bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isotope Effects in the p-Tolylation of Pyridine
Authors: Nakabayashi Takeshige , Horii Toyokazu , Kawamura Shunichi , Abe Yasuo 
Published: July 2006

Abstract
p-Toluoyl peroxide, p-iodotoluene, and di-p-tolyl sulfone, sulfoxide, and sulfide were photolyzed in an equimolar pyridine-pyridine-d5 mixture to give rise to isomeric p-tolylpyridines (α,β, and γ) and their deuterated compounds. Isotopic distribution ratios (YH/YD) in the isomeric products were determined to be slightly larger than unity.
The Reaction of Dibenzylthiocarbamoyl Chloride with Sodium Nitrite
Authors: Nakajima Masayuki , Herget Rose Ann , Anselme Jean-Pierre 
Published: July 2006

Abstract
The reaction of dibenzylthiocarbamoyl chloride with sodium nitrite in acetonitrile at room temperature yields N-nitrosodibenzylamine, dibenzylcarbamoyl chloride, bis(dibenzylcarbamoyl) disulfide, benzaldehyde, and benzyl isothiocyanate; possible mechanisms for the formation of these products are suggested.
Determination of Thermodynamic Properties of Boehmite from its Solubility Data in NaOH Solutions
Authors: Chang Byong-Tae 
Published: July 2006

Abstract
Thermodynamic properties of boehmite in alkaline pH range are determined by applying the extended Debye-Hückel theory to its solubility data in NaOH solutions. When log(Ks/aw2), where Ks=mHmA1 and aw is the activity of the water in NaOH solutions, is plotted against a Debye-Hückel function of ionic strength (I), I1⁄2⁄(1+Bta1I1⁄2), at a given temperature, the curve approaches gradually the theoretical Debye-Hückel limiting slope (2At) with decrease in the ionic strength, and at high ionic strength it deviates positively from the straight line. Under the assumption of the same ionic size parameters for OH− and Al(OH)4− ions, the ionic solubility product, Ks°=aHaA1⁄aw2, for boehmite is given by following equations in the temperature range from 80 to 250 °C: log Ks°=−2663⁄T−5.71 (Case 1) or log Ks°=−2764⁄T−5.45 (Case 2). From a comparison of the temperature dependences of Ks° for boehmite and gibbsite, a transition temperature between the two alumina hydrates was calculated to be 60±3 °C.
Effect of Surfactant Micelles on the Rate of Reaction of Tetranitromethane with Hydroxide Ion
Authors: Harada Tsuyoshi , Nishikido Nagamune , Moroi Yoshikiyo , Matuura Ryohei 
Published: July 2006

Abstract
The rates of trinitromethanide anion formation by the reaction of tetranitormethane with hydroxide ion were measured in the presence of anionic, cationic and nonionic surfactant micelles in aqueous solutions. Using the analytical approach which takes into consideration the distribution of hydrophobic reactants among micelles, k1 (a second-order rate constant on micelles associated with one reactant molecule) and K1/N(K1: an association constant of the reactant with micelles having no reactant, N: an aggregation number of surfactant molecule in a micelle) were estimated. The anionic surfactant exhibited no effect on the reaction rate. In the case of cationic surfactants, both k1 and K1 values increased not only with alkyl chain length but also with hydrophobicity of the surfactants. In the case of nonionic surfactants, an increase of alkyl chain length with a given oxyethylene unit resulted in an increase in the k1 values, while an increase of oxyethylene group with the fixed alkyl chain length resulted in an appearance of the maximum k1 value. From temperature dependence of the reaction rate, a stabilization of the activated complex could be explained by an electrostatic interaction of the complex with the charged micellar surface. It was also found from the analytical approach that the distribution of tetranitromethane among micelles used in the present experiment could be approximated by the Poisson distribution.
Raman Spectra of a Compound under Inversion Motions. II. N-Methylpiperazine
Authors: Fukushima Kunio , Takahashi Hiromichi 
Published: July 2006

Abstract
Raman spectra of N-methylpiperazine in proton donors and acceptors were measured. Forms of stable conformers in the donors and the acceptors were studied by comparison of the Raman spectra and normal vibration calculations. A conformational change of the molecule in the donors was found, suggesting the change of valence state of nitrogen atom, which is caused by hydrogen bonding.
Studies on Room Temperature Phosphorometric and Delayed Fluorometric Analysis. I. Delayed Fluorometric Analysis of Porphyrin Derivatives
Authors: Onoue Yoshiaki , Hiraki Keiz\={o} , Nishikawa Yasuharu 
Published: July 2006

Abstract
The spectral characteristics and its application to measurement of porphyrins were investigated by use of room temperature phosphorometry. Certain porphyrin compounds adsorbed on filter paper exhibit intense E-type delayed fluorescence. This could be utilized for the determination of porphyrin derivatives.
Kinetics and Mechanism of Cobalt(II) Incorporation into meso-Tetra(4-pyridyl)porphine in Acetic Acid
Authors: Funahashi Shigenobu , Saito Keiji , Tanaka Motoharu 
Published: July 2006

Abstract
The kinetics of reactions of meso-tetra(4-pyridyl)porphine (H2TPyP) with cobalt(II) acetate and cobalt(II) nitrate was studied in acetic acid spectrophotometrically. The rate of cobalt incorporation into H2TPyP is first-order in H2TPyP. The conditional first-order rate constants are expressed as follows: for the cobalt(II) acetate system k0(Co)=K[Co(OAc)2]0(1+K[Co(OAc)2]0)−1(k1+k2[Co(OAc)2]0), where at 25 °C K=(5.5±2.0)×104 kg mol−1 (ΔH=−36±15 kJ mol−1, ΔS=−30±30 J mol−1 K−1), k1=(6.3±0.5)×10−5 s−1 (ΔH\eweq=89±8 kJ mol−1, ΔS\eweq=−27±15 J mol−1 K−1), and k2=(1.17±0.05)×10−1 kg mol−1 s−1 (ΔH\eweq=75±3 kJ mol−1, ΔS\eweq=−11±8 J mol−1 K−1); for the cobalt nitrate system k0(Co)=K1[Co(NO3)2]0(1+K1[Co(NO3)2]0)−1(k1+k2[Co(NO3)2]0+k3K2[Co(NO3)2]02), where at 25 °C k1=(5.1±0.5)×10−5 s−1, k2=(2.0±0.1)×10−1 kg mol−1 s−1, K1=(7.2±2.0)×104 kg mol−1, and k3K2=(1.6±0.15)×102 kg2 mol−2 s−1. Formation constants of sitting-atop complexes were determined dynamically. Mechanisms are proposed for metal ion incorporation and some discussions are made on the difference in the reactivities of acetate and nitrate of cobalt(II) in acetic acid.
The Photochemistry of the Host-Guest Complex. V. The Effect of the Sodium Ion on the Photoreaction of Benzil Derivatives with a Crown Ether Moiety
Authors: Hirano Hideki , Kurumaya Katsuyuki , Tada Masaru 
Published: July 2006

Abstract
The photolysis of 4′-(2-phenyl-1,2-dioxoethyl)benzo-15-crown-5 in benzene containing 1-dodecanethiol gives benzaldehyde and 4′-formylbenzo-15-crown-5. The formation of the aldehydes was inhibited by the sodium ion, whereas the photolysis of 1-(3,4-dimethoxyphenyl)-2-phenylethanedione was not inhibited by the sodium ion. This inhibition must be due to the decrease in the formation of benzoyl radicals from the triplet excited state of the crown ether derivative. The salt effect was discussed on the basis of the spectral data.
Synthesis of Oligoinosinates with 2′–5′ Internucleotide Linkage in Aqueous Solution Using Pb2+ Ion
Authors: Sawai Hiroaki , Ohno Masaji 
Published: July 2006

Abstract
Oligoinosinates up to a pentamer were synthesized by the polymerization of inosine-5′-phosphorimidazolide in aqueous solution using Pb2+ ion. 2′–5′ Internucleotide linkage was preferentially formed. The yields of the 2′–5′ linked dimer, trimer, and tetramer were 14.8, 4.5, and 1.6%, respectively. A small amount of linkage isomers of oligoinosinates with 3′–5′ linkage was obtained. The products were characterized by sequential enzyme tests.
Effects of β-Cyclodextrin on Fluorescence Quenching of Sodium 1-Pyrenesulfonate by Aniline in Aqueous Media
Authors: Kobashi Harumichi , Takahashi Masatoshi , Muramatsu Yasuyoshi , Morita Toshifumi 
Published: July 2006

Abstract
β-Cyclodextrin added to the fluorescence quenching system of the title compounds has two effect, depression on dynamic quenching and binding between the fluorescer and quencher causing rapid quenching.
The Photochemical Reaction of Benzo[c]cinnoline. IV. Comments on the Mechanism of 2,2′-Diaminobiphenyl Formation
Authors: Inoue Hiroyasu , Hiroshima Yukimi , Sakai Toshihiko , Sakurai Tadamitsu , Fukuda Norio 
Published: July 2006

Abstract
In order to determine the mechanism of 2,2′-diaminobiphenyl formation from benzo[c]cinnoline, effect of aldehyde on the reaction was examined. It is proposed that ethanal, which was generated from ethanol in the initial photoreduction, formed an adduct with 5,6-dihydrobenzo[c]cinnoline, and that the resulting adduct participated in the subsequent photo-induced 2,2′-diaminobiphenyl formation.
Use of Propagators in the Hückel Model. III. Stability and Reactivity
Authors: Ohmae Takayuki , Nishikawa Kiyoshi , Deguchi Kisaburo , Aono Shigeyuki 
Published: July 2006

Abstract
The propagator approach is applied to the problems of chemical reactivity and stability. Subjects discussed are the ring closure and opening reactions, the Diels-Alder reaction and sigmatropic reaction for reactivity; the aromaticity, two ring compounds (such as naphthalene and azulene), and benzenoid hydrocarbons (such as anthracene and phenanthrene) for stability. Results are given in analytical formulas.
Electron Spin-Spin Interaction in Excited Triplet States of Aromatic Hydrocarbons with a Trigonal Symmetry Axis
Authors: Higuchi Jiro 
Published: July 2006

Abstract
Zero-field splitting (ZFS) parameters of benzene, triphenylene, and coronene molecules in their lowest and second excited triplet states are calculated from the electron spin-spin interaction using semi-empirical self-consistentfield π-electron molecular orbitals. The results show that in obtaining a good agreement of the evaluated ZFS parameters with the experimental values the selection of the basis functions in LCAO-MO’s with zero-differential overlap is actually important. The ZFS parameters in some distorted structures are also calculated.
The Formation of Amino Acids by the Reactions of Singlet NH with Several Carboxylic Acids
Authors: Tsunashima Shigeru , Kitamura Takashi , Sato Shin 
Published: July 2006

Abstract
The photolysis of hydrogen azide was studied in liquid acetic acid, propionic acid, and isobutyric acid at room temperature. The formation of amino acids was confirmed by the color reactions with ninhydrin and with chromotropic acid and by the NMR spectra. From the propionic acid, α- and β-alanine were formed in the ratio of 1.5. In the case of isobutyric acid, α- and β-aminoisobutyric acids were formed in the ratio of about 5. These results are explained by the insertion reaction of NH(a1Δ) into the C–H bonds of carboxylic acids.
1H NMR Studies on the Interactions of Acyclic Polyethers with Dimethyltin Bichloride in Aromatic Solvents
Authors: Otera Junzo , Shiomi Tadashi , Murakami Kazuhiko , Kawasaki Yoshikane 
Published: July 2006

Abstract
The interactions between various acyclic polyethers, RO(CH2CH2O)nR′(R, R′=CH3, Ph), and dimethyltin dichloride (DMTC) in aromatic solvents have been studied by means of 1H NMR spectroscopy. On the basis of a continuous variation method, the formation of the 1 : 1 complexes between glymes, CH3O(CH2CH2O)nCH3(n=2, 3, 4), and DMTC was revealed in benzene. The 2J(119Sn–CH3) values suggested distorted trans-octahedral configurations for these complexes. From the statistical consideration of stability constants, it was found that the coordination occurred virtually through neighboring two oxygen atoms in these complexes. DMTC gave the complexes of both 1 : 1 and 1 : 2 glyme/DMTC stoichiometry with glymes (n=5, 6) in benzene and with all glymes employed here in toluene and 1-chloronaphthalene. Coexistence of 1 : 1 and 1 : 2 species was also encountered for PhO(CH2CH2O)nCH3 (n=3, 4, 5), whereas no appreciable interaction was observed between PhO(CH2CH2O)nPh (n=2, 3, 4) and DMTC. On the basis of these observations, the additional formation of the 1 : 2 complexes was assumed to be caused by the bulkiness of polyethers.
Reactions of 5,6-Dilithioacenaphthene-N,N,N′,N′-Tetramethyl-1,2-ethanediamine Complex with α-Diketones. I. cis-Directing 1:1 Cyclic Additions with Acyclic and Cyclic α-Diketones and Related Compounds
Authors: Tanaka Norio , Kasai Toshiyasu 
Published: July 2006

Abstract
The title complex (3) is readily generated from 5,6-dibromoacenaphthene with butyllithium and the diamine in ether at −10–0 °C. The reaction of 3 with biacetyl gave cis-1,2,5,6-tetrahydro-1,2-dimethylcyclopent[fg]acenaphthylene-1,2-diol but no trans-isomer, whereas the reaction of pyracenequinone (PYQ) with methylmagne-sium bromide gave both the cis- and trans-dioh. The reactions of 3 with acenaphthenequinone and PYQ also gave cis-diols. On treatment with phenylboronic acid, these cis-diols quantitatively yielded the corresponding cyclic esters. The diols and their derivatives tend to form crystalline molecular compounds with solvent molecules. The stereoselectivity of the cyclic addition between 3 and the acyclic α-diketone can be best explained in terms of five-membered chelate-ring formation in a transition state.
Reactions of 5,6-Dilithioacenaphthene-N-N,N′,N′-Tetramethyl-1,2-ethanediamine Complex with α-Diketones. II. Competitive Oxophilic and Carbophilic Additions and Redox Reactions
Authors: Tanaka Norio , Kasai Toshiyasu 
Published: July 2006

Abstract
The reaction of the title complex (3) with benzil did not give the 1 : 1 cyclic addition product expected, but gave 5,6-dibenzoylacenaphthene, 5-(1-hydroxy-2-oxo-1,2-diphenylethyl)-6-(2-oxo-1,2-diphenylethoxy)acenaphthene (5), 5-benzoyl-6-(1-hydroxy-2-oxo-1,2-diphenylethyl)acenaphthene, benzoin, and benzilic acid. Compound 5 suggests a new type of oxophilic addition accompanied by a carbophilic addition. The reaction of 3 with 9,10-phenanthrenequinone in a 1 : 1 molar ratio gave both the oxidative homo-coupling product of 3, 1,2,7,8-tetrahydrodicyclopenta[cd : lm]perylene, and the hydroquinone dianion, which was converted into 9,10-diacetoxyphenanthrene on acetolysis. The differences in the reaction modes between 3 and α-diketones can basically be understood in terms of the redox potentials and the steric factors of the α-diketones.
Diisobutylaluminum 2,6-Di-t-butyl-4-methylphenoxide. Novel Stereoselective Reducing Agent for Prostaglandin Synthesis
Authors: Iguchi Sadahiko , Nakai Hisao , Hayashi Masaki , Yamamoto Hisashi , Maruoka Keiji 
Published: July 2006

Abstract
In an effort to explore the selective reducing agents suitable for prostaglandin synthesis, diisobutylaluminum 2,6-di-t-butyl-4-methylphenoxide (1) is found to be among the best. Reduction of the C-15 ketone with 1 in toluene at −78 °C produced the desired 15S-alcohol in 95% yield with 92% stereoselectivity. The present procedure is suitable for the synthesis of prostaglandin derivatives and related polyfunctional natural products as shown in the conversion of PGE2 methyl ester to PGF2α methyl ester in 95% yield and 100% selectivity.
NMR Studies of Picolyl-type Carbanions. V. 7Li and 13C Spectra of Picolyl-type Anions with Lithium as a Counter Ion
Authors: Konishi Kazuyori , Yoshino Akihiro , Katoh Morimatsu , Takahashi Kensuke , Kawada Yuzo , Sugawara Tadashi , Iwamura Hiizu 
Published: July 2006

Abstract
The 7Li and 13C NMR spectra have been observed for picolyl-type anions with lithium as a counter ion in polar solvents. With reference to the observed chemical shifts, it is concluded that these lithium salts are present in THF as tight ion pairs in which the anion-cation interaction takes place mainly at the ring nitrogen. Thus, the picolyl-type anions are characterized by their ion-pair structures.
Dissociation of Micelles and Intermicellar Concentrations of Aqueous Solutions of Calcium and Sodium Decyl Sulfates
Authors: Koshinuma Masakatsu 
Published: July 2006

Abstract
Activities of the surfactant ions and the counterions were calculated from the electromotive forces of concentration cell with ion-exchange membranes for the aqueous solutions of calcium (Ca(DeS)2) and sodium (NaDeS) decyl sulfates. Moreover, the mean activities and the activity coefficients were obtained. From these activities, the valence effects of the counterions on the dissolved state of micellar solutions were studied. The following results were obtained: (1) The mean activities were not constant, but increased with the increase in the concentration of the two surfactants above the CMC; the slope of curve of the mean activity for Ca(DeS)2 against its concentration was smaller than that for NaDeS. (2) The CMCs were 6.4 for Ca(DeS)2 and 32.8 mmol dm−3 for NaDeS, respectively. (3) For the mechanism of micelle formation, the phase separation model was set up in both cases. (4) From this model, the degrees of dissociation of the micelles were calculated as 0.12 for Ca(DeS)2 and 0.28 for NaDeS, respectively. (5) The intermicellar concentrations of the Ca2+, the Na+, and the decyl sulfate (DeS−) ions were calculated; those of the counterions increased but those of the DeS− ions decreased with the increase in their surfactant concentrations. Moreover, those of the DeS− for Ca(DeS)2 changed slowly while those for NaDeS changed steeply.
A Conductance Study of Alkali Metal Ion–18-Crown-6 Complexes in N,N-Dimethylformamide
Authors: Takeda Yasuyuki 
Published: July 2006

Abstract
The formation constants, KML+, for 1 : 1 complexes of 18-crown-6 (18C6) with alkali metal ions (Na+, K+, Rb+, and Cs+) and the limiting ionic molar conductivities, λ°, of the complexed cations in N,N-dimethylformamide have been determined conductometrically at 25 °C. The KML+ sequences of the alkali metal ions with 18C6 are K+&gt;Rb+&gt;Cs+&gt;Na+. The stabilities and selectivities on complexation are governed by the solvent medium and the relative sizes of the cation and the 18C6 cavity. The λ° values of the 18C6 complexes with the alkali metal ions are all approximately equal except for Cs+, suggesting that, in the cases of Na+, K+, and Rb+, the charge of the alkali metal ion trapped in the 18C6 cavity is effectively screened by 18C6, while this is not true in the case of Cs+. The ratio of the size of the alkali metal ion to that of the 18C6 cavity appears to be an important factor in determining the magnitude of λ° for alkali metal ion-18C6 complexes.
Uncatalyzed Chemical Oscillatory Behavior in the Oxidation of Catechol with Acidic Bromate Solution
Authors: Nair Punnappillil K R , Mittal Archana , Srinivasulu Kotra 
Published: July 2006

Abstract
A temporal oscillatory behavior of the redox potential in the oxidation of catechol with potassium bromate in sulfuric acid medium is reported.
Unusual Transposition of the Carbonyl Group in the Reduction of 2-Amino-1-indanone
Authors: Kim Jack C 
Published: July 2006

Abstract
The catalytic reduction procedure of 2-amino-4,5-dimethoxy-1-indanone hydrochloride gave a major reduction product of 2-amino-4,5-dimethoxyindan hydrochloride, along with a small amount of a rearranged 4,5-dimethoxy-2-indanone. The isolated intermediate, 2-amino-4,5-dimethoxy-1-indanol hydrochloride yielded exclusively 4,5-dimethoxy-2-indanone under catalytic reaction conditions (acid treatment). The unusual transformation product was verified on the basis of IR, NMR and the result of elemental analysis. A plausible mechanism for the rearrangement is discussed.
The Splitting of the ESR Signal of Di-t-butyl Nitroxide Solubilized by Micellar Solutions
Authors: Isshiki Shojun , Uzu Yuhei 
Published: July 2006

Abstract
In a hexadecyltrimethylammonium bromide solution containing the stable micelle, a solubilized di-t-butyl nitroxide facilitated the partial resolution of the high-field line of the ESR spectrum, which can be associated with the radical in aqueous and micellar phases. Further analysis of the lineshape was made as a function of the surfactant concentration or the temperature.
Electrochemical Behavior of Alkoxo-bridged Binuclear Copper(II) Complexes with N,N-Dialkyl-N′-(hydroxyalky)alkanediamine
Authors: Aihara Makoto , Kubo Yoshiko , Nishida Yuzo , Kida Sigeo 
Published: July 2006

Abstract
The alkoxo-bridged binuclear copper(II) complexes with N,N-dialkyl-N′-(hydroxyalkyl)alkanediamine were investigated by electrochemical methods. The binuclear complexes exhibited two non-separable sequential, oneelectron steps, the half-wave potentials of which were almost identical, in N,N-dimethylformamide. On the other hand, the complexes gave two distinctive one-electron reduction waves in acetonitrile.
Preparation of Sephadex Derivatives with Optically Active Groups and Column-chromatographic Application to the Resolution of Some Cobalt(III) Complexes
Authors: Fujita Miho , Sakano Masanobu , Yoshikawa Yuzo , Yamatera Hideo 
Published: July 2006

Abstract
Optically active cation-exchangers were newly prepared as Sephadex derivatives derived from l-alanine, l-valine, l-aspartic acid, and l-threonine. They were applied to the column-chromatographic resolution of some cobalt(III) complexes, partial resolution being attained.
N-Sulfonylaminyls. The Isolation of Dimers and Their Properties
Authors: Miura Yozo , Nakamura Yuji , Kinoshita Masayoshi 
Published: July 2006

Abstract
From the reaction mixtures of sulfonamides [3,5-(t-Bu)2C6H3NHSO2C6H4CH3-p and 3,5-(t-Bu)2C6H3NHSO2CH3] with di-t-butyl diperoxyoxalate, dimers of N-sulfonylaminyls were isolated as pure crystals which, in solution, dissociated into the corresponding N-sulfonylaminyls upon heating to 60 °C.
Ring Monofluorinated Hydroxypyrazoles
Authors: Kagaruki Serry R F , Kitazume Tomoya , Ishikawa Nobuo 
Published: July 2006

Abstract
3-Alkyl(or aryl)-4-fluoro-5-hydroxypyrazoles and their 1-methyl derivatives were prepared by the reaction of methyl α-fluoro-β-alkyl(or aryl)-β-keto esters with hydrazine hydrate or methylhydrazine in ethanol. The reaction of arylhydrazines with α-fluoro-β-keto esters gave only hydrazones which could not be cyclized to pyrazoles.
Removal and Recovery of Organic Pollutants from the Aquatic Environment. VII. Adsorption of Phenol and Carboxylic Acids on Crosslinked Poly(4-vinylpyridine)
Authors: Kawabata Nariyoshi , Higuchi Ichiro , Yoshida Jun-ichi 
Published: July 2006

Abstract
Molecular adsorptions of phenols and carboxylic acids on crosslinked poly(4-vinylpyridine) were studied in comparison with those on various polymeric adsorbents. Enthalpies for the adsorption of phenol on various polymeric adsorbents were evaluated based upon the temperature dependence of the phenol adsorption isotherms. The enthalpy on crosslinked poly(4-vinylpyridine) was close to that on porous poly(styrene-divinylbenzene) resin with no ion exchange functional group, and was much smaller than that on commercial weak base anion exchange resin. The relative adsorption capacities of various polymeric adsorbents for carboxylic acids and substituted phenols indicated that the acid-base interaction as well as hydrophobic interaction between these organic acids and crosslinked poly(4-vinylpyridine) was an important factor in the adsorption.
Magnetic Susceptibility and Crystal Structure of 1,5-Diphenyl-3-(4-chlorophenyl)verdazyl Radical
Authors: Azuma Nagao , Tsutsui Kanji , Miura Yozo , Higuchi Taiichi 
Published: July 2006

Abstract
The magnetic susceptibility of 1,5-diphenyl-3-(4-chlorophenyl)verdazyl (Cl-TPV) has been measured on a powder sample in the temperature region between 1.8 and 80 K. It exhibited a round maximum at 21.0 K; this temperature is the highest among those observed for verdazyl monoradicals. The susceptibility can be well described by the Heisenberg linear chain model; the estimated exchange interaction parameter is J⁄k=−16.4 K. The crystal structure of Cl-TPV has been determined by means of X-ray diffraction. The crystal is orthorhombic, with the space group of Pbca and with a=22.041(5), b=7.166(4), c=21.379(5) Å, and Z=8. The molecules are arranged in a column along the b axis. The exchange interaction has been discussed based on the crystal structure and the spin density distribution.