bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel, Readily Accessible Lactosaminyl Donor: N-Trichloroethoxycarbonyl-hexa-O-benzoyl-β-d-lactosaminyl Fluoride
Authors: Kaji Eisuke , Lichtenthaler Frieder W , Osa Yumiko , Zen Shonosuke 
Published: July 2006

Abstract
A simple, preparatively satisfactory 10-step sequence is described for converting lactose into a novel, suitably blocked lactosaminyl donor: N-Trichloroethoxycarbonyl-β-d-lactosaminyl fluoride (5). The key intermediate in this conversion is the particularly well-accessible oxime of lactosulosyl bromide (52% for the 6 steps from lactose), which on α-glycosidation with p-methoxybenzyl alcohol, oxime reduction, N-protection by Troc chloride, and the anomeric fluorination yields 5 (37% for the 4 steps). The utility of 5 as an effective donor was proved by the β-selective glycosylation of the primary 6-OH of 1,2 : 3,4-di-O-isopropylidene-α-d-galactopyranose (14) and the 3-OH of methyl 2,4,6-tri-O-benzyl-β-d-galactopyranoside (16), both affording the respective trisaccharides 15 and 18 in high yields. The latter, when subjected to N-deprotection, N-acetylation, and de-O-acylation gave, in 42% yield based on donor 5, β-d-Gal-(1→4)-β-d-GlcNAc-(1→3)-β-d-Gal-(1→Me, a core trisaccharide unit of immunologically important carbohydrate antigens.
Catalytic Effect of Five-Coordinate Organotin Bromide or Tetraphenylstibonium Bromide on the Chemo- and Stereoselective Addition of Tin Enolate to α-Halo Ketone
Authors: Yasuda Makoto , Oh-hata Tatsuhiro , Shibata Ikuya , Baba Akio , Matsuda Haruo , Sonoda Noboru 
Published: July 2006

Abstract
Two types of catalysts, five-coordinate organotin bromides and tetraphenylstibonium bromide, similarly promoted the selective addition of tin enolates to the carbonyl moiety in α-halo ketones. The reaction with 2-chlorocyclohexanones and the enolates gave chlorohydrins bearing chloro- and hydroxyl groups in the cis-conformation. Chemoselective carbonyl addition to acyclic α-halo ketones was followed by effective cyclization to 2-(2-oxoethyl)oxiranes. The structural and bonding analogy of both catalysts may be responsible for the similar catalytic activities which induced the chemo- and stereoselective addition.
Syntheses and Structures of Novel Fused-Ring Systems Containing Six or Seven Sulfur Atoms: 2,3:5,6-Bis(ethylenedithio)thieno[3,2-b]thiophene and 3,4:6,7-Bis(ethylenedithio)thieno[3,2-c][1,2]dithiin
Authors: Tanaka Motoko , Ishida Takayuki , Nogami Takashi , Yoshikawa Hajime , Yasui Masanori , Iwasaki Fujiko 
Published: July 2006

Abstract
Novel fused-ring molecules, 2,3:5,6-bis(ethylenedithio)thieno[3,2-b]thiophene and 3,4:6,7-bis(ethylenedithio)thieno[3,2-c][1,2]dithiin, were synthesized for the development of new conducting organic salts. They have six and seven sulfur atoms, respectively. Their molecular and crystal structures were determined by X-ray crystallographic analyses. Their oxidation potentials were measured, compared with those of the related donor molecules, and analyzed by a molecular-orbital calculation.
Enzymatic Resolution of the Sterically Hindered myo-Inositol Derivative
Authors: Ling Lei , Ozaki Shoichiro 
Published: July 2006

Abstract
A modification of the enzymatic resolution has been developed for the resolution of the sterically hindered myo-inositol derivative. In this method, a side chain, which contains a terminal hydroxyl group on it, was introduced to a chiral hydroxyl group, and the terminal hydroxyl group on side chain was used for resolution. Enzymes could recognize the asymmetric center through the distal terminal hydroxyl group. Racemic 3,4,5,6-O-tetrabenzyl-myo-inositol was resolved by this method.
Intramolecular Hydrogen-Atom Transfer in 2-Alkylbenzoyloxyl Radicals as Studied by Transient Absorption Kinetics and Product Analyses on the Photodecomposition of Bis(2-alkylbenzoyl) Peroxides
Authors: Wang Jun , Tsuchiya Masahiro , Tokumaru Katsumi , Sakuragi Hirochika 
Published: July 2006

Abstract
The pulsed-laser excitation of bis(2-methylbenzoyl) peroxide at 308 nm in acetonitrile afforded a broad absorption band at 500—800 nm due to 2-methylbenzoyloxyl radicals. The decay of this band accompanied the growth of another band at 350 nm due to 2-carboxybenzyl radicals produced by an intramolecular hydrogen-atom transfer from the neighboring 2-methyl group; the rate constant was 1.7 × 107 s−1 at 23 °C, the activation energy and frequency factor being 17 kJ mol−1 and 1010.5 s−1, respectively. The rates for intramolecular hydrogen-atom transfer in 2-MeCH2C6H4CO2· and 2-PhCH2C6H4CO2· are much higher than that in 2-CH3C6H4CO2·, since the parent peroxides, (2-MeCH2C6H4CO2)2 and (2-PhCH2C6H4CO2)2, exhibited only 350-nm bands ascribable to the corresponding 2-carboxybenzyl radicals, even immediately after laser excitation.
The pulsed-laser photolyses of the above-mentioned peroxides afforded PhCH2R, 2-HOCOC6H4CH(R)CH2CN, and 2-HOCOC6H4CHRCHRC6H4CO2H-2 (R = H, Me, and Ph) as the main products in acetonitrile. The formation of PhCH2R is explained in terms of the contribution of two-bond fission of the O–O and C(α)–C bonds of the peroxide in the excited singlet state in competition with O–O bond cleavage followed by an intramolecular hydrogen-atom transfer.
Study of the Fatigue Process and the Yellowing of Polymeric Films Containing Spirooxazine Photochromic Compounds
Authors: Baillet Gilles , Giusti Gérard , Guglielmetti Robert 
Published: July 2006

Abstract
Photochromic polyurethane films containing 5-substituted 1,3-dihydro-3,3-dimethyl-1-alkylspiro[2H-indole-2,3′-[3H]pyrido[3,2-f][1,4]benzoxazine] and 1,3-dihydro-1,3,3-trimethylspiro[2H-indole-2,3′-[3H]naphth[2,1-b][1,4]oxazine] were degraded under xenon light exposure. The loss of the photochromic response was monitored by spectrophotometry as a function of the irradiation time; meanwhile, the photoproduct formation and the amount of photochromic material still available were analyzed by chromatography after liquid–solid extraction. At the same time, the fade rates were monitored after flash-excitation photolysis or after the photostationary state during degradation. It was clearly demonstrated that the loss of photochromism was due exclusively to a photooxidation process of the initial dye, and not to an acceleration of the bleaching or a potential screen effect caused by the photoproducts.
In-situ Kinetic Studies on Direct Fluorination of Thin Polyethylene Films with QCM
Authors: Hara Noriaki , Fukumoto Hisatoshi , Watanabe Masahiro 
Published: July 2006

Abstract
Fluorination of polyethylene (PE) films with fluorine gas was studied by using the quartz crystal microbalance technique from the interest for the preparation of wet-proofed carbon black with fluorinated polyethylene (FPE) film for application to gas-diffusion electrodes in fuel cells. The fluorination reaction proceeds clearly in three separated steps, i.e., the first transient step, the 2nd step controlled by the chemical reaction between F2 and PE molecules, and the 3rd step controlled by the diffusion rate of dissolved F2 in FPE. The complete fluorination of PE films of ca. 2—10 μm in thickness can be achieved after sufficient reaction time. It was found that the fluorination at the 2nd step obeys the first order kinetics regarding F2 concentration with the activation energy of only 34.3 kJ mol−1. The fluorination at the 3rd step proceeded linearly with the square-root of the reaction time. Diffusion parameters and apparent activation energies for the fluorination at the 3rd step were determined by solving Fick’s diffusion equation based on those experimental data. Both of them were very large in comparison with that for un-reacting gases, which were ascribed to the fluorination step proceeded by the reactive diffusion process.
Halofluorination of Alkenes Using Dilute Hydrofluoric Acid
Authors: Kuroboshi Manabu , Hiyama Tamejiro 
Published: July 2006

Abstract
Iodofluorination of alkenes was achieved with N-iodosuccinimide, potassium hydrogendifluoride, and 1 M hydrofluoric acid using tetrabutylammonium fluoride as a phase-transfer catalyst. The active fluorinating reagent was shown to be tetrabutylammonium dihydrogentrifluoride by preparing the salt in a different way and by effecting the same transformation under anhydrous conditions. Bromofluorination of alkenes also was carried out using 1,3-dibromo-5,5-dimethylhydantoin. Treatment of the I–F adducts with DBU afforded fluoro olefins stereospecifically.
The Quenching of Lumichrome Fluorescence by β-Cyclodextrin : Evidence for Inclusion Complex
Authors: Sarkar Biswajit , Das Utpal , Bhattacharyya Subirnath , Bose Swapan K 
Published: July 2006

Abstract
The formation of inclusion complex between lumichrome and β-cyclodextrin was studied by fluorimetric and solubility methods. The accessibility of lumichrome to the iodide ion in presence of β-cyclodextrin was also studied. The equilibrium constant of formation of this inclusion complex, K, determined by fluorometric method and solubility method is 966 and 491 mol dm−3, respectively.
Semiconductor Photocatalysis. ZnS-Nanocrystallite-Catalyzed Photooxidation of Organic Compounds
Authors: Yanagida Shozo , Kawakami Hiroshi , Midori Yoshihide , Kizumoto Hirotoshi , Pac Chongjin , Wada Yuji 
Published: July 2006

Abstract
Freshly prepared ZnS (nano-ZnS) suspensions catalyze photooxidation of organic substrates under band-gap irradiation with water as a good electron acceptor, while H2 evolves concomitantly. The organic substrates with hetero atoms or carbon–carbon double bonds (π-bonds), such as triethylamine (TEA), diethylamine (DEA), methanol, ethanol, cyclopentene, cyclohexene, 2-methylfuran, toluene, and ethylbenzene, undergo effective one-hole oxidation. This leads to efficient carbon–carbon bond forming reactions between cumulatively formed radicals at the α-carbon adjacent to the hetero atom or the π-bond. The photooxidation in the presence of a larger quantity of water results in successive oxidation of the intermediary α-carbon radicals, giving the two-hole oxidation products, e.g., DEA and acetaldehyde from TEA, and formaldehyde from methanol. The formation of the intermediary α-carbon radical has been clarified by ESR analysis using 2-propanol as an organic substrate. Semi-empirical molecular orbital calculations suggest that the nano-ZnS-catalyzed photooxidation should be predictable from energetics in the formation of the α-carbon radicals through one-hole oxidation and deprotonation, and from change in the bond order of αC–H bond of the α-carbon cation radicals.
Kinetics of Oxygen Exchange between Arsenic Acid and Solvent Water
Authors: Okumura Akiko , Matsumiya Yuko , Yamamoto Kasumi , Ueno Reiko , Suzuki Mariko , Yamabe Shinichi 
Published: July 2006

Abstract
The rates (R) of the oxygen exchange of arsenic acid with solvent water were measured over a wide range of hydrogen-ion concentrations. At pH &gt; 4, a 18O tracer method was used ([As(V)] = 0.07 mol dm−3, 0—50 °C). At pH &lt; 5, 17O NMR line broadening technique was used ([As(V)] = 1 mol dm−3, 50—90 °C). Over the whole pH range studied, the variation of R amounts to 1010, and the comprehensive rate law is expressed as: R = k11h[H+][H3AsO4] + k11[H3AsO4] + k12[H2AsO4−] + k13[HAsO42−] + k14[AsO43−] + k21[H3AsO4]2 + k22[H3AsO4][H2AsO4−] + k23[H2AsO4−]2 + k24[H2AsO4−][HAsO42−] + k25[HAsO42−]2. The rate constant for each elementary process in the equation was obtained. The activation parameters of each elementary process were evaluated. The oxygen exchange rate of arsenic acid was compared with that of phosphoric acid. The contrast of an SN2-type exchange of the former acid vs. an SN1-type one of the latter is suggested.
Effect of Sonolysis on Acid Degradation of Chitin to Form Oligosaccharides
Authors: Takahashi Yasuko , Miki Fumie , Nagase Kazuko 
Published: July 2006

Abstract
Chitin [partially deacetylated β-(1→4)-linked 2-acetamide-2-deoxy-β-d-glucopyranose, (GlcNAc)n] was hydrolyzed by hydrochloric acid under the ultrasound irradiation. The first seven members of (GlcNAc)n in the degradation fluid were analyzed with high performance liquid chromatography (HPLC). The produced amounts of (GlcNAc)1—7 obtained by the degradation in concd HCl increased almost in proportion to the degradation time up to 120 min when sonolysis was used concomitantly. The yield of saccharides in the degradation fluid by concd HCl with sonolysis was about 2—4 times as much as that in the hydrolysis without sonolysis. The yield(%) increased with increasing of the concentration of HCl (6—12 mol dm−3) but decreased with increase of the concentration of chitin, showing a solvent volume effect. For the production of higher oligosaccharides, such as (GlcNAc)5—7, degradation with sonolysis for not longer than two hours is desirable. Deacetylated products were negligible. The effect of sonolysis is discussed from the aspect of the interactions of water with saccharide chains.
Molecular Reorientation in AlBr3·NH3, as Studied by the 81Br Nuclear Quadrupole Resonance
Authors: Ishihara Hideta , Yamada Koji , Okuda Tsutomu , Weiss Alarich 
Published: July 2006

Abstract
The temperature dependence of the 81Br nuclear quadrupole resonance (NQR) frequencies and spin-lattice relaxation times (T1Q) of 81Br NQR have been measured in aluminum tribromide–ammonia (1/1), AlBr3·NH3, crystals. The 81Br NQR spectrum consists of 6 lines, which are ascribed to two AlBr3 groups. This has been confirmed by the observation of 27Al NQR using the 81Br ↔ 27Al spin echo double resonance method. A 81Br T1Q measurement revealed that the activation energies for the reorientation of the AlBr3 groups or the molecular tumbling of AlBr3·NH3 are 61.1 and 81.6 kJ mol−1. The difference in the activation energies was reflected in the temperatures of the fade-out of the 81Br NQR lines at Tf = 320 and 350 K, respectively.
N,N-Dimethylformamide + 2-Methoxyethanol Binary Mixtures. Viscosity and Activation Energy of Viscous Flow at Various Temperatures
Authors: Corradini Fulvio , Franchini GianCarlo , Marchetti Andrea , Tagliazucchi Mara , Tassi Lorenzo 
Published: July 2006

Abstract
Dynamic viscosity (η) of binary solvent mixtures of N,N-dimethylformamide (DMF, component 1) + 2-methoxyethanol (ME, component 2) has been investigated at 19 temperatures ranging from −10 to +80 °C. Some empirical equations have been applied in order to establish the best regression fitting procedures η = η(T), η = η(X1) and η = η(T, X1). For this binary solvent system, the viscometric properties are continuous but not linear functions of the mixture composition. Therefore, experimental η values were used to calculate the excess viscosities (ηE) and excess Gibbs activation energies (ΔG*E) of viscous flow. Both these quantities strongly deviate from ideality over the whole composition range of the investigated mixtures. Furthermore, deviations from the ideal behaviour could be very useful in order to evidentiate the formation of solvent–cosolvent complex species and to evaluate their stoichiometrical composition.
Formation of the Oxanickelacyclopentene Complex from Nickel(0), Carbon Dioxide, and Alkyne. An ab initio MO/SD-CI Study. Part II. Reactivity and Regioselectivity of Hydroxyacetylene
Authors: Sakaki Shigeyoshi , Mine Kazuya , Hamada Taisuke , Arai Toru 
Published: July 2006

Abstract
The formation reaction of oxanickelacyclopentene from [Ni(PH3)], hydroxyacetylene (a model of ethoxyacetylene), and carbon dioxide was investigated by the ab initio MO/SD-CI method. Of the two possible products of oxanickelacyclopentene and , the former was yielded with a lower activation energy (Ea) of 27 kcal mol−1 and a higher exothermicity (Eexo) of 31 kcal mol−1 than the latter (Ea = 38 kcal mol−1 and Eexo = 25 kcal mol−1). This result is consistent with the regioselectivity experimentally observed in the Ni(0)-catalyzed 2-pyrone synthesis from ethoxyacetylene and carbon dioxide. The regioselectivity of this reaction and the reactivity of hydroxyacetylene are discussed in terms of the energy level and the shape of the hydroxyacetylene π* orbital.
Kinetics of Electrochemical Reduction of Carbon Dioxide on a Gold Electrode in Phosphate Buffer Solutions
Authors: Noda Hidetomo , Ikeda Shoichiro , Yamamoto Akio , Einaga Hisahiko , Ito Kaname 
Published: July 2006

Abstract
The kinetics of the CO formation by electrochemical reduction of carbon dioxide on a gold electrode investigated in a series of potassium phosphate buffer solutions. CO is the principal product under the above condition. Small amounts of hydrocarbons, such as CH4, C2H4, and C2H6, are detected in the solutions of pH 5.2, 6.2, and 6.8. The Tafel slopes of the partial current density for the CO formation, ICO, at different pH are all ca. −120 mV/decade. The reaction mechanism has been proposed on the basis of the relationships between ICO and the electrode potential and between ICO and the reaction order with respect to CO2, which is ca. 1.
IR Investigation of Selective Reduction of NO by Ethene on Cu-ZSM-5
Authors: Tabata Takeshi , Ohtsuka Hirofumi , Kokitsu Mikako , Okada Osamu 
Published: July 2006

Abstract
Adsorbed species during the reaction of selective catalytic reduction of NOx by hydrocarbons (HC-SCR) on Cu ion-exchanged ZSM-5 (Cu-ZSM-5) were investigated by in situ FT-IR using isotopes as well as gas phase analysis. No oxygen-containing species was observed by IR and no reaction proceeded in the presence of gaseous O2 and C2H4 below 473 K, at which HC-SCR occurs. However, an extra NOx species (tentatively assigned to organic nitrite or nitrate species), other than inorganic NOx species derived from O2 and NO, appeared very rapidly in IR at 1670 cm−1 at room temperature, in the presence of adsorbed NO2 species, gaseous C2H4 and NO. Afterwards, a carbonyl species (1677 cm−1) was formed gradually at room temperature. When the extra NOx species was observed, N2 and N2O evolved even at room temperature, therefore, the extra NOx species is considered to be related to HC-SCR. In the O2 + C2H4 + NO reaction at 473 K, no nitrogen-containing species, except for quite a small amount of nitrile (2168 cm−1), was observed in IR. At 473 K, N2, and CO evolved very rapidly with a steep increase in the IR intensity of carboxylate (1574 and 1375 cm−1), while CO2 and carbonyl species increased more slowly.
Segmented Contractions of Gaussian Basis Sets for Relativistic Molecular Calculations
Authors: Watanabe Yoshihiro , Matsuoka Osamu 
Published: July 2006

Abstract
A method for segmented contractions of relativistic Gaussian basis sets is proposed, in which the large- and the small-component coefficients of the contracted basis sets are taken directly from the uncontracted relativistic basis sets and their kinetic balance is disregarded. The energy increases by this contraction scheme are found to be very small and the variational collapse does not occur. This method also reproduces very well the orbital energies and the radial expectation values of uncontracted basis sets. Examples of calculations on iodine (Z = 53), gold (Z = 79), and thorium (Z = 90) are reported in detail.
Micro Enzyme-Sensor with an Osmium Complex and Porous Carbon for Measuring Galactose
Authors: Miyata Kazuhisa , Fujiwara Masahiko , Motonaka Junko , Moriga Toshihiro , Nakabayashi Ichiro 
Published: July 2006

Abstract
A micro enzyme-sensor, based on galactose oxidase (EC 1.2.3.9) and a tris(2,2′-bipyridine) complex of osmium(II/III) as a redox mediator ([Os(bpy)3]2+/3+), fabricated on a carbon electrode (25 μm diameter), was developed for measuring galactose. To obtain the carbon electrode, a platinum-disk electrode (25 μm diameter) was etched in hot aqua regia to create a cavity (depth of ca. 3—5 μm) at its tip. A porous carbon material was prepared from 90% acetylene black and 10% Teflon emulsion as a binder, and then packed into the cavity of the platinum-disk electrode’s tip. The carbon electrode was immersed in the osmium complex with 0.1 mol dm−3 LiClO4 in order to adsorb it in the carbon pores, which was monitored based on an increase in the anodic peak current and the cathodic peak current based on the osmium complex redox potential by the cyclic voltammogram. The tip of the carbon electrode was dipped overnight in a buffer solution of pH 7.00 containing galactose oxidase so as to immobilize it on this surface by adsorption. The characteristics of the porous-carbon material surface by X-ray diffraction (XRD) and scanning electron microscopy (SEM), the calibration curve for measuring of galactose, and the effects of the pH, temperature and concomitant compounds were investigated. By the XRD measurement, the porous carbon after treating a Zonyl FSN fluoro-carbon surfactant solution, a 5% Nafion® solution with methanol, and an osmium complex with 0.1 mol dm−3 LiClO4 showed good crystallinity compared with carbon powder. The structure of the carbon-electrode surface was visually confirmed using SEM photographs. The carbon surface had many pores, and galactose oxidase existed on it after adsorption. Under the optimum conditions the amperometric response of this sensor was linear over concentration ranges of 0.01—5.00 mmol dm−3 galactose; the correlation coefficient was 0.999.
Synergistic Extraction of Rare Earths(III) with β-Diketone and Nitrogen-Containing Terdentate Ligand, 2,2′:6′,2″-Terpyridine
Authors: Satake Saeko , Tsukahara Satoshi , Suzuki Nobuo 
Published: July 2006

Abstract
The synergistic extraction of rare earth(III) ions (RE: La, Sm, Tb, and Lu) was investigated using a β-diketone (HA), i.e., trifluoroacetylacetone (Htfa) or hexafluoroacetylacetone (Hhfa), in the presence of a terdentate ligand, 2,2′:6′,2″-terpyridine (terpy) into benzene. The formation of complexes such as RE(A)2+ or RE(A)2+ in the aqueous phase was observed. The synergistic enhancement is attributed to the formation of an adduct RE(A)3terpy in the benzene phase. The adduct formation constants (βS,1) and the synergistic extraction constants were determined. For each RE(III), the βS,1 value in the Htfa–terpy system is smaller than that in the Hhfa–terpy system. The βS,1 values decrease with increasing atomic number of RE(III) in the Htfa–terpy system, but the βS,1 value for La(III) is smaller than that for the other RE(III) in the Hhfa–terpy system.
Mössbauer Emission Spectra of 119Sn in Binary Compounds of Antimony and Tellurium
Authors: Ambe Shizuko , Ambe Fumitoshi 
Published: July 2006

Abstract
The Mössbauer emission spectra of defect 119Sn atoms arising from 119Sb and 119mTe were measured in GaSb, InSb, In2Te3, ZnSb, CdSb, CdTe, and Ag2Te. The lattice sites of defect 119Sn atoms in these binary compounds were determined on the basis of the obtained Mössbauer parameters and the recoil energy associated with EC decays of the source nuclides. Together with the results of previous studies, the isomer shifts of both defect and normal 119Sn were shown to correlate with the electronegativitity of ligands in binary compounds of the main-group elements, such as Sn, Sb, and Te.
Kinetic Study of Interconversion between Two Geometrical Isomers of the Methoxy-Bridged Bis(silylene)iron Complex, (η-C5Me5)(OC)Fe{(SiMe2)···OMe···(SiMeOMe)}
Authors: Ueno Keiji , Ogino Hiroshi 
Published: July 2006

Abstract
Isomerization between two geometrical isomers of the methoxy-bridged bis(silylene)iron complex, anti-and syn-Cp*(OC)Fe{(SiMe2)···OMe···(SiMeOMe)} (Cp* = η5-C5Me5), was investigated by means of a variable-temperature 1H NMR experiment. The equilibrium constant (K) for the isomerization and its thermodynamic parameters were determined to be K = [syn-isomer]/[anti-isomer] = 0.53 at 293 K in toluene-d8, ΔG°298 = 1.5 ± 0.5 kJ mol−1, ΔH° = 3.8 ± 0.2 kJ mol−1, and ΔS° = 7.7 ± 1.0 J mol−1 K−1. Computer simulation of the VT spectra and calculation using Eyring equation yielded activation parameters, ΔH‡ = 83.8 ± 3.2 kJ mol−1, ΔS‡ = 42.3 ± 9.6 J mol−1 K−1, and ΔG‡298 = 71.2 ± 6.0 kJ mol−1, for the isomerization from the anti-isomer, in which the terminal OMe group is located on the opposite side of the Cp* group with respect to the Fe–Si–O(bridged)–Si ring, to the syn-isomer. A mechanism in which the bridging OMe group is replaced by the terminal OMe group is proposed for the isomerization.