bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and Properties of Tetrathia[n](1,1′)ferrocenophanes with Pd(BF4)2. The Metal–Metal Interaction Controlled by the Size of the Thiamacrocycles
Authors: Sato Masaru , Akabori Sadatoshi
Published: July 2006

1,4,7,10-Tetrathia[10]-, 1,4,8,11-tetrathia[11]-, 1,5,8,12-tetrathia[12]-, and 1,5,9,13-tetrathia[13](1,1′)ferrocenophanes reacted with (CH3CN)4Pd(BF4)2 to give the corresponding 1/1 complexes in good yield. The 1H NMR spectra of the Pd(II) complexes were not rigid at room temperature, except for the complex of 1,4,7,10-tetrathia[10](1,1′)ferrocenophane. The 1H and 13C NMR spectra at low temperature showed that the Pd(II) complex of 1,5,9,13-tetrathia[13]ferrocenophane was a single compound, while the other three complexes were a mixture of two isomers. In the electronic spectra of the above series, the low-energy band shifted to the long-wavelength region and increased its absorbance according to the decrease in the size of the thiamacrocycle.
Substituted Bisphenols as Antioxidants for Autoxidation of Tetralin
Authors: Yamada Fukiko , Nishiyama Tomihiro , Yamamoto Masahiro , Tanaka Kazunori
Published: July 2006

The antioxidative activities of nineteen compounds of seven series of alkylidene- and benzylidenebisphenols were evaluated by means of an oxygen-absorption method at 60 °C for tetralin. The electrochemical oxidation potentials determined using linear-sweep voltammetry and the 13C NMR chemical shifts (δ) of these compounds were obtained. These data were associated with the antioxidative activities. In particular, the activities exhibited by the induction period (min) were found to closely correlate with the 13C chemical shifts of the ipso-carbon of the OH substituent (corr. coeff.=0.991). Very good activities have been observed with a series of 2,2′-alkylidene- and benzylidenebis(4,6-dimethylphenol) derivatives.
Extraction Spectrophotometric Determination of Bismuth(III) with Iodide and Amidines
Authors: Ghosh Alpana , Patel Khageshwar Singh , Mishra Rajendra Kumar
Published: July 2006

A new simple and rapid spectrophotometric method for the extraction and determination of bismuth(III) is described. The reaction of N,N′-diphenylbenzamidines and its 10 derivatives (HA) with bismuth(III) in presence of iodide have been investigated photometrically in chloroform. The value of molar absorptivity of the complexes with these compounds lies in the range (0.84–1.35)×104 l mol−1 cm−1. Of these, the most sensitive compound N-(2-methylphenyl)-N′-phenylbenzamidine hydrochloride (MPPBA) was selected for detailed studies. The detection limit of the method is 0.2 μg Bi cm−3. The elements which are commonly associated with the metal e.g. Cu, Ni, Co, Mn, Cr, Zn, Hg, Ti, Zr, Mo, W, V, Al, Sb, etc. do not interfere. The method has been applied for the determination of the metal to soil and ore.
Studies of Collectors. X. Complexing Ability of Amino Hydroxamic Acid Ligands with Dioxouranium(VI) in Aqueous Solution
Authors: Koide Yoshifumi , Uchino Masazumi , Shosenji Hideto , Yamada Kimiho
Published: July 2006

Complexing ability of ligands bearing hydroxyaminocarbonyl group and amino group with UO22+ in an aqueous solution were examined by the potentiometric method using MINIQUAD program. Stability constants of 2-aminoacetohydroxamic acid complex with UO22+ are logβ1=10.45, logβ2=18.95. They are far larger than those of acetohydroxamic acid complexes. The β1 and β2 are almost the same as β1 and β2 of the acetamide oxime (acetoamidoxime) complexes.
The Reaction of N″-Cyanoguanidine with Formaldehyde. IV. The Formation Pathway of 4-Cyanoimino-3-(methoxymethyl)perhydro-1,3,5-oxadiazine
Authors: Shiba Ryuichi , Takahashi Miyuki , Ebisuno Toichi , Takimoto Michiaki
Published: July 2006

An investigation of reactions involving N″-cyanoguanidine (CG) and its methyl derivatives with formaldehyde as well as the consideration of the molecular structures of CG and 4-cyanoimino-3-(methoxymethyl)perhydro-1,3,5-oxadiazine elucidated the formation pathway of the latter compound from CG: CG → N-hydroxymethyl N″-cyanoguanidine → N,N′-bis(hydroxymethyl)-N″-cyanoguanidine → 4-(cyanoimino)perhydro-1,3,5-oxadiazine → 4-cyanoimino-3-(hydroxymethyl)perhydro-1,3,5-oxadiazine → 4-cyanoimino-3-(methoxymethyl)perhydro-1,3,5-oxadiazine.
Oxidation Using Quaternary Ammonium Polyhalides. V. Selective Oxidation of Benzyl Alcohols by the Use of Benzyltrimethylammonium Tribromide
Authors: Okamoto Tsuyoshi , Uesugi Takeshi , Kakinami Takaaki , Utsunomiya Tomohisa , Kajigaeshi Shoji
Published: July 2006

The reaction of several substituted benzyl alcohols with 1 equiv of benzyltrimethylammonium tribromide (BTMA Br3) in carbon tetrachloride under basic or neutral conditions gave the corresponding benzaldehydes, and with 2 equiv of BTMA Br3 in aqueous alkaline solution and subsequent acid hydrolysis gave the corresponding benzoic acids, respectively, in satisfactory yields.
Myeloperoxidase Catalyzed Bromination of Nucleic Acid Bases and Related Compounds
Authors: Itahara Toshio , Ide Naoko
Published: July 2006

Oxidation of cytosine, uracil, adenine, cytidine, and 2′-deoxycytidine by myeloperoxidase in the presence of hydrogen peroxide and potassium bromide in sodium acetate buffer solution at pH 5.0 resulted in bromination of the substrates. A comparison of bromination of 1,3-dimethyluracil catalyzed by peroxidases such as myeloperoxidase, lactoperoxidase, chloroperoxidase, and horseradish peroxidase was also studied.
NMR Determination of Association Constants for Aqueous Calixarene Complexes and Guest Template Effects on the Conformational Freedom
Authors: Shinkai Seiji , Araki Koji , Matsuda Tsutomu , Manabe Osamu
Published: July 2006

The association constants (K) for aqueous complexes with water-soluble p-sulfonatocalix[n]arene (1n: n=4, 6, and 8) were determined by the NMR method. It was found that 14 and 16 form 1 : 1 complexes with guest molecules (trimethylanilinium chloride and 1-adamantyltrimethylammonium chloride), whereas 18 forms 1 : 2 18/guest complexes. The finding supports the view that calixarenes 1n’s are capable of molecular recognition on the basis of the ring size. Examination of the thermodynamic parameters for the association process established that the complexation with 14 is mainly due to the electrostatic force, whereas that with 16 and 18 is mainly due to the hydrophobic force. The coalescence temperatures (Tc’s) for calixarene ring inversion were subject to the template effect by these molecules. The activation parameters for the rate of ring inversion were estimated by a computer-assisted spectrum simulation: it was found that the Tc increase, observed in the presence of these guest molecules acting as templates, is caused by the increase in ΔH\eweq. These findings provide new insights into the association characteristics of water-soluble calixarenes.
Synthesis of 2-Amino-2-deoxy-α-d-altrofuranoside Derivatives from 2,3-O-Isopropylidene-d-glyceraldehyde via Bicyclic β-Lactam Intermediates
Authors: Shiozaki Masao , Ishida Noboru , Sato Sadao
Published: July 2006

A bicyclic β-lactam (4), obtained from 2,3-O-isopropylidene-d-glyceraldehyde in 3 steps, was converted to methyl 2-benzamido-2-deoxy-5,6-O-isopropylidene-3-O-(3-chlorobenzoyl)-α-d-altrofuranoside (24) through an additional 8 steps by utilizing the β-lactam nitrogen via the oxidative decarboxylation of diacyl peroxide (23). Additionally, it was shown that the bicyclic β-lactam intermediate is a suitable precursor for 2-amino-3-(branched-chain)-2-deoxy-d-furanoside derivatives.
The Structure of Rotungenoside, a New Bitter Triterpene Glucoside from Ilex Rotunda
Authors: Nakatani Munehiro , Hatanaka Shuichi , Komura Hajime , Kubota Takashi , Hase Tsunao
Published: July 2006

A new bitter triterpene ester glucoside have been isolated along with known bitter triterpene glucoside peduncloside and some minor triterpenes ulsolic acid, rotundic acid, and rotungenic acid from the unripe fruits of Ilex rotunda. The structure was characterized as β-d-glucopyranosyl 3β,19α,24-trihydroxyurs-12-en-28-oate by spectral data and chemical means.
Novel Structures of 1:1 Complexes of 1,4,7,10,13-Pentaoxa-, 1,13-Dioxa-4,7,10-trithia[13]- and 1,4,7,10,13,16-Hexaoxa[16](1,1′)ruthenocenophanes with HgCl2: Metal–Metal (Ru–Hg) Bond Formation
Authors: Sato Sadao , Sato Masaru , Akabori Sadatoshi
Published: July 2006

The structures of 1:1 complexes (3b, 4b, and 5b) of 1.4,7,10,13-pentaoxa-, 1,13-dioxa-4,7,10-trithia[13]- and 1,4,7,10,13,16-hexaoxa[16](1,1′)ruthenocenophanes (3a, 4a, and 5a) with HgCl2, and 3a have been determined by the single-crystal X-ray diffraction method. The complexing forms of the three complexes are quite similar to each other. Crystal data: 3b, triclinic, space group P\bar1, a=12.043(3), b=10.759(2), c=8.529(2) Å, α=98.76(2), β=101.22(2), γ=77.03(2)°, U=1049.5 Å3, Z=2, Dc=2.19 g cm−3, μ(Mo Kα)=84 cm−1. 4b, triclinic, space group P\bar1 a=17.100(3), b=8.986(1), c=8.618(2) Å, α=105.17(1), β=62.24(1), γ=100.54(1)°, U=1128.1 Å3, Z=2, Dc=2.18 g cm−3, μ(Mo Kα)=81 cm−1. 5b, monoclinic, a space group P21⁄a, a=26.881(7), b=10.344(3), c=8.414(2), β=96.97(2)°, U=2322.2 Å3, Z=4, Dc=2.11 g cm−3, μ(Mo Kα)=76 cm−1. 3a, triclinic, space group P\bar1, a=11.107(1), b=8.816(1), c=9.788(1) Å, α=70.48(1), β=99.76(1), γ=101.31(1)°, U=877.6(2) Å3, Z=2, Dc=1.59 g cm−3, μ(Mo Kα)=9 cm−1. Only the Ru atom of the ruthenocene nucleus of these complexes was coordinated to HgCl2 with a slightly distorted trigonal-planar configuration. The distances between the Ru and the Hg atoms are 2.683(3), 2.704(1), and 2.696(2) Å, respectively.
The Removal of Nitrogen Monoxide by the Dry Iron(II) Complex Immobilized on Chelate Resin. The Preparation and Characterization of the Complex
Authors: Toshima Naoki , Asanuma Hiroyuki , Hirai Hidefumi
Published: July 2006

A new dry-type adsorbent for nitrogen monoxide was successfully prepared from an iron(II) salt and a chelate resin containing iminodiacetic acid moieties. The capability of adsorbing nitrogen monoxide depended greatly on the method of preparation. The very active adsorbent was prepared by mixing 31.4 mmol of iron(II) sulfate and a commercial chelate resin containing 21.0 mmol of iminodiacetic acid moieties; the mixture was dried after the solid parts had been washed with methanol. The resulting solid adsorbent could adsorb more than 99% of the nitrogen monoxide from 6 dm3 of nitrogen gas containing 1000 ppm of nitrogen monoxide within 25 min. This high capability for adsorbing nitrogen monoxide was derived from the increase in the surface area (43.1 m2 g−1) of the resin-immobilized iron(II) complex upon washing with methanol. The mechanism for the increase in the surface area is also discussed.
Unusually High Oxidation Half-Wave Potentials of Di- and Trichalcogena[3]ferrocenophanes. The Effect of Chalcogen Atoms in the Bridge
Authors: Ushijima Hirobumi , Akiyama Takeo , Kajitani Masatsugu , Shimizu Kunio , Aoyama Masahide , Masuda Shigeru , Harada Yoshiya , Sugimori Akira
Published: July 2006

1,2,3-Trithia[3]ferrocenophane (1a) and related compounds show a well-defined reversible one-electron oxidation wave (Fe(III)/Fe(II)) in cyclic voltammetry. The [3]ferrocenophanes with S and/or Se atoms in the bridge show unusually high oxidation half-wave potentials which have not been observed either in [3]ferrocenophane or in 1,1′-bis(methylchalcogeno)ferrocenes. The effect of chalcogen atoms at the 1,3-positions in the bridge on the positive shift of half-wave potentials is larger than that at the 2-position. Two kinds of electron-attracting effects of chalcogen atoms at the 1,3-positions in the bridge are proposed: an inductive electron-attracting effect (“through-bond” effect) and the interaction between the d-orbitals of Fe and chalcogen (“through-space” interaction). The role of the sulfur atom at the 2-position in the bridge is to stabilize the electron attracted by the sulfur atoms at the 1,3-positions by conjugation of three sulfur atoms.
Thermal Behavior and Characterization of Some 2-Oxazolidinone Derivatives
Authors: Shimasaki Choichiro , Hayase Shuichi , Murai Atsuko , Takai Junko , Tsukurimichi Eiichi , Yoshimura Toshiaki
Published: July 2006

Four kinds of 2-oxazolidinone derivatives, (1) [5-phenoxymethyl-3-phenylcarbamoyl-2-oxazolidinone (1a), 2,4-bis(2-oxo-3-oxazolidin-3-ylcarbonylamino)toluene (1b), N,N′-bis(2-oxo-3-oxazolidin-3-ylcarbonyl)-1,6-hexanediamine (1c), and 1,4-bis(3-phenylcarbamoyl-2-oxo-5-oxazolidin-5-ylmethoxy)benzene (1d)], were prepared with the addition of 2-oxazolidinone, 5-phenoxymethyl-2-oxazolidinone (2), and 1,4-bis(2-oxo-5-oxazolidin-5-ylmethoxy)benzene (3) to mono- or diisocyanates by using N,N-dimethylformamide or benzene as solvents and 1,4-diazabicyclo[2.2.2]octane as a catalyst. Compound 1 was found to be thermally stable by thermal analysis. DSC curves of these compounds revealed an endothermic peak due to melting, except for 1d which was obtained from 3. The main fragmentation mechanism by electron impact for 1 was found to consist of two processes: simple cleavage and a rearrangement reaction. Further, each process was followed by cleavage modes. The proportion of fragment ions containing the benzene ring in the main fragmentation was greater than 80%. From the DTA-TG/DTG curves, the difference between EI-cleavage and thermal decomposition for 1a was elucidated.
End Groups of Poly(methyl methacrylate) as a Function of Molecular Weight Determined by Pyrolysis-Gas Chromatography
Authors: Ohtani Hajime , Tanaka Minoru , Tsuge Shin
Published: July 2006

End groups of poly(methyl methacrylate) (PMMA) radically polymerized with benzoyl peroxide (initiator) in toluene solution were investigated by pyrolysis gas chromatography as a function of molecular weight. The number-average molecular weights (\barMn) of fractionated PMMA samples were estimated from the relative peak intensities of characteristic pyrolysis products and were compared with those determined by size exclusion chromatography. The observed result suggested that the chain transfer reactions to the monomer might yield relatively smaller PMMA molecules. Furthermore, the relative peak intensities among aromatic products which reflect three kinds of aromatic chain ends were correlated to the (\barMn) of the fractionated PMMAs. The result suggested that the chain transfer reaction to the solvent also tended to yield relatively smaller PMMA molecules whereas the polymerization initiated by the phenyl radical from the initiator yielded relatively larger PMMA molecules under given polymerization conditions.
35C1 NQR of 1:2 Complexes of SnCl4 with Several Nitriles
Authors: Mishima Mitsuo , Okuda Tsutomu
Published: July 2006

35C NQR spectra have been obtained for the complexes of SnCl4·2RCN (R=CH3, CD3, t-C4H9, or C6H5). The NQR spectra reveal the existence of three crystal modifications in SnCl4·2CH3CN, a stable phase (Form-1) and two metastable ones (Form-2 and Form-3). Form-3 was obtained as a mixture with Form-2. These modifications are suggested to be cis isomers. The complex, SnCl4·2C6H5CN, has likewise yielded three modifications, and the evidence for cis–trans isomerization in this complex has been found from NQR spectra. A Zeeman analysis on single crystals reveals that SnCl4·2t-C4H9CN has a cis form and that its molecular geometry is similar to Form-1 of SnCl4·2CH3CN. In these complexes, the equatorial Cl atoms yield asymmetry parameters of 0.05 to 0.08 and the axial ones negligibly small values. The temperature dependence plot for the NQR frequencies in SnCl4·2CH3CN yields unusual curves. This is attributed to some interaction between the Cl atom and the methyl groups.
NAD(P)+–NAD(P)H Models. 71. A Convenient Route to the Synthesis of Juvabione
Authors: Fujii Masayuki , Aida Tetsuo , Yoshihara Masakuni , Ohno Atsuyoshi
Published: July 2006

Synthesis of juvabione in short steps in a high overall yield has been achieved via the chemoselective reduction with Hantzsch ester (HEH) in the presence of silica gel as a key step.
Convenient and Efficient Tosylation of Oligoethylene Glycols and the Related Alcohols in Tetrahydrofuran–Water in the Presence of Sodium Hydroxide
Authors: Ouchi Mikio , Inoue Yoshihisa , Liu Yu , Nagamune Satoshi , Nakamura Satoko , Wada Kazuhito , Hakushi Tadao
Published: July 2006

Oligoethylene glycols and some related alcohols were efficiently tosylated with p-toluenesulfonyl chloride in a tetrahydrofuran–water (1:1) mixture in the presence of excess sodium hydroxide. This method is advantageous over the conventional tosylation in pyridine both regarding the work-up procedure, the yield, and the purity of the product, and may be potentially useful for the tosylation of certain acid-labile alcohols.
A New Synthesis of β-Keto Sulfoxides from Chloromethyl Aryl Sulfoxide and Aldehydes
Authors: Satoh Tsuyoshi , Fujii Takako , Yamakawa Koji
Published: July 2006

Addition of the carbanion of chloromethyl aryl sulfoxide to aldehyde gave the adduct, which was treated with three-equivalents of lithium diisopropylamide (LDA) to afford β-keto sulfoxide in high overall yield.
Electronic Structure of Chiral Halomethanes
Authors: Novak Igor
Published: July 2006

The electronic structures of 5 possible chiral halomethanes have been studied using relativistic and nonrelativistic semiempirical MO calculations. Some thermodynamic properties of title molecules and their vibrational modes are also described in the light of calculations performed.
Thermally Irreversible Photochromic Systems. Reversible Photocyclization of 1,2-Bis(benzo[b]thiophen-3-yl)ethene Derivatives
Authors: Uchida Kingo , Nakayama Yasuhide , Irie Masahiro
Published: July 2006

1,2-Bis(benzo[b]thiophen-3-yl)ethene derivatives, which possess thermally irreversible and fatigue resistant photochromic properties, were synthesized, cis-1,2-Dicyano-1,2-bis(2-methylbenzo[b]thiophen-3-yl)ethene 1a and 2,3-bis(2-methylbenzo[b]thiophen-3-yl)maleic anhydride 2a underwent reversible photocyclization to produce red-colored closed-ring forms with λmax at 507 nm and 544 nm, respectively. The closed-ring forms were stable for more than 3 weeks at 80 °C. The coloration/decoloration (ring closure/opening)cycles were able to be repeated more than 104 times with keeping the adequate photochromic performance.
Kinetics of the Ligand Substitution Reactions of a Labilized Ruthenium(III) Complex, [Ru{N′-(2-hydroxyethyl)ethylenediamine-N,N,N′-triacetate}(H2O)]
Authors: Ogino Hiroshi , Katsuyama Tetsuo , Ito Setsuo
Published: July 2006

The kinetics of the substitution reactions of [N′-(2-hydroxyethyl)ethylenediamine-N,N,N′-triacetato]-aquaruthenium(III), [Ru(hedtra)(H2O)], with X (Br−, CH3CN, SCN−, and pyridine) to give [RuX(hedtra)] were carried out at 25 °C and I=0.5 mol dm−3. The substitution reactions were found to be unusually rapid. The rate constants of the forward reaction (kf) and of the backward reaction (kb) were kf=0.13±0.01 mol−1 dm3 s−1 and kb=(1.9±0.2)×10−2 s−1 for the reaction with Br−, kf=0.48±0.02 mol−1 dm3 s−1 and kb=(3.0±0.2)×10−2 s−1 for the reaction with CH3CN, and kf=7.5±0.2 mol−1 dm3 s−1 and kb=(1.3±0.8)×10−2 s−1 for the reaction with SCN−, respectively. The kinetics of the reaction of [Ru(hedtra)(H2O)] with py was studied as a function of pH. The observed rate constants of the reaction were separated into two rate constants; the rate constant of the forward reaction of [Ru(hedtra)(H2O)] with py (18±2 mol−1 dm3 s−1) and that of [Ru(OH)(hedtra)]− with py (3.0±1.0 mol−1 dm3 s−1). The mechanisms of the reactions are discussed.
Synthesis and Ion Exchange Properties of Sodium Stannosilicate: A Silver Selective Inorganic Ion Exchanger
Authors: Rawat Jagdish Prasad , Ansari Abdul Aziz
Published: July 2006

An inorganic ion exchanger sodium stannosilicate has been synthesized. Its composition, chemical and thermal stabilities and ion exchange properties have been studied. This material is obtained as hard granules and is very stable at high temperatures. Its ion exchange capacity for Ag+ is 2.25 mequiv g−1. The material shows high selectivity towards Ag+ which has been separated quantitatively from Pb2+, Hg2+, and Cu2+. Recovery of Ag+ from dilute solutions has also been studied.
Normal Vibrations of 4-Methyl- and 4-Methyl-d3-pyridines
Authors: Yoshikai Kazumasa , Hieida Toshikazu , Nibu Yoshinori , Shimada Hiroko , Shimada Ryoichi
Published: July 2006

Assignment of the normal vibrations of 4-methylpyridine was made through the vibrational analyses of the Raman and infrared spectra and also through the normal coordinate calculation. The assignment was confirmed by the study made on 4-methyl-d3-pyridine.
Trimethylsilyl Derivatives of Alkyltrimethylammonium–Kanemite Complexes and Their Conversion to Microporous SiO2 Materials
Authors: Yanagisawa Tsuneo , Shimizu Toshio , Kuroda Kazuyuki , Kato Chuzo
Published: July 2006

Alkyltrimethylammonium–kanemite complexes, having three dimensional SiO2 networks, were allowed to react with a trimethylsilylating reagent to form the trimethylsilylated derivatives. The three dimensional SiO2 networks were retained after trimethylsilylation. The calcined products obtained from the trimethylsilylated products had about 840–880 m2 g−1 in specific surface areas and micro pores with 22–33 Å in average pore diameter. These values were slightly smaller than those of the calcined products obtained from alkyltrimethylammonium–kanemite complexes, which indicated the effect of the trimethylsilyl groups.
Hydrothermal Synthesis of Calcium Silicate of ZSM-5 Structure in Alkali-Metal-Cation-Free Conditions
Authors: Okabe Kiyomi , Matsuzaki Kenji , Hagiwara Hiroyuki
Published: July 2006

Crystalline calcium silicate of ZSM-5 structure was hydrothermally synthesized by using an excessive amount of tetrapropylammonium bromide (TPABr) as an organic base and without using any alkali metal ions in the low pH range. The acidity caused by Ca was verified by IR, NH3-TPD, and methanol conversion.
The Migration of Barium into Zeolite Channels from the Outer Surfaces of Zeolite Crystals
Authors: Sano Tsuneji , Okado Hideo , Shoji Hiroshi , Ikai Shigeru , Takaya Haruo
Published: July 2006

For the ZSM-5 zeolite mechanically mixed with barium carbonate, the migration of barium into the zeolite channels from the outer surfaces of zeolite crystals occurs at 600 °C in both the absence of and the presence of steam, resulting in a modification of the strong acid sites.
Resonance Raman Active Vibrations of Blue Copper Proteins. Normal Coordinate Analysis on 169-Atom Model
Authors: Urushiyama Akio , Tobari Jiro
Published: July 2006

Normal coordinate analyses were performed for three crystallographically defined blue copper proteins: Alcaligenes denitrificans azurin, Pseudomonas aeruginosa azurin, and poplar leaf plastocyanin. A maximum of 485 internal coordinates were specified from a model constructed by the analyzed coordinates of the 169 atoms around the type-1 blue copper site. Mass-group approximation was employed for CH, CH2, CH3, NH, and NH2 groups throughout. With the use of reasonable force constant values, the standard GF calculation method always gives rise to extensive couplings of Cu–S(cysteine) stretching coordinate to the bending coordinates widely distributed in the molecule. Several normal vibrational modes having appreciable PED values of the Cu–S(cysteine) stretching coordinate are correlated with the characteristic RR lines of the blue copper proteins in the 370–450 cm−1 region. Our data indicate that the protein-sensitive variation of the RR pattern might be ascribed to a difference in the peptide structure around the blue copper site, rather than to the structure of the Cu coordination sphere, itself.
Lewis Acid Catalyzed Reaction of o-[1-(Alkylthio)alkyl]phenols: The Generation and Reaction of o-Quinonemethides and Applications to Cannabinoid Synthesis
Authors: Inoue Tsutomu , Inoue Seiichi , Sato Kikumasa
Published: July 2006

o-Quinonemethides were prepared by treating o-[1-(alkylthio)alkyl]phenols with a Lewis acid. The Diels–Alder reaction of the resulting o-quinonemethides was also catalyzed by the Lewis acid. Hexahydrocanna-binol was synthesized according to this method.
Synthesis and Radical Induced Ring Opening Reaction of 1-Trialkylsilyl-2-vinylcyclopropanes
Authors: Miura Katsukiyo , Oshima Koichiro , Utimoto Kiitiro
Published: July 2006

A variety of trialkylsilylvinylcyclopropanes were prepared by two different routes: (a) Cyclopropanation of 1-alkenylsilanes and (b) the reactions of 1-bromocyclopropyllithium with trimethylsilyl chloride. Radical induced ring opening reaction of these cyclopropanes were examined. 1-Dimethylphenylsilyl-2-vinylcyclopropane or 3-methyl-1-trialkylsilyl-2-vinylcyclopropane provided the corresponding homoallylic silane exclusively upon treatment with PhSH, Ph3SnH, n-Bu3SnH, or n-C6F13I. On the other hand, 2-phenyl-1-trimethylsilyl-3-vinylcyclopropane or 2-acetyl-1-trimethylsilyl-3-vinylcyclopropane gave allylic silane selectively.
A Study on Peierls Instability in Quasi-One-Dimensional-System with Interchain-Interactions. Semi-Empirical Self-Consistent-Field Molecular Orbital Approach
Authors: Watanabe Eijiro , Imamura Akira
Published: July 2006

It is widely known that interchain-interactions diminish the Peierls instability in a one-dimensional electronic system. We studied the electronic structure of the (–H–) chains as a model system for the quasi-one-dimensional system. We compare the result of a Hartree–Fock type calculations for a non-interaction chain, a two-chain model with interchain-interactions, two-chain model with interchain-interactions, and a two-dimensional model in which infinite number of chains on the same plane interact with each other. The energy band and the total energy are obtained by the LCAO crystal orbital method using the CNDO/2 approximation. According to the calculated total energy in models with interchain-interactions, for both two-chain and two-dimensional models, the Peierls instability decreases, and disappears for a strong interchain-interaction.
Nonlinear Phenomena in Bromate–Bromide–Cerium(III) System in a Continuous-Flow Stirred Tank Reactor: Reaction Behavior near the Crossing Point in a Cross-Shaped Phase Diagram
Authors: Sasaki Yoshihiro
Published: July 2006

The behavior of a bromate–bromide–cerium(III) system in a continuous-flow stirred tank reactor was simulated near the crossing point in the cross-shaped phase diagram obtained by using linearized stability analysis. The transitions between monostable states and an oscillatory state occur through supercritical and subcritical Hopf bifurcations. The steady states (SSI and SSII) in the neighborhood of the bifurcation points of the subcritical Hopf bifurcations are excitable against perturbations of the concentration of bromide. Some properties of the excitation were also examined. Complicated bifurcations associated with excitability are found in the bistable region near the crossing point. In order to understand bistability and oscillations in this system, the dynamical behavior of a five-variable model was examined by means of a two-variable approximation.
Synthetic Studies on Terpenoid Compounds. XXXIII. A Total Synthesis of (±)-15,16-Epoxy-cis-cleroda-3,13(16),14-triene
Authors: Tokoroyama Takashi , Kanazawa Reizo , Yamamoto Satoru , Kamikawa Tadao , Suenaga Hitoshi , Miyabe Makiko
Published: July 2006

A total synthesis of title cis-clerodane diterpene 9 has been achieved starting from a bicyclic intermediate 4, which was developed previously by us. Firstly the compound 4 was converted by five steps to octalone derivative 6, of which angular methylation, with the protection of 3-methylene group, afforded cis-decalone 7. Appendage of 3-furyl group and deoxygenation at C-20 carbon atom transformed the compound 7 to furanoid ketone 8. Methylenation of 8 followed by the double bond isomerization led to the completion of the synthesis.
New Near Infrared Absorbing Metal Complex Dyes: Synthesis and Metallochromic Properties of Two Isomeric Ligands, 2-(Dimethylamino)naphtho {[1,2-g] and [2, 1-g]} quinoline-7,12-diones
Authors: Yoshida Katsuhira , Koujiri Tetsunao , Sakamoto Eriko , Kubo Yuji
Published: July 2006

The Diels–Alder reaction of 5,8-quinolinedione with p-(dimethylamino)styrenes gave new two kinds of isomeric dyes, 2-(dimethylamino)naphtho[1,2-g]quinoline-7,12-diones and 2-(dimethylamino)naphtho[2,1-g]quinoline-7,12-diones, which showed quite different metallochromic behaviors. Upon addition of metal salts, one of the two isomers showed drastic spectral changes to have an intense absorption band in near infrared region. The color–structure relations were investigated.
Mesomorphic Properties of Bis(4-alkoxycarbonylphenyl)terephthalates
Authors: Matsunaga Yoshio , Miyajima Nobuhiko
Published: July 2006

The mesomorphic behavior of fifteen bis(4-alkoxycarbonylphenyl)terephthalates has been examined in order to study the effects of branching of the ester alkyl groups. The 2-methylation of purely smectogenic butyl, pentyl, and hexyl esters gives rise to the appearance of nematic properties.
Preparation and Molecular Structure of (Methoxo)(octaethylporphinato)iron (III)
Authors: Hatano Keiichiro , Uno Tadayuki
Published: July 2006

The X-ray structure of Fe(OEP)(OMe) is reported: Fe(C36H44N4)(CH3O), F.W.=619.7, monoclinic, P21/c, a=13.412(5) Å, c=18.912(8) Å, β=106.28(3)° and V=3348(4) Å3, Z=4. A methoxide-coordinated iron(III) porphyrinate with π-π dimeric porphyrin interaction in the solid state was revealed. The facile formation of the methoxide is briefly discussed.
Tetramerized Structure of (DMET)2ReO4 and Its Apparent Metallic Behavior in Resistivity
Authors: Saito Kazuya , Ishikawa Yoshimitsu , Ishibashi Masayoshi , Kikuchi Koichi , Kobayashi Keiji , Ikemoto Isao
Published: July 2006

The crystal structure of (DMET)2ReO4 (DMET: 5,6-dihydro-2-(4,5-dimethyl-1,3-diselenol-2-ylidene)dithiolo[4,5-b][1,4]dithiin) was determined, and its resisitivity and thermoelectric power were measured. Crystal data; (C10H10S4Se2)2·ReO4, Mr=1082.88, triclinic, P\bar1, a=6.715(1) Å, b=14.486(2) Å, c=15.867(2) Å, α=101.95(4)°, β=90.05(1)°, γ=78.43(1)°, V=1478.2(3) Å3, Z=2, Dx=2.43 Mg m−3, μ(Mo Kα)=9.62 mm−1, F(000)=1022, T=297 K, R=0.074 for 4391 reflections. The crystal has columnar structure. In the column, a large degree of tetramerization is observed. The resistivity under the normal pressure has metallic temperature dependence above ca. 295 K. The thermoelectric power is essentially constant above 200 K and no anomaly was detected around 295 K. The apparent metallic behavior was attributed to the small activation energy (band-gap) and the temperature dependence of the carrier mobility.
The Application of ESR Spin-Trapping Technique to the Evaluation of SOD-like Activity of Biological Substances
Authors: Mitsuta Keiichi , Mizuta Yukio , Kohno Masahiro , Hiramatsu Midori , Mori Akitane
Published: July 2006

The SOD-like activity of several biological substances was evaluated by an ESR spin-trapping technique. Superoxide radicals (O2\ewdot) were supplied enzymatically from a hypoxanthine–xanthine oxidase reaction to the evaluating system. By using a spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO), the generated O2\ewdot was trapped stoichiometrically (1:1) as the spin adduct of O2\ewdot (DMPO–O2−). When biological substances were added to the system, a decrease in the ESR signal intensities of the adducts was observed. This phenomenon could be explained as being an inhibition of adduct formation, and related to the reactivity of added biological substances with O2\ewdot, called an SOD-like activity. By the method of kinetic competition with a 50% inhibitory dose (ID50), the second-order rate constant for the reaction between O2\ewdot and biological substance was determined. These rate constants can be used as a measure of the reactivity.
Lithium Alkylamide Catalyzed Addition Reaction of Alkylamine to Vinyl Monomers. II. Preparation and Q,e-Values of New Styrene Derivative: (S)-N-α-Methylbenzyl-3-vinylphenethylamine
Authors: Hamana Hiroshi , Horiguchi Koichi , Hagiwara Tokio , Narita Tadashi
Published: July 2006

The lithium alkylamide catalyzed addition reaction of α-methylbenzylamine with 1,3-divinylbenzene (m-DVB)was found to produce N-α-methylbenzyl-3-vinylphenethylamine (1:1 adduct) (m-MBVPA), which is a new styrene derivative, and 1,3-bis(N-α-phenethyl-2-aminoethyl)benzene (1:2 adduct). The specific rotation of (S)-N-α-methylbenzyl-3-vinylphenethylamine derived from the optically active (S)-α-methylbenzylamine with m-DVB was found to be [α]D6=−62.2°(c 1.46, CH3OH). The higher reactivity of 1,4-divinylbenzene (p-DVB) compared to m-DVB in this addition reaction system is ascribable to a larger conjugation of p-DVB. The vinyl group of m-MBVPA has been found to show a higher reactivity compared to that in the adduct of MBA with p-DVB. The monomer reactivity ratios and Q,e-values obtained from the radical copolymerization of m-MBVPA (M1) and styrene (M2) were r1=0.48, r2=0.70; Q1=0.62, and e1=0.24.
Oxidation of Alcohols with Electrolytic Manganese Dioxide. Its Application for the Synthesis of Insect Pheromones
Authors: Tsuboi Sadao , Ishii Naomi , Sakai Takashi , Tari Isao , Utaka Masanori
Published: July 2006

Oxidation of alcohols with electrolytic manganese dioxide under mild conditions afforded aldehydes and ketones in good yields. The method was applied for the syntheses of cystophorene [(3E, 5Z)-1,3,5-undecatriene] (15) and a sex pheromone of forest tent cater pillar [(5Z, 7E)-5,7-dodecadien-1-ol (18)].
Reaction of β-Nitroketeneaminal with Olefins Bearing Electron-Withdrawing Group and Aldehydes
Authors: Tokumitsu Takao
Published: July 2006

The reaction of 2-(nitromethylene)imidazolidine (1) with olefins bearing an electron-withdrawing group gave Michael-type addition products and/or 5-nitro-1,7-diazabicyclo[4.3.0]nonane derivatives derived from the Michael-type adduct. The reaction of 1 with α,β-unsaturated aldehydes in the presence of an acid, on the other hand, gave similar diazabicyclic derivatives and 2-[(2-imidazolidinylidene)nitromethylene]-5-nitro-1,7-diazabicyclo[4.3.0]non-5-ene derivatives. The reaction of 1 with saturated and aromatic aldehydes in the presence of hydrochloric acid gave 1,3-bis(2-imidazolidinylidene)-1,3-dinitropropane derivatives. The enhanced enaminic character of 1 is ascribable to the two electron-donating amino groups fixed in a five-membered ring.
Oxidation of Secondary Alcohols over Hydrous Zirconium(IV) Oxide
Authors: Kuno Hideyuki , Takahashi Kyoko , Shibagaki Makoto , Shimazaki Kazuko , Matsushita Hajime
Published: July 2006

The oxidation of secondary alcohols with ketones was carried out by catalysis with hydrous zirconium(IV) oxide. In the batch reaction system, the oxidation proceeded efficiently to give the corresponding ketones, except for some secondary alcohols. On the other hand, all of the secondary alcohols were efficiently converted to the corresponding ketones in the flow oxidation system. The influence of the hydrogen acceptor on the oxidation rate was investigated by the use of several ketones, and the oxidation rate was influenced by the electron density and steric hindrance around the carbonyl group. The dependence on the reaction temperature was also investigated in the flow reaction system.
Effect of Bond-Length Alternation on the Aromaticity of Benzene
Authors: Aihara Jun-ichi
Published: July 2006

Dewar-de Llano PPP-SCF-MO calculations were performed to examine the effect of bond-length alternation on the σ and π frames of benzene. It was confirmed that the equalization of the CC bond lengths in benzene was caused primarily by a high degree of aromaticity. Benzene still is highly aromatic even if it is deformed artificially. Adiabatic and vertical resonance energies were defined for this compound.
General and Highly Efficient Syntheses of m-Fluoro Arenes Using Potassium Fluoride-Exchange Method
Authors: Suzuki Hiroshi , Yazawa Naoto , Yoshida Yasuo , Furusawa Osamu , Kimura Yoshikazu
Published: July 2006

Tetraphenylphosphonium bromide was found to be a suitable catalyst for the reaction of m-nitroaryl derivatives carrying cyano, nitro, chlorocarbonyl, trifluoromethyl, and chlorosulfonyl groups with potassium fluoride in the presence of a stoichiometric amount of phthaloyl dichloride, giving the corresponding m-fluoro aromatic derivatives in good yields. The catalyst was also found to be efficient for the fluorodesulfonylation of m-(fluorosulfonyl)aryl derivatives to afford m-fluoro arenes by the use of a reaction-distillation technique.
Studies of the Acidity and Ionic Conductivity of Silica-Supported Heteropoly Compounds. III. Paramagnetic Species Involved in the Dehydration Reaction on Supported 12-Molybdophosphoric Acid and Its Salts
Authors: Ohtsuka Reiji , Kobayashi Jun-ichi
Published: July 2006

ESR studies on the dehydration reaction of t-butyl alcohol have been carried out while trying to characterize 12-molybdophosphoroc acid (H3PMo12O40) and its salts supported on silica. In H3PMo12O40 supported on silica ESR spectra showed three signals due to molybdenum(V) with three different surroundings: at the interface near the silica support, at the outer surface of the H3PMo12O40 layer and in the bulk of H3PMo12O40. For K3PMo12O40 supported on silica, crystalline K3PMo12O40 is formed on silica, even at low loadings. The ESR spectra of partially potassium-substituted catalysts is also examined.
Synthesis of Dimethylamino Terminated Poly(tetrahydrofuran) and Adhesion Property of Poly(tetrahydrofuran) Ionene Prepared Therefrom
Authors: Kohjiya Shinzo , Ohtsuki Tohru , Yamashita Shinzo , Taniguchi Masaharu , Hashimoto Tamotsu
Published: July 2006

In order to establish the polymerization conditions for the synthesis of bifunctional dimethylamino group terminated poly(oxytetramethylene) (AT-PT), living cationic polymerization of tetrahydrofuran by trifluoromethanesulfonic anhydride was carried out. Especially, factors determining the molecular weight were investigated. The polymerization enabled us to prepare monodispersed AT-PTs having molecular weght between 2000 and 10000. The resultant AT-PTs were bifunctional, i.e., each molecule contains two dimethylamino groups. From AT-PT and dihalide, poly(oxytetramethylene) ionene (PTI) was synthesized in a thin film form. Tensile properties of the PTI films revealed that the films were very tough and elastic. PTI was also found to have high peel strength towards the Bakelite surface. The peel strength increased with the increase of cationic site on PTI main chains, i. e., with the decrease of molecular weight of AT-PT. PTI also had a high permeability of moisture due to the presence of ionic sites. From these results, PTI can be a promising adhesive material for some biomedical application.
Molecular Rotational Potentials in Solid Halogenated Benzenes: C6Cl6, sym-C6Cl3F3, and C6F6
Authors: Nakamura Nobuo , Yoshino Hiroshi
Published: July 2006

In a previous paper which examined the molecular rotation in sym-C6Cl3F3 crystal by the 35Cl NQR an unrealistically long activation parameter, τ0, for the molecular rotation was obtained by assuming the three-fold molecular uniaxial reorientation. In order to examine the reason for such unacceptable result the relaxation time (T1) data were reanalyzed with the help of the computer experiment which calculates the rotational potential function for each molecule in the crystal lattice. The computation was carried out using the 6-exponential type interatomic pair potential functions. It was found that the potential for the plane molecular rotation in the hexagonal unit cell is non-sinusoidal and has, in addition to the most stable orientation, an extra minimum where the molecules can stay for a finite time at moderately high temperatures. The rotational potential thus obtained was used successfully to reanalyze our previous T1 data for this material. 35Cl NQR T1’s were measured for C6Cl6 crystal and analyzed using anisotropic rotational potentials. The analysis predicted possible disordered structure of this material. In the case of C6F6 it was confirmed that the in-plane rotation of two crystallographically inequivalent molecules can be excited with different activation energies from each other, being consistent with the previous fluorine NMR work.
Preparative Method of Fine Powder of Yttrium(III) Oxide by Thermal Decomposition of NH4Y(C2O4)2·H2O Fine Crystals Obtained by New Reaction of Yttrium(III) Hydroxide Slurry with Oxalic Acid Solution
Authors: Minagawa Yukinori , Yajima Fumikazu
Published: July 2006

A fine powder of yttrium (III) oxide used for an additive of new ceramics, such as Si3N4, ZrO2 etc, has been obtained by thermal decomposition (at 750°C for 1.5 h) of NH4Y(C2O4)2·H2O prepared by the reaction of yttrium hydroxide slurry and an oxalic acid solution. This process has facilitated a scale-up for the production of NH4Y(C2O4)2·H2O fine crystals, resulting in low production costs. The formation mechanism of the crystals via Y(OH3) slurry is discussed.
Magnetic Field Effects on the Intramolecular Photoreaction of n-Alkyl Anthraquinone-2-carboxylates
Authors: Tanimoto Yoshifumi , Uehara Megumu , Takashima Masanobu , Itoh Michiya , Hiramatsu Mitsuo , Nakagaki Ryoichi , Watanabe Takeshi , Nagakura Saburo
Published: July 2006

In the photoreaction of n-alkyl anthraquinone-2-carboxylates, AQ-n, magnetic field effects were observed in the decay of biradicals, the formation rate and the yield of cage products and the disappearance yield of AQ-n. The results are interpreted in terms of the radical pair mechanism. Chain length dependence of the disappearance yield indicates that singlet-triplet energy degeneracy of biradicals occurs when n>10.
Crystal and Electronic Structures of (BEDT–TTF)2[MHg(SCN)4](M=K and NH4)
Authors: Mori Hatsumi , Tanaka Shoji , Oshima Masashi , Saito Gunzi , Mori Takehiko , Maruyama Yusei , Inokuchi Hiroo
Published: July 2006

The crystal structures of (BEDT–TTF)2[MHg(SCN)4] (M=K at 298 and 104 K and M=NH4 at 298 K) were determined by X-ray analyses. A donor layer and an anion sheet stack alternately along the b-axis. The packing pattern of the donor is close to α-phase, while an anion sheet constructs a thick two-dimensional polymer plane parallel to (010). The linkage of (Remark: Graphics omitted.) (or NH4) (Remark: Graphics omitted.) in an anion sheet is very unique. The band structure calculation indicates both a closed and an open Fermi surfaces, resembling that of κ-(BEDT–TTF)2[Cu(NCS)2].
Mechanism of Combustion Reactions in Hydrogen–Air Premixed Flames
Authors: Fukutani Seishiro , Kunioshi Nilson , Jinno Hiroshi
Published: July 2006

Simulation was performed by use of a chemical kinetic model built for flat hydrogen–air premixed flames in order to investigate the combustion mechanism taking place in flames through a wide range of equivalence ratio. The following results were obtained: the flame zone of the stoichiometric flame can be considered as having two different regions; the low-temperature region has, furthermore, three parts differing in reaction mechanism; since the reactions cannot proliferate hydrogen atoms by themselves in the low-temperature region, the acceleration of the reactions is necessarily governed by the hydrogen atoms diffused from the flame front; in the high-temperature region, the reactions produce an excess of hydrogen atoms which activate the reactions in this region or diffuse toward the low-temperature region; lean hydrogen flames possess smaller burning velocity than that of rich flames because the reactions in the low-temperature region have less reproducibility of hydrogen atoms.
Photochemically Induced Single Electron Transfer Reactions of Benzils with Allylstannane. Direct Observation of Reactive Intermediates by ESR Method
Authors: Maruyama Kazuhiro , Matano Yoshihiro
Published: July 2006

Although the photochemically induced reaction of benzil with allyltrimethylstannane in benzene afforded α-allylbenzoin as a major product, benzil did not react thermally with the same reagent. An ESR observation disclosed that the benzil anion radical ion-paired upon contact with trimethylstannyl cation (BSnMe3) was generated during irradiation. Its structure was confirmed by the detection of satellite signals arising from tin isotopes. Moreover, a triplet radical pair was also observed during the photolysis of a solid solution containing benzil and allylstannane at 77 K. This reaction proceeded via a single electron transfer from allylstannane to photoexcited benzil, followed by a cleavage of the C–Sn bond of the allyltin cation radical. Ultimately, a radical pair composed of BSnMe3 and the allyl radical was formed and their coupling gave α-allylbenzoin as an isolated product.
Crystal Structure of Potassium 2,2′-(2,5-Cyclohexadiene-1,4-diylidene)bis[propanedinitrile]-1,4,7,10,13,16-hexaoxacyclooctadecane, [K+(“18-Crown-6”)]TCNQ−
Authors: Nogami Takashi , Morinaga Minoru , Mikawa Hiroshi , Nakano Hideyuki , Horioka Miyako , Horiuchi Hiroyuki , Tokonami Masayasu
Published: July 2006

The crystal structure of the title complex was determined by an X-ray diffraction method. The potassium ion is coordinated by six oxygens of a crown ether and two cyano-nitrogens of two TCNQ anion radicals. Both the crown ether dimer and the TCNQ dimer are arranged alternately in the solid.
Acidity and Catalytic Activity of Zirconium and Titanium Sulfates Heat-Treated at High Temperature. Solid Superacid Catalysts
Authors: Arata Kazushi , Hino Makoto , Yamagata Nobutsugu
Published: July 2006

Acidity and catalytic activity of Zr(SO4)2 and Ti(SO4)2 calcined at 500–800°C were studied. The products obtained by calcination at 725°C for Zr(SO4)2 and at 625°C for Ti(SO4)2 showed the highest activity for the cracking of cumene among samples calcined at other temperatures; the former showed an acid strength of −13.16<H0≤−12.70 and the activity for the reaction of pentane.
Structural Phase Transition and Electrical Conductivity of the Perovskite CH3NH3Sn1-xPbxBr3 and CsSnBr3
Authors: Yamada Koji , Kawaguchi Hiroshi , Matsui Takashi , Okuda Tsutomu , Ichiba Sumio
Published: July 2006

A series of solid solutions, CH3NH3Sn1−xPbxBr3 (x=0–1), having cubic perovskite structures was obtained by solid-state reactions. The 119Sn Mössbauer spectra for x<0.4, however, indicated that the tin environment was considerably distorted from a regular octahedron at 110 K. On the other hand, a single Lorentzian spectrum having a large isomer shift was observed for x>0.7, suggesting the presence of a regular SnBr6 octahedra in the perovskite CH3NH3PbBr3 matrix. The high electrical conductivity of the perovskite CsSnBr3 drastically decreased upon the replacement of the cation by CH3NH3 and the central metal by Pb. This behavior suggests that both the infinite linear chain (–Br–Sn(Pb)–Br–) and its bond length have significant importance regarding electrical conductivity.
Regioselective Condensation of Ethynyl Vinyl Ketone or 2-Propynyl Ether Derivatives with Silyl Enol Ethers Catalyzed by Trityl Perchlorate
Authors: Mukaiyama Teruaki , Matsui Shigekazu , Homma Koichi , Kobayashi Sh\={u}
Published: July 2006

In the presence of a catalytic amount of trityl perchlorate, ethynyl vinyl ketone derivatives regioselectively react with silyl enol ethers to afford the corresponding Michael adducts in high yields. 2-Propynyl ether derivatives also react with silyl enol ethers in the presence of a catalytic amount of trityl perchlorate, to give the corresponding adducts in high yields. In the case of the reaction with 2-propynyl ether derivatives, regioselectivities were apparently different between two silylated nucleophiles, silyl enol ethers of ketones and ketene silyl acetals.
Reaction of a Thioaminyl Diradical with 7,7,8,8-Tetracyanoquinodimethane (TCNQ). The Formation of a Cyclophane Compound
Authors: Miura Yozo , Ohana Tsuguyori , Kunishi Teruo
Published: July 2006

The reactions of thioaminyl mono- (MONOR) and diradicals (DIR) with 7,7,8,8-tetracyanoquinodimethane (TCNQ) have been investigated. The reactions of TCNQ with MONOR gave 1:2 adducts of TCNQ and MONOR in 85–88% yields, while the reaction with DIR afforded either a cyclophane compound (77%), or an alternating polymer of TCNQ and DIR (59 wt%), dependent on the structures of DIR.