × 10^?2 mol/L. The detection limit (S/N = 3) obtained was 1.0 × 10^?5 mol/L. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5633–5639, 2006     

Synthesis and Characterization of Ferrocene-Containing Hyperbranched Poly(aroylarylene)s

Ferrocene-containing hyperbranched poly(aroylarylene)s are prepared in satisfactory yields by one-pot copolycyclotrimerization of bis(aroylacetylene)s with a ferrocene-containing monoyne. The ferrocene content of the polymers can be varied by changing the monomer feed ratio, and copolymers with up to 41 mol% of ferrocene moiety can be readily prepared. All the polymers are thermally stable, losing little of their weights when heated to 340 °C. This article is dedicated to Professor Didier Astruc.     

Ferrocene-bound polyester resins

Seven ferrocene-bound polyester resins were prepared from fumaric acid and diethylene glycol in the presence of different ferrocene derivatives. To accomplish the incorporation of the organometallic moiety into the polyester resin chain, the cyclopentadienyl rings of ferrocene were substituted in the 1,1′ positions with reactive functional groups. The ferrocene derivatives used were: 1,1′-bis(1-hydroxyethyl) ferrocene 1 , 1,1′-ferrocene dicarboxylic acid 2 , and 1,1′-ferrocene diacetic acid 3 . The incorporation of an organometallic complex significantly increased the rate of the polyesterification process. In order of increasing rate enhancement, the effect was 2 < 3 < 1 . The effectiveness of ferrocene derivatives chemically incorporated into the polyester backbone during copolymerization with styrene was studied by monitoring the gel time, cure rate, and the resin properties. The efficiency of the copolymerization reaction of ferrocene-bound polymers with styrene decreased in the order 1 ≥ 3 > 2 . Mechanisms to account for these results are presented. Some of the strength related properties were also studied.     

Polymer–Ferrocene Conjugates Containing an Ester Function in the Connecting Links

Ferrocene, the parent of the metallocene family of organotransition metal compounds, has come to occupy a significant niche in cancer research. Developmental work in the authors' laboratory has been focused on the synthesis of antiproliferative ferrocene conjugates in which the bioactive ferrocene unit is covalently, yet bioreversibly bound (anchored) to water-soluble carrier polymers designed in accordance with requisite biomedical specifications. The anchoring link in most of these conjugates has been an aliphatic spacer containing the biofissionable amide group. In this communication the synthesis of a class of ferrocene conjugates is reported in which the ferrocene group is carrier-anchored through spacers containing an ester link, of interest here because of potentially different drug release behavior. The carriers are polyamides equipped with variously spaced hydroxyl side groups, to which the ferrocenylation agent, 4-ferrocenylbutanoic acid, is connected through esterification. The coupling reactions, mediated by carbodiimide agent and catalyzed by 4-(dimethylamino)pyridine, are carried out in DMF at temperatures not exceeding 65°C, and the water-soluble product polymers are isolated in yields of typically 70–85% by precipitation, aqueous dialysis, and freeze-drying. With the molar feed ratios chosen in these coupling experiments, the incorporation of ferrocene, assessed by ¹H NMR spectroscopy, corresponds to iron contents of roughly 2.5–5.5%, by mass. The conjugates will be included in a forthcoming bioactivity screening program.     

Aliphatic polyamides prepared by ester-amine polycondensation as potential drug carrier polymers

Aliphatic polyamides of interest as macromolecular drug carriers are synthesized by base-catalyzed polycondensation of aliphatic diesters with diamines. The reactions are conducted in the presence of anhydrous sodium carbonate at temperatures ranging from ambient to 65°C, initially in the undilute state. The addition of aprotic solvent at a later stage serves to maintain sufficiently low viscosity for proper homogenization. The comonomers, diethyl 3,6,9-trioxaundecanedioate and 4,7,10-trioxa-1,13-tridecanediamine, copolymerize to form polymer 1, a straight-chain polyamide devoid of specific functionality. Use of diethyl tartrate in lieu of the aforementioned diester leads to polyamide 2 possessing hydroxyl side groups. Other experiments in which diamines incorporating additional (secondary) amino groups are employed afford polyamides 3–8 containing such secondary amine functions as main-chain constituents. The water-soluble target polymers are crudely fractionated by aqueous dialysis (12000–14000 molecular mass cut-off) and collected by freeze-drying in yields of 20 to 40%. The low-yield range has been accepted in this investigation as the price to be paid for the realization of linear polyamide structures in accordance with compositional expectations, a requirement vital for the proper functioning of the polymers as drug carriers. The practicability of drug binding (conjugating) is exemplified by the coupling of ferrocene as a drug model to polyamide 5 via amide linkage. The water-soluble conjugate 5-Fc features an iron content corresponding to one ferrocene group in the repeat unit. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2143–2150, 1999     

Electronic Absorption Spectrum of a Ferrocene Analogue of Terephthal Green

Absorption spectra of Terephthal Green (I) and its ferrocene analogue (II) have been determined for solutions in 98% acetic acid and in ethanolic hydrogen chloride. Both dyesshow pronounced bathochromic shifts of the first- and second-frequency bands when compared with Malachite Green and its ferrocene analogue, respectively. These effects can be attributed to the presence of a strongly electron-withdrawing substituent in the parent dye. The colour of the ferrocene dye in acetic acid gradually fades.     

Preparation and structural characterisation of a novel ferrocene–amino acid conjugate

A new type of ferrocene–amino acid conjugate, 2-[(methoxycarbonyl)methyl]-2-aza[3]ferrocenophane (1), was obtained in a rather low yield via condensation reaction of 1,1′-bis(hydroxymethyl)ferrocene and glycine methyl ester in the presence of [RuCl₂(PPh₃)₃] as a catalyst. The compound was characterised by combustion analysis and by spectroscopic method, and its solid-state structure was established by single-crystal X-ray diffraction analysis. Compound 1 is reluctant towards alkylation with MeI but readily forms a stable picrate salt. Cyclic voltammetry experiments on 1 (in CH₃CN at Pt electrode) revealed the compound to undergo a one-electron reversible oxidation attributable to ferrocene/ferrocenium couple (E^o′ = ?5 mV vs. ferrocene itself), which shifts towards more positive potentials upon protonation with HCl.     

Synthesis,characterization, and pyrolysis of ferrocenyl unit containing organosilicon polymers

New polyferrocenylsiloxanes (PFSXs) and polyferrocenylsilazanes (PFSZs) with linear or linear‐cyclic structure were prepared. The ceramic yields of the polymers were estimated by thermogravimetric analysis (TGA) and bulk pyrolysis, which closely depend on molecular structures. Compared with that of their linear counterparts having comparable molecular weights, the ceramic yields of linear‐cyclic PFSX and PFSZ were much higher. The pyrolysis process was investigated by lysis character is (TGA) highly depend on their molecular weights and structures, infrared spectra, and pyrolysis‐gas chromatography‐mass spectra (Py‐GC‐MS) analysis. The results indicated rather amount of ferrocene‐based small molecules were formed during the pyrolysis of linear polymers in the range of 25–300°C, whereas the existence of crosslinking or branched structure in the linear‐cyclic polymers prohibited this transformation, and therefore, dramatically improved the ceramic yields. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

The direct synthesis of three enantiomerically pure diastereomers of 1-ferrocenylalkylamine from I-(−)-menthone,and the up-down stereoisomerism of ferrocene derivatives

Three ( 6a – c ) of the four conceivable diastereomeric 1-ferrocenylalkylamines can be synthesized from I-(−)-menthone and ferrocene in high enantiomeric purity. The many potential applications of such compounds, including their use as chiral templates in diastereoselective four component condensations (4CC, Ugi Reaction) are examined. Furthermore, NMR evidence for the first example of up-down-isomerism, a new type of conformational stereoisomerism of ferrocene derivatives, is discussed.     

Metallocene QACs: The Incorporation of Ferrocene Moieties into monoQAC and bisQAC Structures

Inspired by the incorporation of metallocene functionalities into a variety of bioactive structures, particularly antimicrobial peptides, we endeavored to broaden the structural variety of quaternary ammonium compounds (QACs) by the incorporation of the ferrocene moiety. Accordingly, 23 ferrocene-containing mono- and bisQACs were prepared in high yields and tested for activity against a variety of bacteria, including Gram-negative strains and a panel of clinically isolated MRSA strains. Ferrocene QACs were shown to be effective antiseptics with some displaying single-digit micromolar activity against all bacteria tested, demonstrating yet another step in the expansion of structural variety of antiseptic QACs.     

Iron versus ruthenium oxidation in 1,1′-bis(diphenylphosphino)ferrocene–ruthenium(II) complexes: EPR and spectroelectrochemical evidence

Oxidation of [Cp^*RuH(dppf)] (1), dppf=1,1′-bis(diphenylphosphino)ferrocene, and [(Cym)RuCl(dppf)](PF₆) (2), Cym=p-cymene, occurs at ruthenium for 1 but yields a ferrocenium species for compound 2.     

聚醛酮二茂铁的合成

以三氯甲烷做溶剂,无水三氯化铝作催化剂,由醋酐同二茂铁反应制得1,1′ 二乙酰基二茂铁(Ⅰ)粗品。控制反应温度在4～6℃,搅拌反应6h。经环己烷重结晶,得到Ⅰ纯品。甲醇做溶剂,甲醇钠作催化剂,在0℃使对苯二甲醛与Ⅰ反应5h,制得具有光电性质、结构稳定的聚醛酮二茂铁。测定了二茂铁、Ⅰ、聚醛酮二茂铁的最大吸收波长,分别是430nm,456nm,332nm。聚醛酮二茂铁的分子量约40×103。     

聚苯乙烯二醋酸碘苯在萘普生合成中的应用

2-萘甲醚(1)在无水AlCl3催化下与丙酰氯反应得6-甲氧基-2-丙酰萘(2),(2)在原甲酸三乙酯、硫酸下采用聚苯乙烯二醋酸碘苯催化进行1,2-芳基迁移重排得2-(2-(6-甲氧基萘基))丙酸乙酯(3),(3)在氢氧化钠水溶液中水解、酸化得萘普生(4)。总收率约47.4%(以2-萘甲醚计)。试验研究了影响合成2-(2-(6-甲氧基萘基))丙酸乙酯(3)的多种因素,如:硫酸的用量、原甲酸三酯的用量以及聚苯乙烯碘苯的回收利用。