bluuebunny/crossref_metadata_2025 huggingface dataset:
Coal Solubilization with Cadmium and Butyl Iodide under Mild Conditions
Authors: Yoneyama Yoshiharu , Nakayama Hiroaki , Nishi Hiroshi , Kato Tsutomu
Published: July 2006

Several coals were treated with Cd and butyl iodide at 130 °C under atmospheric pressure to obtain more detailed information concerning coal-solubilization for a metal–alkyl halide system under mild conditions. The treatment effectively converted coal to benzene-soluble products with an optimum yield of 57 wt%, somewhat less than that obtained in a Zn–butyl iodide system. There was no correlation between the rank of coal used and the benzene solubility. Reactions of model compounds were also carried out under similar conditions. Polynuclear aromatic compounds gave polybutyl-substituted and/or -addition derivatives. Although the alkyl ether linkages were easily cleaved, the aryl ether linkages were not. In addition, many butyl groups were introduced into both the aromatic and aliphatic moieties. These results suggest that the high benzene solubility is attained by an introduction of the many butyl groups, as well as cleavage of the alkyl ether linkages. Also, the introduction of butyl groups into the aliphatic moiety suggests smaller benzene solubilities of Cd-treated coal compared to those of Zn-treated coal. Because most of the products of the model compounds were similar to those obtained in the Zn–butyl iodide system, and some of the butyl groups introduced were rearranged to s-butyl, it is suggested that both alkyl cation reactions and alkyl radical reactions occur competitively in the Cd–butyl iodide system, as well as in the Zn–butyl iodide system.
Studies on n-CdSe/Ti Semiconductor Septum Based Photoelectrochemical Solar Cell in Regard to the Influence of Structural and Compositional Characteristics of the Semiconductor Electrode
Authors: Pandey Ram Nagina , Babu Kondapaneni S Chandra , Singh Dharam , Srivastava Onkar Nath
Published: July 2006

A new type of photoelectrochemical (PEC) solar cell based on semiconductor septum (SC-SEP) photoelectrode has been shown to yield higher electrical power output than the conventional PEC solar cell. In the present study, photoelectrochemical, structural and compositional characteristics of the semiconductor component in n-CdSe/Ti septum, based SC-SEP, PEC solar cell, employing some reversible electrolyte systems under prolonged PEC operation (100 h), revealed that the CdSe photoelectrode undergoes deterioration through ‘Cd’ loss. For example, in the case of the cell Pt, 1 M 3S//n-CdSe/Ti//0.1 M AgNO3 (1 M = 1 mol dm−3), Pt; CdSe showed loss of ‘Cd’. This resulted in decrease of the cell power output (from Vph and Isc of 1.42 V and 20 mA cm−2 to 1.3 V and 13 mA cm−2 respectively). It has been shown in the present investigation that the best way to arrest semiconductor deterioration was by adding 0.1 M Se to polysulfide electrolyte thereby stabilizing this efficient SC-SEP, PEC cell.
Absorption Spectra and Electrical Resistivities of Bis(1,2-dione dioximato)nickel(II) Complexes at High Pressures
Authors: Shirotani Ichimin , Suzuki Kazunaga , Suzuki Toshihiro , Yagi Takehiko , Tanaka Masashi
Published: July 2006

The absorption spectra of [Ni(dmg)2], [Ni(niox)2], [Ni(dpg)2], and [Ni(bqd)2] were studied at various pressures. Two characteristic absorption bands, the metal-to-ligand charge-transfer (M–L) and the 3d–4p bands, were observed in the visible region for these complexes. The interesting spectral features observed under high pressures were: (1) The excitations shift remarkably to lower energies with increasing pressure. (2) The rates of the peak shifts for the d–p and M–L bands increase in the order [Ni(niox)2] < [Ni(dmg)2] < [Ni(dpg)2]. (3) The peak shifts of the M–L bands are much smaller than those of the d–p bands. (4) The absorption intensity of the M–L band of [Ni(niox)2] decreases rapidly above 10 GPa, and the band is hardly observed at around 14 GPa. (5) A new absorption band in [Ni(dpg)2] exists above about 3 GPa. The electrical resistivity of [Ni(dmg)2], [Ni(niox)2], and [Ni(dpg)2] has been studied under high pressures. These complexes are insulators with a resistivity of 1015 Ω cm at atmospheric pressure. The resistivities at around 23 GPa were 50 Ω cm for [Ni(dmg)2], 7 × 105 Ω cm for [Ni(niox)2] and 2 × 103 Ω cm for [Ni(dpg)2].
Dye–Surfactant Interaction in Submicellar Concentration Range
Authors: Dutta Robin Kumar , Bhat Subray Narayan
Published: July 2006

Interactions of cationic dyes, viz., phenosafranine (PSF), safranine O (SFO) and safranine T (SFT) with anionic surfactants, viz., sodium dodecyl sulfate (SDS) and sodium octyl sulfate (SOS) in submicellar concentration ranges have been investigated spectroscopically. The interaction has been shown to be an induced protonation of the dye in the dye–surfactant ion pair. Even though the opposite charges on the dye and the surfactant are the primary requirements for the ion pair formation, it is the hydrophobicity of the surfactant as well as of the dye which induces the protonation. The spectroscopic and thermodynamic parameters show that the orders of effectiveness of the dyes and the surfactants for the interaction are, SFO > SFT > PSF and SDS >> SOS.
Kinetics and Mechanism of Oxidation of Ethyl Phenylthioacetates by Bromamine-B
Authors: Gurumurthy Rajagopal , Sathiyanarayanan Kulathu Iyer , Gopalakrishnan Mannathusamy
Published: July 2006

The kinetics of oxidation of several substituted ethyl phenylthioacetates by bromamine-B (sodium salt of N-bromobenzenesulfonamide) has been studied in 50% (v/v) aqueous ethanol medium. Disodium hydrogenphosphate and sodium dihydrogenphosphate buffer has been used. The reaction is of a total second order, first order each with respect to the reactants. A catalytic effect of mercury has been observed and the order with respect to Hg(II) is one. Electron-releasing substituents generally accelerate the rate while electron-withdrawing groups retard the rate. A good correlation is found to exist between log k2 and Hammett σ constants. Two mechanisms have been proposed, one in presence of Hg(II) and the other in the absence of Hg(II). In presence of Hg(II), rate = k[C1][H2OBr]+ and in the absence of Hg(II), rate = k[S] [H2OBr]+

Susceptibility of the reaction to the steric effect of ortho substituents, has been analyzed in the light of application of Taft’s steric energy relationships.
Lithium Alkylamide-Catalyzed Addition Reaction of Alkylamines to Vinyl Monomers. III. Addition Reaction of p-Substituted Benzylamines to Styrene and Divinylbenzenes
Authors: Hamana Hiroshi , Iwasaki Fuminori , Nagashima Hiroyoshi , Hattori Kazuhisa , Hagiwara Tokio , Narita Tadashi
Published: July 2006

The lithium alkylamide-catalyzed addition reaction of p-substituted benzylamines with m- and p-divinylbenzene was examined in order to synthesize new styrene derivatives. Though divinylbenzene possesses two vinyl groups, 1 : 1 adducts, the N-(p-substituted benzyl)vinylphenethylamines (6, 8) were found to be prepared selectively. The reaction with styrene was also examined as a model reaction. From kinetic studies, the Hammett p values for the addition reaction of p-substituted benzylamines to the styrene, m-divinylbenzene and p-divinylbenzene, were −0.72, −0.67, and −1.1, respectively, at 50 °C.
New Cholestane Bisdesmosides from the Bulbs of Ornithogalum thyrsoides
Authors: Kubo Satoshi , Mimaki Yoshihiro , Sashida Yutaka , Nikaido Tamotsu , Ohmoto Taichi
Published: July 2006

Four new cholestane bisdesmosides have been isolated from the fresh bulbs of Ornithogalum thyrsoides. Their structures were determined by spectroscopic analysis and chemical evidence to be (22S)-5α-cholestane-1β,3β,16β,22-tetrol 1-O-α-l-rhamnopyranoside 16-O-β-d-glucopyranoside (1), (22S)-5α-cholestane-1β,3β,16β,22-tetrol 1-O-α-l-rhamnopyranoside 16-O-(6-O-acetyl-β-d-glucopyranoside) (2), (22S)-5α-cholest-24-ene-1β,3β,16β,22-tetrol 1-O-α-l-rhamnopyranoside 16-O-β-d-glucopyranoside (3), and (22S)-5α-cholest-24-ene-1β,3β,16β,22-tetrol 1-O-α-l-rhamnopyranoside 16-O-(6-O-acetyl-β-d-glucopyranoside) (4), respectively. An advanced Mosher’s method was applied to determine the C-22 absolute configuration. Compound 4 showed inhibitory activity on cyclic AMP phosphodiesterase.
Kinetics and Mechanism of Osmium(VIII) Catalyzed Oxidation of Uric Acid with N-Chloro-p-toluenesulfonamide (Chloramine-T) in Alkaline Medium
Authors: Sharma Nidhi , Mishra Som Kant , Sharma Prem Dutt
Published: July 2006

The kinetics of oxidation of uric acid (UaH2) by chloramine-T (CAT) studied in the presence of osmium(VIII) in alkaline medium conform to a rate law (i)

where K2 and K3 are second dissociation constant of uric acid and formation constant of an intermediate complex respectively. Osmium(VIII) catalyzes the reaction intramolecularly via redox cycle of Os(VIII)/Os(VI).
Zinc Bismuthate Zn(BiO3)2. I. A Useful Oxidizing Agent for the Efficient Oxidation of Organic Compounds
Authors: Firouzabadi Habib , Mohammadpour-Baltork Iraj
Published: July 2006

Zinc bismuthate is an easily prepared and a stable compound. It could be used as an oxidant in organic solvents under aprotic or in the presence of a catalytic amount of a protic solvent. Primary and secondary saturated, allylic, and benzylic alcohols are converted to their carbonyl compounds in high yields. Mildness of the reagent is shown by the oxidation of thiols to their disulfides in excellent yields. Thioethers are also oxidized to their corresponding sulfoxides in good yields.
Structure and Orientation of o-Phenylene Phosphorochloridite and o-Phenylene Phosphorochloridate Dissolved in a Nematic Phase
Authors: Saito Koji , Yoshino Akihiro , Yoshida Tadayoshi , Takahashi Kensuke
Published: July 2006

The 1H and 31P NMR spectra of the title compounds dissolved in a nematic phase of N-(p-ethoxybenzylidene)-p-butylaniline (EBBA) were analyzed, and the structures of the proton and phosphorus skeleton determined.
Effects of Surface Pretreatments of a Glass Substrate on the Properties of Tin Oxide Film Prepared by Plasma-Assisted Chemical Vapor Deposition
Authors: Arai Masahiko , Hamada Satoshi , Nishiyama Yoshiyuki
Published: July 2006

A glass substrate was modified by thermal and chemical treatments with a fluoride solution and molten potassium salt. These surface treatments were found to affect both the electroconductive and optical properties of tin oxide film prepared by plasma-assisted chemical vapor deposition.
Magnetic Properties of Pyro-Carbons Prepared from Poly(vinyl chloride) and Activated Carbon
Authors: Murata Kazuhisa , Ushijima Hirobumi , Ueda Hisashi , Kawaguchi Kenji
Published: July 2006

The magnetic properties of pyro-carbons prepared from poly(vinyl chloride) and activated carbon were examined. In contrast with the observation of a hysteresis from vibrating sample magnetometer measurement, the ESR spectra showed only an usual Δms = ±1 signal. The temperature dependence of the magnetic susceptibility approximately obeys Curie’s law: The estimated spin density is ca. 1019 spins/g, roughly close to that calculated from ESR method. Therefore, it seems likely that the bulk magnetic nature of PVC/C sample is still paramagnetic, although there is a possibility that local microregions having anomalous high spin character could be formed in the sample.
Orientation of the Addition of Dimethyl Phosphonate to 5,6-Dideoxy-6-nitro-d-hex-5-enofuranoses
Authors: Hanaya Tadashi , Yamamoto Hiroshi , Yamamoto Hiroshi
Published: July 2006

The addition of dimethyl phosphonate to six 5,6-dideoxy-6-nitro-d-hex-5-enofuranoses at 25 °C in the presence of triethylamine preponderantly gave (5R)-adducts, whereas the same reaction at 100 °C without a base yielded (5S)-adducts as the main products.
First Synthesis and Deodorant Activities of Compounds Isolated from Thyme (Thymus Vulgaris L.) and Their Analogues
Authors: Miura Yozo , Yamaguchi Fumihiko , Ogo Yoshiaki
Published: July 2006

4-(4-Hydroxy-5-isopropyl-2-methylphenyl)-6-isopropyl-3-methyl-3,5-cyclohexadiene-1,2-dione and 5,5′-diisopropyl-2,2′-dimethyl-3,4,4′-biphenyltriol, isolated from thyme, and their analogues, 4-(2,5-dimethyl-4-hydroxyphenyl)-3,6-dimethyl-3,5-cyclohexadiene-1,2-dione and 2,2′,5,5′-tetramethylbiphenyl-3,4,4′-triol, have been synthesized and their deodorant activities against methanethiol measured.
Hydrogenation and Isomerization of Disodium Maleate in the Solid Phase over Fine Nickel Powder
Authors: Harada Tadao , Osawa Tsutomu
Published: July 2006

Disodium maleate was converted to a mixture of disodium maleate, fumarate, and succinate in the solid phase when particles of the starting material were kept in contact with fine nickel powder pretreated with hydrogen gas at 200 °C.
A Precise Calorimetric Study of 18-Crown-6 Complexes with Sodium, Potassium, Rubidium, Caesium, and Ammonium Ions in Aqueous Solution
Authors: Ozutsumi Kazuhiko , Ishiguro Shin-ichi
Published: July 2006

The complexation of 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6) with sodium, potassium, rubidium, caesium, and ammonium ions has been studied by precise titration calorimetry in aqueous solution containing 0.1 mol dm−3 (C2H5)4NCl as a constant ionic medium at 25 °C. The calorimetric data were well explained in terms of the formation of the [M(18-crown-6)]+ (M = Na+, K+, Rb+, Cs+, and NH4+) complexes, and their formation constants, enthalpies, and entropies were determined. The thermodynamic parameters of the complexes thus obtained are discussed in relation to their structures in solution.
7-Epidenticulatolide, a New Cembranolide with a Cyclic Peroxide Function from the Soft Coral Lobophytum denticulatum
Authors: Uchio Yasuto , Eguchi Shizuko , Fukazawa Yoshimasa , Kodama Mitsuaki
Published: July 2006

A new cembranolide diterpene, 7-epidenticulatolide, was isolated from a soft coral, Lobophytum denticulatum. The structute was deduced spectroscopically and determined by X-ray crystallography.
Reaction of Cyclic Polysulfides. Oxidation of 6b,9a-Dihydroacenaphtho[1,2-d][1,2,3]trithiole
Authors: Satoh Shin-ichi , Sato Ryu
Published: July 2006

The treatment of 6b,9a-dihydroacenaphtho[1,2-d][1,2,3]trithiole with 1 equiv of m-chloroperbenzoic acid (mCPBA) affords the corresponding oxidized product, 6b,9a-dihydroacenaphtho[1,2-d][1,2,3]trithiole 7-oxide, as the sole product in 88% yield, whereas the oxidation using N-halosuccinimide gives 6b,9a-dihydroacenaphtho[1,2-d][1,2,3]trithiole 7,7-dioxide via 6b,9a-dihydroacenaphtho[1,2-d][1,2,3]trithiole 7-oxide. Moreover, the reaction with chloramine T gives a 1,3,2-dithiazolidine derivative in satisfactory yield.
DDQ Oxidation of 6- or 8-Allyl-7-hydroxycoumarins. A New Synthesis of Benzodipyrandiones and Furobenzopyranones
Authors: Prashant Avula , Krupadanam Gazula Levi David , Srimannarayana Gutety
Published: July 2006

A novel synthesis of 2H,8H-benzo[1,2-b:3,4-b′]dipyran-2,8-diones, 2H,8H-benzo[1,2-b:5,4-b′]dipyran-2,8-diones, 2H-furo[2,3-h][1]benzopyran-2-ones, and 7H-furo[3,2-g][1]benzopyran-7-ones was achieved by developing 2-pyrone and furan ring over coumarin. 6- or 8-Ally-7-hydroxycoumarins on oxidation with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) afforded benzodipyrandiones and furobenzopyranones. The structures of the compounds now synthesized were established by analytical, spectral, and comparison with authentic samples prepared by the known procedures.
1H NMR Peak Assignment of 1-Aryl-3-methoxy-3-methyltriazenes
Authors: Wilman Derry E V
Published: July 2006

No Abstract
A Comment on the Vibrational Assignment of the CN(4II) in “Pressure-Dependent Intensity Anomalies in the B2Σ+∼4II Perturbed Rotational Lines of the CN(B2Σ+–X2Σ+) 14-14 Band”
Authors: Kanda Kazuhiro , Ito Haruhiko , Suzuki Kaoru , Kondow Tamotsu , Kuchitsu Kozo
Published: July 2006

No Abstract
Unique Molecular Structures of Tungsten Phenoxides
Authors: Kanehisa Nobuko , Kai Yasushi , Kasai Nobutami , Yasuda Hajime , Nakayama Yuushou , Nakamura Akira
Published: July 2006

As a series of structural chemistry of early transition metal-phenoxides, the molecular structures of WCl5[2,6-(CH3)2C6H3O] (1) and WCl4[2,6-(CH3)2C6H3O]2 (2) have been determined by an X-ray diffraction method. Crystal data: 1; orthorhombic, space group Cmcm, a = 7.979 (3), b = 17.094 (4), c = 12.536 (2) Å, V = 1709.7 (8) Å3, Z = 4, Dc = 2.412 g cm−3, 2; monoclinic, space group C2/m, a = 17.615 (4), b = 7.188 (2), c = 8.396 (2) Å, β = 119.93 (2)°, V = 921.3 (4) Å3, Z = 2, Dc = 2.047 g cm−3. Complexes 1 and 2 have a molecular symmetry of C2v (mm) and C2h (2/m), respectively; the W–O–C(phenoxy) angles are 180° in 1 and 179° in 2. These are the first examples with a straight W–O–C(phenoxy) bond. By retrieval from the Cambridge Crystallographic Database the W–O–C(phenoxy) angles have been revealed to cover a wide range of 117–180°, which correlated with the W–O distance in the hyperbolic mode.
Kinetic Study in Aqueous Solutions of Alcohols with Butyl Group by Ultrasonic Methods
Authors: Nishikawa Sadakatsu , Ueda Masayuki
Published: July 2006

The ultrasonic absorption coefficients in aqueous solutions of 3-methoxy-1-butanol and 1-methoxy-2-butanol have been measured in the frequency range from 8.5 to 220 MHz at 25 °C. One process associated with a single-relaxational ultrasonic absorption has been found in both solutions. From the concentration dependencies of the relaxation frequency and the amplitude of ultrasonic relaxation, the cause of the relaxation has been attributed to a perturbation of an equilibrium associated with interaction between the solute and the solvent. The rate and thermodynamic parameters have been determined for the reaction and the effect of the isomeric alcohols on water structure has been considered based on these parameters. As results, both alcohols have been found to act as a water structure promoter. The effect of the methoxyl group in the alcohol molecules on the water structure has been speculated to break the water hydrogen bonds, i.e. to act as a structure breaker for water. Also, the results for solutions of other isomers, 2-propoxyethanol and 3-ethoxy-1-propanol, and that of a similar structure, 2-allyloxyethanol, have been compared with those obtained in this study. The effects of substituents in alcohol molecules have been discussed in relation to the water structure. They have also been considered from a comparison with the hydrophobic ability of the alcohols estimated from the concentration dependence of the apparent molar compressibility, along with the result from an ethanol aqueous solution. Both estimations from ultrasonic absorption and compressibility have provided a consistent interpretation for the effects on the water structure. From these present results regarding ultrasonic absorption, it has been speculated that the large ultrasonic absorptions observed near critical points in some alcohol solutions are superimposed with the usual Debye type relaxations.
Mechanochemical Reaction of Calcium Alginate Hydrogel due to a Counterion Exchange
Authors: Baba Kazuhiko , Yonese Masakatsu , Kishimoto Hiroshi
Published: July 2006

Stress relaxations of calcium alginate hydrogel (CaAlg gel) rods induced by adding other counterions were investigated by measuring their tensile stresses. The stress decreased upon adding Ba2+ and H+, whereas it increased upon adding Pb2+. The relaxation time, equilibrium elastic modulus and spontaneous elastic modulus were obtained. The relaxation times were analyzed using a theory involving counterion diffusion accompanied by an ion-exchange reaction under the assumption that the rate-determing step is the diffusion of added counterions (M2+ and M+) in the gel. The relaxation time was found to be a function of the concentration and diffusivity of the added counterions, the radius of the gel rod, the concentration of carboxylate ions and the counterion-selectivity coefficient () of the alginate. By fitting the observed relaxation times with theoretical ones, the optimal values of a were obtained: = 100, = 20 and = 3 × 103. The rate-determing step of stree relaxation was confirmed to be the counterion diffusion process in CaAlg gel.
Crystal Structures and Magnetic Properties of Novel μ-Carboxylato-μ-Hydroxo-Bridged Binuclear Copper(II) Complexes with 1,10-Phenanthroline
Authors: Tokii Tadashi , Hamamura Naohiko , Nakashima Michio , Muto Yoneichiro
Published: July 2006

Novel μ-carboxylato-μ-hydroxo-bridged binuclear copper(II) complexes with 1,10-phenanthroline, [Cu2(OH)(RCOO)(phen)2]X2·H2O (where R = H, X = BF4 (1); R = CH3, X = NO3 (2); R = C2H5, X = NO3 (3)) were prepared and characterized by elemental analyses, electronic spectra, magnetic susceptibilities, and X-ray structure analysis. The magnetic susceptibility data conform to the usual dimer equation. The −2J values are −109 cm−1 for 1, −111 cm−1 for 2, and −109 cm−1 for 3, indicating that a strong ferromagnetic spin coupling exists in these complexes. The crystal structures of 2 and 3 were determined by the single-crystal X-ray diffraction method. The crystallographic data are: Compound 2, monoclinic, P21/n, a = 8.107 (10), b = 18.554 (9), c = 18.616 (7) Å, β = 99.14 (6)°, V = 2765 (6) Å3, Z = 4, R = 0.045 for 3274 observed unique reflections; compound 3, monoclinic, P21/n, a = 7.981 (10), b = 18.352 (8), c = 19.247 (8) Å, β = 97.98 (7)°, V = 2792 (4) Å3, Z = 4, R = 0.047 for 3220 reflections. These complexes have very novel roof-shaped binuclear units with dihedral angles (122.8° for 2 and 122.7 ° for 3) observed between two basal planes of CuO2N2. These small dihedral angles are mainly attributed to the strong ferromagnetic exchange interaction in the present complexes.
Preparation, Stereochemistry, and Kinetics of Isomerization and Racemization of Bis(2,2′-bipyridine N,N′-dioxide)chromium(III) Complexes Containing an Oxalate or Malonate Ion
Authors: Kanno Hideaki , Tomita Masanori , Utsuno Shunji , Fujita Junnosuke
Published: July 2006

Two new chromium(III) complexes of the type, [Cr(L)(bpdo)2]+ (L = oxalate (ox2−) or malonate (mal2−) ion), where bpdo denotes 2,2′-bipyridine N,N′-dioxide, were prepared and resolved into a pair of enantiomers by use of Ag2[Sb2{(+)589-tartrate}2]. The perchlorates of these complexes were found to crystallize in the lel2 (Δ(λλ), Λ(δδ)) form. Upon dissolution in water, the complexes isomerized to the lel·ob (Δ(λδ), Λ(δλ)) form with a rapid change in absorption spectra, and then racemized (Δ Λ). Rates of the isomerization and racemization at 25 °C were 7.65 × 10−3 s−1 and 2.20 × 10−3 s−1, respectively for the ox complex, and 4.95 × 10−3 s−1 and 6.42 × 10−5 s−1 for the mal one. These rates were independent of concentrations of H+ and the free bpdo ligand, indicating an intramolecular mechanism for these reactions. The faster reactions of the ox complex than those of the mal one may be attributed to the steric effect due to the less crowded structure of the ox complex.
Regioselective Hydrogenation of Unsaturated Compounds Using Platinum–Zeolite Coupled with Organosilicon Alkoxide by CVD Method
Authors: Kuno Hideyuki , Shibagaki Makoto , Takahashi Kyoko , Honda Ichiro , Matsushita Hajime
Published: July 2006

The regioselective hydrogenation of unsaturated compounds was carried out by catalysis with platinum-zeolite coupled with an organosilicon alkoxide using a chemical vapor deposition method (CVD-modified catalyst). In hydrogenation of a mixture of 1-nonene and trans-4-nonene by this catalyst, the reaction rate of 1-nonene was much greater than that of trans-4-nonene. In particular, when diphenyldiethoxysilane was used as the coupling reagent on the platinum–zeolite, excellent selectivity was produced. Further, it was elucidated that the terminal carbon–carbon double bonds are preferentially hydrogenated in the case of some compounds possessing more than one carbon–carbon double bond.
Photochromism of Heterocyclic Fulgides
Authors: Tomoda Akihiko , Kaneko Akira , Tsuboi Hideki , Matsushima Ryouka
Published: July 2006

Aiming at practical uses of photochromic compounds as data-storage media, electron-donating (e.g. p-dimethylaminophenyl) and conjugate chain (e.g. p-dimethylaminostyryl) substituted heterocyclic fulgides, e.g. 2-[1-(2-substituted 5-methyl-4-oxazolyl)ethylidene]-3-isopropylidenesuccinic anhydride and 2-[1-(5-substituted 2-methyl-3-thienyl)ethylidene or methlyene]-3-isopropylidenesuccinic anhydride, were prepared. The effect on photochromic performance was also investigated; it was clarified that substituents had effects on the red-shift and a significant increase in the color intensity of a colored form. However, the rate of the discoloration reaction was also affected, depressed, by the substituent.
1 : 1 Adduct Ion Formation of Simple Carbohydrate Derivatives with Cations Using FAB Mass Spectrometry. Comparison of O-Acetyl, N-Butyl, and O-Methyl Modifications
Authors: Sawada Masami , Shizuma Motohiro , Takai Yoshio , Yamada Hitoshi , Tanaka Takanori , Okumura Yasuo , Hidaka Yukio , Hanafusa Terukiyo , Takahashi Shigetoshi
Published: July 2006

The 1 : 1 adduct ion formation between a series of per-O-acetylated aldopyranoses (family 1) or N-butylated glycosylamines (family 2) and an organic/metallic cation (n-C8H17NH3+/K+ or Li+) has been examined using quantitative FAB mass Spectrometry. The per-O-acetyl modifications dramatically lead to negated selectivity of the carbohydrates toward the cation which has been clearly observed in per-O-methyl modifications. On the other hand, the mono-N-butyl modifications provide a similar selectivity pattern to mono-O-methyl ones. These results are understood on the basis of electronic and structural considerations.
Hydrosilylation of 1,4-Bis(trimethylsilyl)butadiyne and Silyl-Substituted Butenynes
Authors: Kusumoto Tetsuo , Ando Kenji , Hiyama Tamejiro
Published: July 2006

Hydrosilylation of 1,4-bis(trimethylsilyl)butadiyne using various hydridosilanes and Pt(IV), Pt(0), Rh(I) or Pd catalyst gave, depending on catalyst and hydridosilane, 1,1,3,4-tetrasilyl-substituted 1,3-butadienes or 1,1,3,4-tetrasilyl-substitued 1,2-butadienes. Formation of the 1,2-butadienes was proved to be attributable to second hydrosilylation of primary products 1,2,4-trisilyl-1-buten-3-ynes. For the second hydrosilylation a mechanism was proposed that involves silylmetalation induced through a metalacyclopropene intermediate.
Electric Field Orientation of Ionizable Polymers with Three Different Electric Dipole Moments. I. New Orientation Function and the Steady-State Electric Birefringence of Poly(l-α-glutamic acid) in Methanolic and Aqueous Solutions
Authors: Yamaoka Kiwamu , Kimura Manabu , Okada Mutsuo
Published: July 2006

In order to explain the field strength dependence of the steady-state electric birefringence of ionized poly(l-α-glutamic acid), (Glu)n, in solutions, a new orientation function, Φ(β,ρs,ρ,γ′), was derived on the basis of the permanent dipole, saturable and unsaturable induced dipole (PD–SUSID) moment mechanism. This concept of field orientation is new in that the induced electric moment consists of two parts: One is the saturable induced moment (ΔσE), which transforms to the permanentlike moment (ΔσE0) at the critical field (E0), and the other is the unsaturable induced moment (Δα′E) at any electric fields (E). Some novel features of Φ(β,ρs,ρ,γ′), were graphically illustrated. Comparisons were made between theoretical curves and the birefringence data experimentally measured at 20 °C up to 24 kV cm−1 for helical (Glu)n in pure methanol and in methanol–water (95 : 5 vol%) as well as for coiled (Glu)n in aqueous solutions (pH 6.9 and 8.0). The degree of dissociation was 0.041 in the former solutions and close to unity in the latter solutions. The field orientation was found to be mostly due to the permanent moment for unionized or slightly ionized (Glu)n, but dominantly due to the saturable induced moment for fully ionized (Glu)n. Appropriate procedures are discussed for estimating the intrinsic birefringence at infinitely high fields.
X-Ray Photoelectron Study of the Methane Interaction with LaCoO3
Authors: Tabata Kenji , Kohiki Shigemi
Published: July 2006

The interaction of CH4 with LaCoO3 has been studied at room temperature with the use of an X-ray photoelectron spectroscopy (XPS) analyzer. CH4 dissociated on the surface of LaCoO3, and new carbonaceous products were detected at 104 langmuir exposure on the spectra for C1s. Since the intensities of the adsorbed oxygen on the spectra for O1s gradually decreased in proportion to the increase in the amount of CH4 exposure, methane reacted with adsorbed oxygen of LaCoO3 at room temperature in an XPS analyzer.
Studies on Nickel-Containing Ziegler-Type Catalysts. I. New Catalysts for High-cis-1,4-polybutadiene
Authors: Sato Hiroshi , Yagi Yoshiharu
Published: July 2006

Some organic halogenides were found to induce a catalytic activity in a nickel naphthenate (Ni(naph)2)/AlEt3 system for the stereospecific polymerization of butadiene to a high cis-1,4 microstructure. These new activators were fluorinated carbonyl (or carboxyl) compounds, halogenated phenols or halogenated hydroquinones. These compounds were assumed to induce polymerization activity through the formation of Lewis acidic components with AlEt3. For this catalyst, H2O acted as an efficient molecular weight promoter.

(Trifluoromethyl)benzene was found to promote the activity of a catalytic system: Ni(naph)2/AlEt3/organic halides. AlEt2F was found to be formed between AlEt3 and (trifluoromethyl)benzene. Finally, a simple system was found to be an efficient catalyst, Ni(naph)2/AlEt2F/H2O, for which chlorinated phenols acted as an effective molecular weight regulator.
Studies on Nickel-Containing Ziegler-Type Catalysts. II. Low Molecular Weight (Liquid) Poly(diene)s with 1,4-Microstructure
Authors: Sato Hiroshi , Yasui Seimei
Published: July 2006

Liquid polybutadiene and liquid polyisoprene, which are usefull precursor for coatings, plastisizers or lubricants, were effectively synthesized by polymerizing butadiene and isoprene, respectively, in the presense of a nickel-containing Ziegler-type catalyst utilizing a lower α-olefin or molecular hydrogen as a molecular weight regulator. The catalyst consists of four components; nickel naphthenate (Ni(naph)2)/AlEt3/(trichloromethyl)benzene(BTC)/triphenyl phosphite (TPP) or triphenylphosphine (TPN). The microstructure of these liquid polymers is mainly 1,4-(cis/trans), which is advantageous for their reactivity and the rheological properties. The hydrogenated low molecular weight liquid polyisoprene exhibited very similar properties to those of squalane, which is a hydrogenated product of natural squalene.
Kinetics of Electroless Copper Plating in the Presence of Excess Triethanolamine
Authors: Kondo Koji , Ishida Nobumasa , Ishikawa Junji , Irie Masahiro
Published: July 2006

The electroless copper plating rate dependence on the various ligands, such as ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), N,N,N′,N′-tetrakis(2-hydroxypropyl)-ethylenediamine (HPA), N,N,N′,N′-tetrakis(2-hydroxyethyl)-ethylenediamine (HEA), triethanolamine (TEA), and triisopropanolamine (TIPA), were examined. TEA solution plating rate was the fastest of all ligands, the maximum rate being over 20 times faster than the current rate observed in the EDTA system. In order to reveal the rate dependence on the ligand, the adsorption equilibrium constants for Cu(II)-ligand complex onto the adsorbed ligand and the maximum deposition rates were determined based on the plating model previously proposed. The dependence was explained using the ligand adsorption equilibrium constant; (K1) onto the reactive surface; (K2) onto the adsorbed complexes and (K3) the complex adsorption equilibrium constant.
Genesis of Highly Active Cobalt Sulfide Catalyst for Hydrogenation and Isomerization: Effect of the Calcination Temperature of Precursor Cobalt Oxide upon the Catalytic Properties of Cobalt Sulfide
Authors: Okamoto Yasuaki , Nagata Kozo , Imanaka Toshinobu , Inamura Kazuhiro , Takyu Toshiyuki
Published: July 2006

It was found that the catalytic activities and selectivities of cobalt sulfide catalysts are significantly affected by the calcination temperature of precursor cobalt oxide for the hydrogenation of butadiene and the isomerization of 1-butene. When cobalt sulfide was prepared from cobalt oxide calcined at 1473–1573 K, the specific activities per surface area of the sulfide were enhanced by 30–40 times those of cobalt sulfide prepared from cobalt oxide calcined at a conventional temperature, 573–973 K. The reaction selectivities were also strongly modified by the calcination temperature of precursor oxide. It is suggested that two different types of active sites are formed on cobalt sulfide, depending on the calcination temperature of the precursor. On the basis of XPS, XRD, SEM, and NO adsorption techniques, it is concluded that the particle size of the precursor cobalt oxide and sulfiding conditions determine the surface sulfur content and hence the catalytic properties of the sulfide catalysts. The sulfidation mechanism of cobalt oxide and active site models are proposed.
Photodissociation of Highly-Excited Triplet State of Benzophenone Studied by a Time-Resolved Thermal Lensing Technique
Authors: Kajii Yoshizumi , Suzuki Tadashi , Takatori Yoshiki , Shibuya Kazuhiko , Obi Kinichi
Published: July 2006

Two-step photo-absorption processes of benzophenone and photodissociation of the highly-excited triplet state have been investigated in solution by the time-resolved thermal lensing technique. Two-step absorption processes at 308 nm are found to be composed of the first S1 ← S0 absorption followed by a rapid intersystem crossing to T1 and the second Tn ← T1 absorption. The quantitative analysis of time-resolved thermal lensing signals leads to an unexpected result that only 51 ± 6 % of the photon energy absorbed by the molecule in T1 has been detected as the heat released back to the system. This observation could be explained by a model that a fast photodissociation of benzophenone takes place from Tn. The chemical evidence and energy consideration support the dissociation into two phenyl radicals and a carbon monoxide molecule.
N-Hydroxy Amides. X. Synthesis of a Nonapeptide with an Ala-(HO)Gly-Ala Sequence and Its Spectral and Iron(III) Holding Properties
Authors: Akiyama Masayasu , Katoh Akira , Iijima Masakazu , Takagi Takeshi , Natori Keiko , Kojima Tomoaki
Published: July 2006

A nonapeptide with an Ala–(HO)Gly–Ala sequence has been synthesized via condensation of appropriately protected tripeptide units. 1H NMR and CD spectral data indicate that the nonapeptide has a disordered structure in DMSO and water. The peptide forms a 1 : 3 complex of iron(III) with hydroxamate groups at neutral pH when mixed with an aqueous iron(III) solution. The complex shows λmax at 410 nm with an ε of 2160 at pH 7. Alanine residues influence the hydroxamate groups to produce a chiral complex, the CD spectrum of which reveals bands at 355 nm (Δε+0.8) and 435 nm (Δε−1.8), showing a preference for the Δ-configuration around the iron.
Formation and Reaction of Carbonyl Ylides. Reactions of 1-Methoxy-2-benzopyrylium-4-olate with Isothiocyanates
Authors: Ibata Toshikazu , Nakano Hirofumi , Tamura Hatsue
Published: July 2006

The 1,3-dipolar cycloaddition of 1-methoxy-2-benzopyrylium-4-olate (2) generated by Cu(acac)2-catalyzed decomposition of methyl 2-diazoacetylbenzoate with various aryl isothiocyanates and methyl isothiocyanate gave 2 : 1-, 3 : 1-, 4 : 1-, and 5 : 1-adducts without affording 1 : 1-adduct. The first cycloaddition of 2 occurs on the C=N double bond of isothiocyanate. The cycloadditions of the following steps, such as second, third, fourth, and fifth cycloadditions, proceed on C=O group of the cycloadducts of each previous steps. The molecular structure of the 2 : 1-adduct of 2 with phenyl isothiocyanate was determined by means of X-ray crystallography. Colorless crystals of the adduct are monoclinic with the space group P21/a, and with the unit-cell dimensions of a = 12.619 (4), b = 16.432 (4), c = 11.238 (2) Å, β = 97.39 (1)°, and Z = 4. The structure was calculated by direct methods (MULTAN 80) and refined by block-diagonal least-squares methods. All hydrogen atoms were revealed by a difference-Fourier synthesis, and further least-squares refinements gave the final R value of 0.046.
Manganese(II and III)-Mediated Synthesis of Cyclic Peroxides from Alkenes, Active Methylene Compounds, and Molecular Oxygen
Authors: Qian Chang-Yi , Yamada Takashi , Nishino Hiroshi , Kurosawa Kazu
Published: July 2006

The reaction of 1,1-diphenylethene, 1,1-bis(4-chlorophenyl)ethene, 1,1-bis(4-methylphenyl)ethene, 1,1-bis(4-methoxyphenyl)ethene, and 1,1-bis(4-fluorophenyl)ethene with 2-methyl-1,3-cyclohexanedione, 2-methyl-1,3-cyclopentanedione, 2-acetylcyclohexanone, ethyl 2-acetyl-3-oxobutanoate, 3-methyl-2,4-pentanedione, 1,3-cyclohexanedione, and 2,4-pentanedione in the presence of Mn(OAc)2 and molecular oxygen yielded the corresponding cyclic peroxides in moderate-to-good yields. Similar reaction of 1,1-disubstituted alkenes with 1,3-cyclopentanedione in the presence of Mn(OAc)3 and molecular oxygen gave 2,2,9,9-tetraphenyloctahydro-3,4,7,8-tetraoxabenz[c]indene-4a,6a-diols. Acid-catalyzed decomposition of 4-acetyl-6,6-diaryl-3-methyl-1,2-dioxan-3-ols yielded 3-acetyl-5-aryl-2-methylfurans in moderate yields. Treatment of the 4-acetyl-6,6-diaryl-3-methyl-1,2-dioxan-3-ols with alkali gave 6,6-diaryl-3-methyl-1,2-dioxan-3-ols which gave 1-aryl-1,4-pentanediones upon treatment with hydrochloric acid in acetic acid. The synthetic utility and mechanisms of the reactions are discussed.
Reactions of (E)-2-Iodo-1-tosyl-1-alkenes as Useful Synthetic Intermediates
Authors: Iwata Noriyoshi , Morioka Tetsuro , Kobayashi Toshifumi , Asada Takahiro , Kinoshita Hideki , Inomata Katsuhiko
Published: July 2006

(E)-2-Iodo-1-tosyl-1-alkenes readily available by iodosulfonization of 1-alkynes were found to be useful synthons for the regio- and/or stereoselective preparation of 1-tosyl-1-alkynes, 1-tosyl-2-alkynes, (Z)-vinyl and (Z)-allyl sulfones, β-tosyl enamines, α-tosyl ketones, α-tosyl aldehyde acetal, and β-disubstituted vinyl sulfones.
Selective Preparation of 1-Halo-2,6-dimethoxybenzenes from Bis(2,6-dimethoxyphenyl)dimethyltin
Authors: Wada Masanori , Wakamori Hiroyuki , Hiraiwa Akira , Erabi Tatsuo
Published: July 2006

With a hope to explore a facile method for preparation of 1-halo-2,6-dimethoxybenzenes, bis(2,6-dimethoxyphenyl)dimethyltin was prepared from 1,3-dimethoxybenzene, butyllithium, and dimethyltin dichloride or dimethyltin sulfide. The compound reacted with N-chlorosuccinimide and with N-bromosuccinimide in methanol to afford 1-chloro-2,6-dimethoxybenzene and 1-bromo-2,6-dimethoxybenezene, respectively. The dimethyltin by-product was obtained either as dimethyltin oxide or as dimethyltin sulfide. A reaction with iodine was performed in the presence of potassium sulfide to afford 1-iodo-2,6-dimethoxybenzene and dimethyltin sulfide. Preparation and reactions of analogous organosilanes also are described.
Acid-Promoted Reactions of Schiff’s Bases with Ketene Dithioacetal, Vinyl Sulfides, and 1,2-Propadienyl Sulfides
Authors: Narasaka Koichi , Shibata Takanori , Hayashi Yujiro
Published: July 2006

Several types of addition reactions proceed between Schiff’s bases and olefinic nucleophiles containing an alkylthio substituent. Ketene dithioacetal or 2-(methylthio)allylsilane reacts with Schiff’s bases in the presence of trifluoromethanesulfonic acid to afford β-amino acid equivalents or homoallylic amines, respectively. On the other hand, ene reaction proceeds between 1-alkyl-1,2-propadienyl sulfides and Schiff’s bases by treatment with AlCl3, giving 1,3-dienes.
Two Variants of the Topological Index and the Relations between Them
Authors: Gutman Ivan , Hosoya Haruo , Urakovic Gordana , Ristic Lidija
Published: July 2006

The two topological indices σ (recently proposed by Merrifield and Simmons) and Z (put forward by one of the present authors, Bull. Chem. Soc. Jpn., 44, 2332 (1971)) are shown to be both conceptually and numerically related. For alkanes, a linear correlation exists between ln σ and ln Z. For unbranched catacondensed benzenoid hydrocarbons σ and Z are linearly correlated. In any case σ and Z exhibit a reverse dependency on molecular structures: structural transformations having an increasing effect on Z decrease σ and vice versa.
Reactions of Water and Dinitrogen Monoxide Adsorbed on Cation-Exchanged Zeolite with Excess Electrons Generated by Gamma-Radiation
Authors: Aoki Masayoshi , Nakayama Takeshi , Nakazato Chiyoko , Masuda Takahiro
Published: July 2006

Hydrogen formation from water and nitrogen formation from dinitrogen monoxide adsorbed on a zeolite during gamma-irradiation have been studied in order to clarify the role of the metal cation contained in the zeolite and the effect of the pore size; Molecular Sieve 4A, 5A, 13X, and cation-exchanged 13X were used for that purpose. The hydrogen yield from water was observed to increase with increasing amount of adsorbed water. The dependence of G(H2) on the amount of adsorbed water was affected by the exchange of metal cations and the pore size of the zeolite. For nitrogen formation from dinitrogen monoxide in cation-exchanged 13X, the saturation behavior of G(N2) could be roughly classified into two categories, namely one approaching ca. 3 and the other around 6. The results indicate that the metal cation participates in the reaction of an excess electron with an adsorbed water molecule, at least in the range of small amounts of water.
Size of Micelles of 1-Dodecylpyridinium Chloride in Aqueous NaCl Solutions
Authors: Fujio Katsuhiko , Ikeda Shoichi
Published: July 2006

Static light scattering has been measured on aqueous NaCl solutions of 1-dodecylpyridinium chloride over the NaCl concentrations from 0 to 4.00 M at 25 °C, and the micelle molecular weight has been estimated by means of the Debye equation. In aqueous solution the molecular weight is as small as 5280, corresponding to the aggregation number, 18.6. With increasing NaCl concentration up to 0.05 M the molecular weight increases sharply, reaching 12350. The small micelles would not be so compact as the common spherical micelles but would be porous except for their core. With increasing NaCl concentration beyond 0.05 M the micelle molecular weight increases only gradually, similar to growth of the common spherical micelles, and reaches 20410 in 4.00 M NaCl.
Kinetic Studies on the Terminal Pyridine Exchange Reactions of Some Oxo-Acetate Bridged Trinuclear Ruthenium Complexes. Influence of the Metal Oxidation State and Non-Leaving Terminal Ligand (CO)
Authors: Abe Masaaki , Sasaki Yoichi , Nagasawa Akira , Ito Tasuku
Published: July 2006

Substitution reactions of py-d5 for the terminal pyridines of the three triruthenium complexes, [Ru3(μ3-O)(μ-CH3COO)6(py)3]+ (1) (Ru3(III, III, III)), Ru3(μ3-O)(μ-CH3COO)6(py)3 (2) (Ru3(II, III, III)), and Ru3(μ3-O)(μ-CH3COO)6(CO)(py)2 (3) (Ru3(II, III, III)), have been studied in CD3CN by following the change in 1H NMR spectra. The rates are practically independent of [py-d5] (0.05–1.0 mol dm−3). The first-order rate constants are 3 × 10−5 s−1 at 55 °C (ΔH≠ = 123 ± 6 kJ mol−1, ΔS≠ = +41 ± 19 J K−1 mol−1), 5.9 × 10−4 s−1 at 50 °C (ΔH≠ = 122 ± 14 kJ mol−1, ΔS≠ = +69 ± 44 J K−1 mol−1), and 3 × 10−5 s−1 at 55 °C (ΔH≠ = 126 ± 9 kJ mol−1, ΔS≠ = +52 ± 27 J K−1 mol−1) for 1, 2, and 3, respectively. Rate constants appear to depend on the apparent oxidation state of the metal center. While the three Ru ions in 2 are equivalent and each ion has average oxidation number +2(2/3), Ru ions with coordinated py in 3 are in +3 oxidation state as the +2 oxidation state is localized at carbonyl-Ru ion. A dissociative mechanism is proposed for these reactions on the basis of the absence of [py-d5]-dependence, the activation parameters, and the comparison of the rate constants with those of the substitution of methanol-d4 for the terminal water ligands in [Ru3(μ3-O)(μ-CH3COO)6(H2O)3]+.
Four Different Coordination Modes of 1,1′-Bis(diphenylphosphino)ferrocene: Synthesis, X-Ray Crystal Structure, and Iron-57 Mössbauer Spectroscopy of Four Metal Carbonyl Complexes with 1,1′-Bis(diphenylphosphino)ferrocene (dppfe)
Authors: Onaka Satoru , Moriya Takeshi , Takagi Shigeru , Mizuno Atushi , Furuta Hiroyuki
Published: July 2006

Four kinds of methal carbonyl complexes with 1,1′-bis(diphenylphosphino)ferrocene (dppfe) are synthesized and their molecular structures are determined by single-crystal X-ray analyses. Crystal data for (η5-CH3C5H4)Mn(CO)2dppfe (1), (η5-CH3C5H4)Mn(CO)dppfe (2), [ClMn(CO)4]2(μ-dppfe) (3), and CH3CCo3(CO)7dppfe (4) are as follows: 1, Pbca, a = 20.551(3), b = 28.951(5), c = 11.786(1) Å, V = 7012(2) Å3, Z = 8; 2, P21/n, a = 18.682(5), b = 20.495(4), c = 9.750(2) Å, β = 91.24(2)°, V = 3732(1) Å3, Z = 4; 3, A2/a(C2/c), a = 18.978(5), b = 15.293(4), c = 16.513(5) Å, β = 112.62(2)°, V = 4423.9(2) Å3, Z = 4; 4, , a = 13.031(2), b = 15.338(2), c = 11.583(2) Å, α = 99.13(2)°, β = 98.35(2)°, γ = 99.64(2)°, V = 2218.1(7) Å3, Z = 2; Mo Kα radiation; R = 0.075, 0.084, 0.074, and 0.056 for 2639, 4219, 2575, and 6098 reflections, respectively. Dppfe functions as a monodentate ligand in 1 with the rotational angle 128.0° for two cyclopentadienyl rings, as a bidentate chelating ligand in 2 with the rotational angles 3.1°, as a bidentate bridging ligand (no metal–metal bond) in 3 with the rotational angle 180°, and as a bridging ligand (over metal-metal bond) in 4 with the rotational angle 69.6°, respectively; Mn–P = 2.242(4) Å (1), Mn–P = 2.215(2) and 2.216(3) Å (2), Mn–P = 2.364(4) Å (3), and Co–P = 2.297(2) and 2.314(2) Å (4). The two cyclopentadienyl rings of dppfe are slightly tilted (2.3–5.7° for tilt angles in 1, 2, and 4) and are parallel in 3. The coordinated P atoms are significantly displaced from the cyclopentadienyl ring planes. From the comparison of these geometrical parameters, it is concluded that the rotation of the two cyclopentadienyl rings is a predominant factor to determine various coordination modes of dppfe rather than the tilt of the two rings and/or the deviation of the P atoms from the ring plane. The 57Fe Mössbauer spectra of this series of compounds show doublets with parameters (IS = 0.50–0.52 mm s−1 relative to Fe, QS = 2.22–2.35 mm s−1). Although isomer shifts are essentially constant, the quadrupole splittings have a tendency to increase with the increase of the rotational angle of the two cyclopentadienyl rings. 1H and 31P NMR spectra are measured for all of these compounds.
Diastereoisomers of Platinum(II) Complexes with Chiral N-Substituted 1,2-Diamines. I. Structure and Isomerization of Dichloro{(R)-2-[(2-methyl-2-aminopropyl)amino]-1-butanol}platinum(II)
Authors: Saito Reiko , Goto Masafumi , Hirose Junzo , Kidani Yoshinori
Published: July 2006

Square-planar complexes with the formula [PtCl2(R-Hb-Mepn)], where R-Hb-Mepn is (R)-2-[(2-methyl-2-aminopropyl)amino]-1-butanol CH3CH2CH(CH2OH)NHCH2C(CH3)2NH2, were synthesized and separated into two diastereoisomers. On the basis of CD spectroscopic and X-ray crystallographic analyses, (+)300- and (−)300-isomers were determined to have the R-nitrogen center with λ chelate ring and the S-nitrogen center with δ chelate ring, respectively. R(N)-[PtCl2(R-Hb-Mepn)] crystallizes in the monoclinic space group P21 with a = 8.809 (1), b = 8.9960 (4), c = 8.536 (1) Å, β = 108.787 (5)°, Z = 2, R = 0.042, and RW = 0.062. S(N)-[PtCl2(R-Hb-Mepn)] crystallizes in the orthorhombic space group P212121 with a = 9.287 (1), b = 14.831 (1), c = 9.141 (1) Å, Z = 4, R = 0.029, and RW = 0.034. 1H NMR spectra indicate that R-Hb-Mepn chelate rings take fixed conformation in acidic D2O solution. At high temeprature (90–95 °C), the conversion of the R(N)-isomer to the S(N)-isomer occurred easily. The R(N)-[PtCl2(R-Hb-Mepn)] and S(N)-[PtCl2(R-Hb-Mepn)], respectively, show the opposite Cotton effect to that of the reported complexes R(N)-[PtCl2(S-Me-pn)] and S(N)-[PtCl2(S-Me-pn)] (S-Me-pn = (S)-1-methylamino-2-aminopropane). The kinetic data of a reversible inversion reaction at the nitrogen were consistent with the usual base catalyzed mechanism.