Showing papers on "Ferrocene published in 1978"

Preparation of chemically derivatized platinum and gold electrode surfaces. Synthesis, characterization, and surface attachment of trichlorosilylferrocene, (1,1'-ferrocenediyl)dichlorosilane, and 1,1'-bis(triethoxysilyl)ferrocene

Abstract: The synthesis and characterization of three ferrocene-centered, hydrolytically unstable, surface derivatizing reagents and their attachment to pretreated (anodized) Pt and Au electrode surfaces are described. Trichlorosilylferrocene (1) has been isolated from the reaction of SiCl/sub 4/ and lithioferrocene; (1,1'-ferrocenediyl)dichlorosilane (II) has been isolated from the reaction of SiCl/sub 4/ and 1,1'-dilithioferrocene; and 1,1'-bis(triethoxysilyl)ferrocene (III) has been isolated from reaction of ClSi(OEt)/sub 3/ with 1,1'-dilithioferrocene. The species I, II, and III have been fully characterized by /sup 1/H NMR, mass, and uv-vis spectra and elemental analyses. All are moisture sensitive and are capable of derivatizing anodized Pt surfaces. Detailed studies for derivatization of anodized Au using II are described. In many respects the properties of derivatized Au electrodes parallel those for derivatized Pt. Such derivatized electrodes exhibit persistent cyclic voltammetric waves at a potential expected for an electroactive ferrocene derivative. Greater than monolayer coverages are found in each case, as determined by the integration of the cyclic waves. The cyclic voltammetric parameters are as expected for a reversible, one-electron, surface-attached electroactive system except that the peak widths are broader than theoretical. This is attributed to chemically distinct ferrocene centers resulting from the oligomerization of the derivatizing reagent during the derivatization procedure.

Chemically derivatized n-type semiconducting germanium photoelectrodes. Persistent attachment and photoelectrochemical activity of ferrocene derivatives

Abstract: Attachment of trichlorosilylferrocene (I) and (1,1'-ferrocenediyl)dichlorosilane (II) to pretreated n-type Ge surfaces by hydrolytic reaction is described. Characterization of the derivatized surface by cyclic voltammetry in C/sub 2/H/sub 5/OH or CH/sub 3/CN solutions of 0.1 M (n-Bu/sub 4/N)ClO/sub 4/ shows persistently attached electroactive groups. Cyclic waves persist for hundreds of scans between oxidized and reduced form of the attached electroactive species. The position of the anodic current peak depends on the illumination intensity, though an anodic peak does obtain in the dark at approximately 0.5 V vs. SCE for attached I or II. Illumination moves the anodic peak by up to approximately 200 mV more negative, consistent with expected photoeffects for an n-type semiconductor. Comparison of the derivatized electrode with a naked n-type Ge photoelectrode exposed to electrolyte solutions of ferrocene shows that the interface energetics and kinetics are essentially unchanged by the surface derivatization. Conversion of light to electricity using an n-Ge-based photoelectrochemical cell is possible, but output parameters are very low for an electrolyte solution containing ferrocene and ferricenium. 10 figures.

Ligand exchange reactions between ferrocene and 9,10-dimethylanthracene

Abstract: The reaction of 9,10-dimethylanthracene (8) with ferrocene (FcH) in the presence of AlCl3–Al in decalin gave the stereospecifically hydrogenated product, η6-cis-(endo-9,10-dihydro)-9,10-dimethylanthracene-η5-cyclopentadienyliron cation (10a), the hydrogenation at C-9,10 being cis and endo or on the same side as the cyclopentadienyliron (CpFe) moiety. When cis-9,10-dihydro-9,10-dimethylanthracene, generated from 10a by photolysis or pyrolytic sublimation, was used as the arene in the ligand exchange reaction, complexing with the CpFe group could occur from either side of the ring system, giving rise to a mixture of 10a and the η6-cis-(exo-9,10-dihydro)-9,10-dimethylanthracene-η5-cyclopentadienyliron cation (10b). The η6-cis-9,10-dihydro-9,10-dimethylanthracene-trans-bis-η5-cyclopentadienyliron dication, with the two CpFe groups trans, was also prepared either from a stepwise ligand exchange using 10a or directly from reaction of 8 using an excess of FcH. A mechanism is proposed for the hydrogenation that h...

X-Ray crystallographic studies on ferrocene included in a thiourea host lattice

Abstract: X-Ray crystallographic studies on a 3 : 1 thiourea–ferrocene clathrate have been carried out at 295 and 100 K. The crystal structure of the high-temperature form has been determined from diffractometer data by Patterson and Fourier methods. Crystals are rhombohedral, space group Rc with Z= 6 in a unit cell based on the hexagonal setting of a= 16.360(3) and c= 12.395(2)A. The structure has been refined by least-squares methods to R 0.079 for 711 observed reflections. It consists of thiourea molecules which form a honeycomb of channels by spiralling with a pitch of 120 ° parallel to the c axis. Within these channels, sites of point symmetry 32 are occupied by the ferrocene iron atoms. The cyclopentadienyl rings are disordered and the time-averaged picture shows regions of three-dimensionally delocalised cyclopentadienyl electron density around the iron atoms.

The Reaction of ortho-Palladated Ferrocene Complexes with Olefins

Abstract: ortho-Palladation products of (dimethylaminomethyl)ferrocene and 2-pyridylferrocene were treated with various olefins under mild conditions. A variety of unusual 1,2-disubstituted ferrocene derivatives were obtained from these reactions.

Structure of the ferrocene carboxaldehyde mesophase by X-ray diffraction and Mössbauer spectroscopy

Abstract: Ferrocene carboxaldehyde is unusual in that whilst its molecular shape is of low symmetry it shows a mesophase between 44°C and the m.p. (123°C). The nature of this phase has been investigated by X-ray diffraction and Mossbauer spectroscopy. It is shown to be an orientationally disordered molecular crystal, with a simple f.c.c. lattice (a= 999 ± 2 pm). The molecules are, on average, randomly oriented about their centres of mass C (rCFe= 46 pm). Short range correlations in molecular arrangement are accounted for by a Gaussian distribution of molecular centres with 〈U2x〉½= 69 pm. In contrast the r.m.s. displacement of the Fe in the room temperature phase is ∼ 20 pm as for ferrocene.

Synthesis of [2,2] ferrocenophane-1,13-diene

Abstract: [2,2] Ferrocenophane-1,13-diene (1) was synthesized via the intermolecular coupling of ferrocene-1,1′-dicarbaldehyde (2) with TiCl4–LiAlH4. The catalytic hydrogenation of 1 led to the formation of [2,2] ferrocenophane (7). An alternate approach to the synthesis of 7, involving the reductive coupling of 1,1′-bis(hydroxymethyl)ferrocene with TiCl4–LiAlH4 is described.

Studies on Ferrocene and its Derivatives, VI. Cyclocondensation Reactions of Some Ferrocenyl Anils

Abstract: Die Kondensation von Ferrocenaldehyd mit verschiedenen Aminen fuhrt zu den Schiffschen Basen (I)-(IV).

Interfacial synthesis of condensates of dicyclopentadienyltitanium dichloride and 1,1′s-diacylferrocene oximes

Abstract: Polymers of the below form were prepared by the interfacial method via condensation of Cp2TiCl2 with ferrocene oximes. A brief kinetic investigation is described. Durch Grenzflachenpolykondensation von Cp2TiCl2 mit Ferrocenoximen wurden Polymere der folgenden Struktur hergestellt. Kinetische Untersuchungen werden beschrieben.

Studies on Phenylazoferrocene and Derivatives

Abstract: Mercuration of phenylazoferrocene gave (2-chloromercuri)-phenylazoferrocene as well as a mixture of meso- and d,1-bis-(2-phenylazoferrocenyl)mercury. Iodination of either mercurial gave a heat and light sensitive compound, (2-iodo)phenylazoferrocene. Diazotization of aminoferrocene with isoamyl nitrite in refluxing benzene has produced a low yield of phenylferrocene and ferrocene.

Organometallic polymers. IV. Organometallic modifications of halogen-containing polymers

Abstract: The synthesis of ferrocene-containing polymers by chemical modification of chlorinated polyethylenes, polyvinyl chloride (PVC), and other halogenated polymers, under Friedel-Crafts conditions, is described. The effect of reaction conditions on the structure and composition of the products obtained with various substrates was investigated. Soluble polymers of up to 62% ferrocene content were obtained. In most cases, substitution was accompanied by dehydrohalogenation. The ferrocene-to-vinylene ratio was higher in the reaction products of chlorinated polyethylenes than in those of PVC.

Organometallic polymers. V. Synthesis and properties of metallocene‐modified polymers

Abstract: The reaction of metallocenes with solutions of polydienes and halogenated polymers, under Friedel-Crafts conditions, has now been applied to the surface modification of solid polymer films. The reaction of ferrocene with chlorinated polyethylene films appears to proceed by a fast substitution step followed by a slower diffusion-controlled step. The stress–strain curves of surface-modified films, as well as of solution-cast polymetallocene films, have been examined by means of a bursting-strength apparatus. The weathering behavior of metallocene-modified polymers has been studied in both natural and accelerated conditions. Studies on the effect of ageing on composition and properties by spectrophotometric and mechanical measurements indicate that the photooxidative resistance of polymers is improved significantly by metallocene modification. Additionally, modified films have been found to be effective as clear shields for the protection of vulnerable substrates against photodegradation. The observed darkening of the irradiated films could be due to a thermal reaction between metallocene and photolytically generated macroperoxides.