bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel C5-Substituted 2′-Deoxyuridine Derivatives Bearing Amino-Linker Arms: Synthesis, Incorporation into Oligodeoxyribonucleotides, and Their Hybridization Properties
Authors: Ozaki Hiroaki , Nakamura Akiko , Arai Midori , Endo Masakazu , Sawai Hiroaki 
Published: July 2006

Abstract
2′-Deoxyuridine derivatives bearing several kinds of amino-linker arms at C5 position were synthesized from 5-(methoxycarbonylmethyl)-2′-deoxyuridine and ethylenediamine, 1,6-hexanediamine, or tris(2-aminoethyl)amine. The modified nucleosides were incorporated into oligodeoxyribonucleotides at one or three positions in place of thymidine residues. The thermal stability of the duplexes was investigated. Three incorporations of ethylenediamine or tris(2-aminoethyl)amine at the C5-position increase the duplex stability. The amino-linker arm affected the stability of the duplexes depending on the number of amino groups in the linker arm and the length of the arm. The linker arm improved the nuclease resistance at 5′-side phosphodiester linkage of the modified nucleoside in oligodeoxyribonucleotides.
A Membrane Protein Model: Polypeptides with Four α-Helix Bundle Structure on 5,10,15,20-Tetrakis[2-(carboxymethoxy)phenyl]porphyrin
Authors: Arai Toru , Kobata Keisuke , Mihara Hisakazu , Fujimoto Tsutomu , Nishino Norikazu 
Published: July 2006

Abstract
A novel template for the polypeptide–porphyrin hybrid, 5,10,15,20-tetrakis[2-(ethoxycarbonylmethoxy)phenyl]porphyrin (2) was synthesized in 17% yield. Four protected carboxyl groups are installed in 2 at the ortho-phenyl groups as the anchoring points, to which the N-termini of the polypeptides can be linked after the hydrolysis. Thus, 2 is a new analog of the porphyrin template tetrakis[2-(methoxycarbonyl)phenyl]porphyrin. The atropisomerization of 2 was much more rapid than that of tetrakis[2-(methoxycarbonyl)phenyl]porphyrin: At 353 K, 2 reached their equilibrium within 15 min. Such atropisomeric flexibility of 2 allows the self-organization of the α-helical peptide segments which are connected to 2. After the hydrolyses of the ethyl ester groups of 2, four α-helical 21-peptides, H–(–Gln–Leu–Leu–Gln–Ala–Leu–Ala–)3–NHCH2CH2OH were combined through the amide bonds to yield a new polypeptide–porphyrin hybrid (12). The polypeptide moieties of 12 showed typical α-helix profiles on circular dichroism measurements in methanol–water (3/1, v/v) and in Tris·HCl buffer solution. Thus, the four α-helix polypeptides are considered to fold into a bundle structure on the porphyrin template through the hydrophobic interaction. The circular dichroism spectrum of 12 in methanol showed an induced Cotton effect at the porphyrin region, and the CD band was symmetrically split. The hybrid (12) was also successfully incorporated into the egg yolk lecithin membrane almost quantitatively. When the molar ratio of egg yolk lecithin/12 was 500/1, the α-helix structure of the peptide segments in 12 was completely retained in the vesicles.
Manganese(III)-Mediated Oxidative Radical Cyclization 2. Reaction of 1,1,ω,ω-Tetraarylsubstituted Terminal Alkadienes with Malonamide or Acetoacetamide
Authors: Nishino Hiroshi , Hashimoto Hideaki , Korp James D , Kurosawa Kazu 
Published: July 2006

Abstract
The oxidation of 1,1,6,6-tetraaryl-1,5-hexadienes with manganese(III) acetate in the presence of malonamide gave two types of 5-exo cyclization products, 1-carbamoyl-8-diarylmethylene-3-azabicyclo[3.3.0]octan-2-ones and 3,10-dioxatricyclo[6.3.0.01,5]undecane-2,11-diones, in good to moderate yields. Similar reactions of 1,1,5,5-tetraaryl-1,4-pentadienes or 1,1,7,7-tetraaryl-1,6-heptadienes with malonamide yielded only complex mixtures, except for the formation of a small amount of 3,11-dioxatricyclo[7.3.0.01,5]dodecane-2,12-dione. On the other hand, 1,1,5,5-tetraaryl-1,4-pentadienes reacted with acetoacetamide in the presence of manganese(III) acetate to afford 3-carbamoyl-2-methyl-4-(2-propenyl)-4,5-dihydrofurans and 1,4-pentadienes substituted at the 3-position with acetoacetamide. A similar reaction of 1,1,6,6-tetraaryl-1,5-hexadienes with acetoacetamide gave 8-[acetoxy(diaryl)methyl]-3-oxabicyclo[3.3.0]octan-2-ones, 1-acetyl-8-diarylmethylene-3-azabicyclo[3.3.0]octan-2-ones, and 4-(3-butenyl)-3-carbamoyl-2-methyl-4,5-dihydrofurans. The selectivity of the inter- and intramolecular cyclizations containing the carboxamide moiety of malonamide or acetoacetamide is discussed.
Studies of the Selective O-Alkylation and Dealkylation of Flavonoids. XVIII. A Convenient Method for Synthesizing 3,5,6,7-Tetrahydroxyflavones
Authors: Horie Tokunaru , Kobayashi Takashi , Kawamura Yasuhiko , Yoshida Isao , Tominaga Hideaki , Yamashita Kazuyo 
Published: July 2006

Abstract
In the demethylation of 6-hydroxy-3,4′,7-trimethoxy-5-(tosyloxy)flavone with anhydrous aluminum bromide, the 5-tosyloxyl group was eliminated with bromination to give 8-bromo-3,6,7-trihydroxy-4′-methoxyflavone as the main product. When anhydrous aluminum chloride was used in the demethylation of the acetate, the 5-tosyloxyl group was cleaved prior to the demethylation to give 5,6,7-trihydroxy-3,4′-dimethoxyflavone. Demethylation of 6-hydroxy-4′,5,7-trimethoxy-3-(tosyloxy)flavone and its acetate with the bromide or chloride afforded the 5,6,7-trihydroxyflavone without the cleavage of the 3-tosyloxyl group, but was not suitable for the general synthesis of the 3,5,6,7-tetrahydroxyflavones because of the difficulty in removing the protecting group. Consequently, it was found that the direct demethylation of 3,6-dihydroxy-5,7-dimethoxyflavones with anhydrous aluminum chloride–sodium iodide in acetonitrile was the most useful general method for synthesizing 3,5,6,7-tetrahydroxyflavones. Additionally, the reported structures of two natural flavones were revised.
Calorimetric and 195Pt NMR Studies on Aromatic Ring Stacking between Nucleotides and Platinum DNA Intercalators
Authors: Odani Akira , Sekiguchi Tetsuo , Okada Hisashi , Ishiguro Shin-ichi , Yamauchi Osamu 
Published: July 2006

Abstract
Calorimetric and spectroscopic investigations have been carried out on the stacking interactions between nucleosides or nucleotides (NMP) and platinum DNA intercalators and other planar platinum(II) complexes with heteroaromatic ligands (L). Pt(L)(diamine) (L = 1,10-phenathroline (phen), its methyl and nitro derivatives, 2,2′-bipyridine; diamine = ethylenediamine (en), L-2,3-diaminopropionate) reacts with NMP (=adenosine 5′-monophosphate (AMP), guanosine 5′-monophosphate (GMP), inosine 5′-monophosphate (IMP), cytidine 5′ -monophosphate (CMP); nicotinamide adenine dinucleotide (NAD), adenosine, cytidine) to give the Pt(L)(diamine)–(NMP)n adducts (n = 1, 2) with log K1 = 1.63—3.00 and log K2 = 1.47—2.51 at 25 °C at ionic strength = 0.1 mol dm−3 (NaCl). The 1 : 1 adduct formation mainly depends on the enthalpy change ΔH1° = −6.5 — −26.2 kJ mol−1, and the entropy change (ΔS1° = −38—20 J mol−1 K−1) makes a negative or small contribution. 1H NMR upfield shifts observed for the Pt(phen)(en)–NMP systems have substantiated the presence of stacked adducts in dilute aqueous solution, whereas diquat, a dicationic organic molecule, did not cause appreciable shifts, and hence the adduct formation was negligible. NAD was found to interact with Pt(phen)(en) through the adenine moiety. 195Pt NMR signals of Pt(phen)(en) in water suffered downfield shifts upon addition of NMP, the Δδ1 values being in the order NAD ≥ AMP ≈ GMP &gt; IMP. This indicates that stacking causes an electron density decrease of the Pt(II) center. Linear relationships have been detected between the ΣΔHn° values and the absorption coefficients εn of the difference spectra in the charge transfer region and between ΣΔHn° and 195Pt NMR shift differences Δδn. These observations serve as evidence for the electronic effects of stacking interactions on the stacked rings and the central Pt(II) ion.
High Resolution Solid State NMR in Liquid. IV. 1H NMR Study of Terephthalic Acid Nano-Particles
Authors: Satoh Naoki , Naito Akira , Kimura Keisaku 
Published: July 2006

Abstract
High-resolution 1H NMR spectra of terephthalic acid (TPA) ultrafine particles (UFP’s) were obtained under the conditions of rapid Brownian motion of UFP’s in liquid CCl4 (UFP-NMR method). Six signals were resolved in the range of 6.85 to 7.65 ppm with respect to an tetramethylsilane. These were assigned to aromatic protons, even though only a single signal at 8.15 ppm was obtained from molecular dispersion of TPA in acetone. TPA-UFP dispersions were prepared by a vacuum evaporation technique combined with a cold matrix-isolation method. Particle sizes obtained were ca. 15 nm by a dynamic laser scattering method. The results from UFP-NMR method are discussed in conjunction with those from solid state 1H NMR via a CRAMPS method and with a conventional liquid state NMR of TPA.
Study of the Reaction of Benzoyl Chloride and Sodium Dicarboxylate under Inverse Phase Transfer Catalysis
Authors: Wang Maw-Ling , Ou Chin-Chou , Jwo Jing-Jer 
Published: July 2006

Abstract
The reaction of benzoyl chloride (PhCOCl) and sodium dicarboxylate (R(COONa)2) catalyzed by an inverse-phase-transfer catalyst (IPTC) in the two-phase medium H2O/CH2Cl2 was investigated. Pyridine 1-oxide (PNO) was used as the inverse-phase-transfer catalyst. Ten dicarboxylates, namely oxalate, malonate, maleate, succinate, adipate, nonanedioate, fumarate, phthalate, isophthalate, and terephthalate, were selected for study. In general, the observed mixed products included mono- and bis(benzoyloxycarbonyl) compounds, benzoic anhydride and benzoic acid, depending on the molecular structure of the dicarboxylate ion. Dicarboxylates of four types were classified according to distribution of products. The reaction rate is strongly affected by PhCOCl and R(COONa)2 due to their influence on the distribution of PNO in the organic phase. A mechanistic interpretation of the experimental data is presented.
Theoretical Evaluation of Hyperpolarizability of l-2-Pyrrolidone-5-carboxylic Acid (l-PCA)
Authors: Kitazawa Manabu , Takahashi Mitsuo , Wada Tatsuo , Sasabe Hiroyuki , Nakano Masayoshi , Yamaguchi Kizashi 
Published: July 2006

Abstract
l-2-Pyrrolidone-5-carboxylic acid (l-PCA) is a novel nonlinear optical material with the optical transparent range down to the UV region. l-PCA molecules are hydrogen-bonded to form the three-dimensional network in a crystal. It has been thought that the network of hydrogen bonds influences on the stability of the crystal structure as well as the second-order optical nonlinearity. We have performed the theoretical evaluation of the contributions of the intermolecular hydrogen bonds to structural stability and second-order nonlinearity in the l-PCA crystals by use of the molecular orbital calculation methods. In the calculation of CNDO/S-SECI (singly excited configuration interaction) method, it is shown that the primary contributor to the molecular hyperpolarizability (β) is an nπ → π* transition in the amide moiety of l-PCA molecule. The calculation of intermolecular interaction energies for l-PCA clusters by the ab initio STO-3G method indicates that the hydrogen bonds in the crystal contribute to the stabilization of the crystal structure by −7.8 to −9.1 kcal mol−1 for one hydrogen-bond formation. Furthermore, it is also confirmed by CNDO/S-CHF (coupled Hartree–Fock) calculation that the hydrogen-bonding interactions induce the enhancement of the βXyz value, a unique β component contributing to the nonlinear optical coefficient (d14). On the basis of the calculated β components, d14 can be estimated to be d14 = 0.30 pm V−1 by the oriented-gas model. This value is in good agreement with the experimental result. Therefore, these results verify that the hydrogen bonds between l-PCA molecules contribute not only to the physical and chemical stability of l-PCA crystals but also to the enhancement of β values. This theoretical estimation shows the effectiveness of the hydrogen bonds in second-order nonlinear optical crystals.
The Electrical and Magnetic Properties of a Novel Two-Dimensional Antiferromagnet Based on BEDT–TTF: θ-(BEDT–TTF)2Cu2(CN)[N(CN)2]2
Authors: Komatsu Tokutaro , Sato Hirohiko , Nakamura Toshikazu , Matsukawa Nozomu , Yamochi Hideki , Saito Gunzi , Kusunoki Masami , Sakaguchi Ken-ichi , Kagoshima Seiichi 
Published: July 2006

Abstract
A crystal-structure analysis and a band calculation, as well as conductivity, thermoelectric power, ESR, and static susceptibility measurements were performed on the new BEDT–TTF salt, θ-(BEDT–TTF)2Cu2(CN)[N(CN)2]2. This salt has a unique polymerized anion comprising infinite Cu–N(CN)2–Cu double helices bridged by disordered CN groups. Although the two-dimensional arrangement of crystallographically equivalent BEDT–TTF+0.5 cations provides a two-dimensional closed Fermi surface within the tight-binding approximation, this salt is semiconductive even at room temperature, probably due to a strong electron correlation in this system. A semiconductor–semiconductor transition has been observed around 220 K. Below 220 K the electronic system is represented as a Mott insulator and a two-dimensional Heisenberg antiferromagnet. Rapid decreases in the ESR line width and spin susceptibility below 50 K indicate the existence of an additional magnetic transition.
Separation of Cadmium Salicylate by Solvent Extraction Using Tris(2-ethylhexyl) Phosphate
Authors: Nambiar Dinesh C , Shinde Vijay M 
Published: July 2006

Abstract
Tris(2-ethylhexyl) phosphate (T2EHP) is used for the extraction of cadmium salicylate. The experimental conditions are established and the probable extractable species is ascertained by log D–log C plots. Microgram amounts of cadmium are determined in the Tris(2-ethylhexyl) phosphate phase with 1-(2-pyridylazo)-2-naphthol as the chromogenic agent. The proposed method is used for the separation of cadmium(II) from zinc(II), mercury(II), lead(II), bismuth(III), antimony(III), and thallium(III) and used for the estimation of cadmium in industrial waste water, kidney stone, cigarettes, and alloy samples.
X-Ray Crystal Structures and Chemical Properties of Heterocyclic Azo Compounds Coupled with m-Alkoxyphenols
Authors: Ishizuki Tomosuke , Murakawa Tomoaki , Yamada Tetsuya , Yuchi Akio , Wada Hiroko , Shiro Motoo 
Published: July 2006

Abstract
X-Ray crystal structures have been determined for two compounds obtained by the coupling reaction of 2-pyridinediazonium salt and m-methoxyphenol, viz., 3-methoxy-4-(2-pyridylazo)phenol (1) and 5-methoxy-2-(2-pyridylazo)phenol (2). The 2-pyridylazo and 2-thiazolylazo compounds having o-methoxy and p-hydroxy groups, such as 1, have lower pKa values and lower affinities for or higher selectivities to metal ions than corresponding o-hydroxy isomers. The resulting bis complexes with metal ions show molar absorptivities greater than 105.
Synthesis of 2′,3′-Didehydro-2′,3′-dideoxy Nucleosides from 2′,2′-Bis(phenylthio) Nucleoside Analogs
Authors: Niihata Shigeo , Kuno Hideyuki , Ebata Takashi , Matsushita Hajime 
Published: July 2006

Abstract
2′,3′-Didehydro-2′,3′-dideoxy nucleosides were synthesized from 2′,2′-bis(phenylthio) nucleoside analogs via five-step reactions. The sulfonyl group of the intermediate was removed by a treatment with sodium amalgam.
Mass-Spectrometric Study on Ion-Molecule Reactions of CF3+ with Nitrogen-Containing Benzene Derivatives, Pyridine, Pyrrole, and Acetonitrile at Near-Thermal Energy
Authors: Tsuji Masaharu , Aizawa Masato , Ujita Hiroki , Nishimura Yukio 
Published: July 2006

Abstract
The gas-phase ion-molecule reactions of CF3+ with nitrogen-containing benzene derivatives (C6H5Y : Y = NH2, NO2, and CN), pyridine, pyrrole, and acetonitrile have been studied at near-thermal energy using an ion-beam apparatus. The major product channels are charge transfer for aniline (71.7 ± 0.5%), O− abstraction for nitrobenzene (91.7 ± 0.5%), electrophilic addition leading to initial adduct ions for benzonitrile (97.5 ± 0.8%), acetonitrile (100%), and pyridine (94.8 ± 0.4%), and electrophilic addition followed by HF elimination for pyrrole (80.0 ± 1.4%). The reaction mechanism is discussed based on product ion distributions and theoretical calculations of the energies of reaction pathways.
Synthetic Photochemistry. LXVII. A Total Synthesis of (±)-Hinesol and (±)-Agarospirol via retro-Benzilic Acid Rearrangement
Authors: Hatsui Toshihide , Wang Jin-Jun , Takeshita Hitoshi 
Published: July 2006

Abstract
A mild base-catalyzed retro-benzilic acid rearrangement of a proto-photocycloadduct, formed in highly stereoselective photoaddition of methyl 2,4-dioxopentanoate to 1,5-dimethyl-6-methylene-1-cyclohexene, afforded a spiro[4.5]decenedione derivative. Reductive elimination of the α-dicarbonyl function and C1-homologation furnished (±)-hinesol and (±)-agarospirol.
Preparation of New Nitrogen-Bridged Heterocycles. 39. One-Pot Synthesis of 2H-Pyrano[3,2-a]indolizin-2-one Derivatives
Authors: Kakehi Akikazu , Ito Suketaka , Matsubara Ken 
Published: July 2006

Abstract
Various ethyl 2-(3-cyanoallylidene)- or 2-[3-(ethoxycarbonyl)allylidene]-1,2-dihydropyridin-1-ylacetates were prepared from the reactions of 1-(1-ethoxycarbonylalkyl)-2-methylpyridinium halides with activated ethoxymethylidene compounds in the presence of a base. The treatment of these 2-allylidene-1,2-dihydropyridine derivatives with acetic acid at the reflux temperature gave directly the title compounds in low to moderate yields.
Phase-Transfer Nucleophilic Reactions Using Water-Insoluble Alcohols as Organic Solvents
Authors: Ohtani Noritaka , Inoue Yukihiko , Shinoki Noriyuki , Nakayama Katsuhiro 
Published: July 2006

Abstract
Simple nucleophilic substitutions were done under liquid–liquid phase-transfer reaction conditions using water-insoluble alcohols as organic solvents. The reactions proceeded at considerable rates even in the absence of any catalysts, depending on the alcohol, inorganic salt, and the aqueous concentration of the salts. An addition of single- or double-chained onium salts enhanced the reaction rate almost linearly with the amount of the onium salts. The concentrations of inorgainc salts and water in the alcohol phase were analyzed and the relationship between these concentrations and the observed rate constant was discussed. An interfacial reaction mechanism explains the kinetics of this reaction system better than the conventional ion-pair mechanism assumed by most research using hydrocarbon solvents.
Novel Catalyst Systems for Phenol Synthesis by Vapor Phase Oxidation of Benzoic Acid
Authors: Miki Jun , Asanuma Minoru , Tachibana Yakudo , Shikada Tsutomu 
Published: July 2006

Abstract
Nickel, iron, and cobalt oxides showed excellent catalytic activities for the vapor-phase oxidation of benzoic acid to phenol at the reaction temperature of 400 °C. The combination of these metal oxides, catalyst preparation by precipitation followed by calcination at 800 °C, and addition of Na2O to the catalyst about 1% by weight enhanced the conversion of benzoic acid and the selectivity to phenol.
The structure of precipitation catalyst, Fe/Ni atomic ratio on the catalyst surface and formation of sodium benzoate on the catalyst surface play important roles for the optimization of catalyst activity. The novel catalyst systems could throw a new light on a one-step phenol synthesis from toluene. Appreciable one-pass phenol yield was obtained using a binary catalyst system consisting of V2O5–K2SO4–TiO2 and NiO–Fe2O3–Na2O, in which V2O5–K2SO4/TiO2 worked as a catalyst for toluene oxidation to benzoic acid and NiO–Fe2O3–Na2O functioned as a catalyst for benzoic acid to phenol.
Degradation of Azo Dyes by Sodium Hypochlorite 3. Estimation of the Rate Equation for the Degradation of Orange G and Benzopurpurine
Authors: Kanazawa Hitoshi , Onami Tetsuo 
Published: July 2006

Abstract
Degradation of azo dyes, Orange G and Benzopurpurine, by sodium hypochlorite in water was observed by UV spectroscopy. The observed values of the maximum absorbance in the spectra of the reaction mixture fitted well with the polynomials of the fifth degree in reaction time, t. The initial degradation rate of each dye was obtained easily as the differential coefficient of the functions at time 0. The degradation rate (Rd) of both dyes in the initial stage of the reaction was given by the second-order rate equation, Rd = k[Dye][NaOCl], where k is a rate constant. Apparent activation energies and frequency factors of the degradation were estimated as 20.3 kJ mol−1 and 4.59 × 104 dm3 mol−1 s−1, respectively, for Orange G, and 9.56 kJ mol−1 and 5.78 × 103 dm3 mol−1 s−1 for Benzopurpurine.
Design of an Organic Ultramicroelectrode Array. Potential Use of Microstructures of Binary Langmuir–Blodgett Monolayers of Totally π-Conjugated Electroactive and Electroinactive Amphiphiles
Authors: Kunitake Masashi , Nasu Kenji , Narikiyo Yoshitaka , Manabe Osamu , Nakashima Naotoshi 
Published: July 2006

Abstract
Mixed monolayers of totally π-conjugated electroactive compounds, 1-methyl-4-[2-[4-[2-(4-quinolyl)vinyl]phenyl]vinyl]quinolinium perchlorate (1) and 1-methyl-4-[2-[4-[2-(4-pyridyl)vinyl]phenyl]vinyl]pyridinium perchlorate (2) and those of compound 1 and palmitic acid (PA) were formed on a 0.1 M KClO4 aqueous solution. Surface pressure area isotherms and fluorescence microscopic observations suggest that mixtures of compounds 1 and 2 form homogeneous mixed monolayers, but those of 1 and PA are phase-separated in the mixed monolayers. These monolayers were transferred to gold by using the Langmuir–Blodgett technique and then in situ electrochemical characterization was conducted. Cyclic voltammograms of the mixed monolayers of 1-2 and 1-PA on gold indicate rectified transmembrane electron transfer through the monolayer of 1 in the mixed monolayers to hexacyanoferrate(II) in solution. Potential-step chronocoulometric responses have revealed that the monolayer of 1 in the mixed LB monolayer of 1-2 acts as an organic ultramicroelectrode array electrode.
Crystalline-State Reaction of Cobaloxime Complexes. 18. Metastable Intermediate Structure Observed by a New X-Ray Diffractometer for Rapid Data Collection
Authors: Ohashi Yuji , Sakai Yoshii , Sekine Akiko , Arai Yoshifusa , Ohgo Yoshiaki , Kamiya Nobuo , Iwasaki Hitoshi 
Published: July 2006

Abstract
A crystal of [(R)-1,2-bis(methoxycarbonyl)ethyl]bis(dimethylglyoximato)(diphenylmethylphosphine)cobalt(III) changes its cell dimensions with retention of the single crystal form on exposure to visible light. The change is so fast that a new type of diffractometer (IPD-WAS) was developed for rapid data collection. The structures were analyzed at four different stages of the change using the diffractometer, which enabled us to collect the three-dimensional intensity data within 2 h. The cell dimensions of the monoclinic crystal varied from a = 13.678(2), b = 24.880(6), c = 9.391(2) Å, β = 107.99(1)°, and V = 3040(1) Å3 to a = 13.56(1), b = 25.06(1), c = 9.381(6) Å, β = 107.35(6)°, and V = 3044(3) Å3. The space group was changed from P21 to P21/n. The structures at four stages showed that there are two crystallographically independent molecules, A and B, in an asymmetric unit of the crystal before irradiation and that the chiral 1,2-bis(methoxycarbonyl)ethyl (bmce) group of the B molecule is completely inverted to the opposite configuration while the chiral bmce group of the A molecule remains unaltered after irradiation. This brings about an inversion center between the two molecules. The reaction cavity for the B bmce group is significantly greater than that for the A bmce group. At the intermediate stages, the B bmce group takes complicated disordered structures, which indicates that there exists a metastable intermediate structure in the inversion process.