bluuebunny/crossref_metadata_2025 huggingface dataset:
Latin America and the Cultural Consequences and Contradictions of Globalization
Authors: Oppenheim Lois Hecht
Published: December 2003

This paper examines the impact of the twin forces of neoliberalism and globalization on culture in Latin America. It argues that the application of a neo-liberal economic strategy over the past 25 years and the increased integration of the region's economy into the global economy have led to changes in cultural values and lifestyles. There is much evidence to support the idea that the changes denote the diffusion of a US-style market culture, which values individualism, competition, and consumerism. Chile was taken as a case study, as it has the longest and most successful experience with the neo-liberal model and globalization in the region. In Chile, and elsewhere, there are notable changes in political culture, including a less partisan and ideological electorate, increased political apathy, especially among the youth, and campaign formats that emphasize style over substance. At the same time, more complex cultural mixtures are also emerging, in which, for example, new campaign techniques are used to reinforce traditional values. There is also increasing resistance to the application of neo-liberal economic policies and to globalization in the region, although it is unclear to what extent this opposition can stem the international tide.
September 11: Early Thoughts on the Imbrication of Security, ICT, and International Relations
Authors: Tansu Okan
Published: December 2003

This paper provides more questions than answers and, for that matter, more questions than data. It is the hope of the author that this paper and other recent ones on the overlap of international relations, security, and informatics will stimulate other research that generates empirical data and thereby answer some of the important questions posed.
Situating Technology: Confrontations over the Use of Sonar among Turkish Fishermen and Marine Scientists
Authors: Knudsen Ståle
Published: December 2003

Since its introduction in the Turkish fisheries in 1980, use of the fish finder device sonar has been a controversial issue among fishermen and between fishermen and scientists. Most fishermen claim that sonars scare away or kill fish while local marine scientists contend that sonars have no such effect. What can study of this conflict tell us about the use of advanced technology in regions of the world far away from the metropolitan production of such technologies? In this ethnographic approach to a study in the field of Science and Technology Studies (STS) the fishermen's use of and the scientists' research on the sonar are surveyed. The article discusses the degree to which the adoption of sonar in the Turkish fisheries has resulted in a standardization of fishing practices—not only technologically, but possibly also in the way the fishermen perceive the hunt. Some theoretical arguments on how people relate to technology are reviewed and a phenomenologically inspired perspective advanced. It is argued that too much attention on finding the "Truth"—in this case whether the sonar is harmful to fish or not—diverts attention from more fundamental issues, such as what kinds of change sonar has brought to the social relations of production.
A novel form of mastocytosis associated with a transmembrane c-kit mutation and response to imatinib
Authors: Akin Cem , Fumo Gerard , Yavuz Akif S. , Lipsky Peter E. , Neckers Len , Metcalfe Dean D.
Published: December 2003

Mutational analysis of the c-kit gene in a patient with a previously undescribed variant of mast cell disease revealed a germline mutation, Phe522Cys, within the transmembrane portion of the Kit receptor protein. Transfection experiments revealed that the mutation caused ligand-independent autophosphorylation of Kit, which was inhibited by the tyrosine kinase inhibitor imatinib mesylate. The patient's bone marrow biopsy and aspirate displayed unique pathologic features with the presence of excessive numbers of mature-appearing mast cells and absence of aberrant mast cell surface expression of CD2, CD25, and CD35. Therapy with imatinib mesylate resulted in a dramatic improvement in mast cell burden and clinical symptoms. These results highlight the significance of the transmembrane region of Kit in activation of the molecule and its importance in mast cell development and suggest a role for screening for transmembrane c-kit mutations in patients with mastocytosis in association with the decision to use imatinib mesylate. (Blood. 2004;103:3222-3225)
Design of Macrocyclic Ligands for the Selective Extraction of f-Group Elements
Authors: Thi Kim Dung Nguyen , Kunogi Kenji , Ludwig Rainer
Published: December 2003

The relationship between the molecular structure of [1.6]metacyclophanes (calix[6]arenes) and the extractability of trivalent lanthanides and americium was studied by solvent extraction from weekly acidic aqueous into chloroform solutions. The ligands differ in number and position of the ionophilic carboxymethoxy- and (diethylcarbamoyl)methoxy-groups, as well as in their hydrophobicity. The separation of Am(III) from Ln(III) is achieved due to cooperative binding of different ionophilic groups. The separation factor, DAm(III)/DNd(III), is 15 for an unsymmetrically substituted ligand (4) and 61 for an symmetric ligand (6) bearing the same ionophilic groups. Extraction constants were calculated for the ligands and compared with reference data.
How to Evaluate the Structure of a Tetranuclear Mn Cluster from Magnetic and EXAFS Data: Case of the S2-State Mn-Cluster in Photosystem II
Authors: Hasegawa Koji , Ono Taka-aki , Inoue Yorinao , Kusunoki Masami
Published: December 2003

A theoretical method to extract structural information on spin-exchange-coupled manganese tetramers from the EPR spectroscopy data is presented. This method has been applied to two EPR data, i.e. the ground-state spin (S = 1/2) and the first excitation energy (30—37 cm−1), for the S2-state Mn tetramer in the photosynthetic oxygen-evolving complex, which exhibits a “g = 2 multiline” EPR signal. Based on the EXAFS data and the manganese chemistry, a simplified model spin Hamiltonian to describe the S2-state Mn cluster will be presented, such that two spin-exchange interactions due to 2.7—2.8 Å and/or 3.2—3.5 Å Mn–Mn bonds can vary from weak to strong coupling, sensitively, depending upon the bridge structure, except for a strong-antiferromagnetic interaction due to a 2.7 Å Mn(III)–Mn(IV) bond and the other weak ones. By computer-search of the possible spin-exchange structures with respect to these two parametric interactions, it was found that (1) a dimer of di-μ2-oxo bridged Mn dimers, a propeller-type tetramer in which the central Mn ion is chelated by three di-μ-oxo Mn cores and some other models are highly unlikely, (2) the most promising cluster is a trimer-plus-monomer type of distorted cubane, and (3) S* = 5/2 excited states are higher than the first excited state with S* = 3/2 (majority) or S* = 1/2 (minority).
Structural Characterization and Magnetic Properties of Triply Carboxylato-Bridged Dinuclear Copper(II) Complexes
Authors: Matsushima Hideaki , Koikawa Masayuki , Nukada Ryoji , Mikuriya Masahiro , Tokii Tadashi
Published: December 2003

A new series of carboxylato-bridged dinuclear copper(II) complexes ([Cu2(Ph2CHCOO)3(bpy)2]BF4 (1), [Cu2(Ph2CHCOO)3(bpy)2]CF3SO3 (2; blue form), [Cu2(Ph2CHCOO)3(bpy)2]CF3SO3 (3; green form), [Cu2(Ph2CHCOO)3(phen)2]BF4 (4), [Cu2{(ClPhO)2CHCOO}3(bpy)2]BF4 (5), and [Cu2{(ClPhO)2CHCOO}3(bpy)2]ClO4 (6), where Ph2CHCOO, (ClPhO)2CHCOO, bpy, and phen are diphenylacetate anion, bis(4-chlorophenoxy)acetate anion, 2,2′-bipyridine, and 1,10-phenanthroline, respectively) has been prepared. X-Ray crystallographic analyses reveal that complexes 1—6 have a triply carboxylato-bridged dicopper(II) core. Two copper(II) ions in 1 and 2are linked by one familiar “syn–syn bridging” carboxylate and two unique “monatomic bridging” carboxylates. In 3—6, two “syn–syn bridging” carboxylates and one “monatomic bridging” carboxylate connect two copper(II) ions. Complexes 2 and 3 are geometrically isometric with each other. Magnetic susceptibility data for the present complexes indicate that a weak antiferromagnetic interaction is operative in each dicopper core in 1, 2, 4, 5, and 6 with 2J values ranging from −5 to −13 cm−1, whereas a ferromagnetic coupling is operative in 3 with a 2J value of 9 cm−1.
Molecular Rearrangement Accompanied by Solid-State Isomerization of {N,N′-Di-3-ethoxysalicylidene-(R,S)(S,R)-1,2-diphenyl-1,2-ethanediamine}oxovanadium(IV)
Authors: Hoshina Gakuse , Ohba Shigeru , Nakajima Kiyohiko , Ishida Hiroyuki , Kojima Masaaki , Tsuchimoto Masanobu
Published: December 2003

Two geometrical isomers, exo- and endo-[VO(3-EtOsal-meso-stien)] (H2(3-EtOsal-meso-stien) = N,N′-di-3-ethoxysalicylidene-(R,S)(S,R)-1,2-diphenyl-1,2-ethanediamine), were selectively prepared separately. X-Ray structure analyses were carried out for two different crystals of the endo-isomer: endo-[VO(3-EtOsal-meso-stien)]·3H2O, (A), monoclinic P21/c, a = 10.435(3), b = 9.696(3), c = 30.948(3) Å, β = 94.87(2)°, V = 3120(1) Å3 and Z = 4; endo-[VO(3-EtOsal-meso-stien)]·CH3CN, (B), monoclinic P21/c, a = 15.935(3), b = 9.510(2), c = 20.891(2) Å, β = 100.58(1)°, V = 3112(1) Å3 and Z = 4. Under an argon atmosphere, the endo-isomer in both crystals A and B isomerized to the exo-isomer completely upon heating at 210 °C for 20 h. The X-ray powder diffraction patterns of the heated crystals A′ and B′ were approximately identical with that of exo-[VO(3-EtOsal-meso-stien)]·H2O (C). In the latter the V=O bonds are arranged in crystals to form a fairly weak linear chain structure (V=O···V=O···). The drastic rearrangement of the metal complexes in the solid state accompanied by the isomerization reaction indicates that the thermal reaction proceeds in a non-topochemical fashion.
The γ-Silicon Effect. II. The Substituent Effect on the Solvolysis of 3-(Aryldimethylsilyl)-2,2-dimethylpropyl p-Bromobenzenesulfonates
Authors: Nakashima Tohru , Fujiyama Ryoji , Fujio Mizue , Tsuno Yuho
Published: December 2003

Solvolysis rates of 3-(aryldimethylsilyl)-2,2-dimethylpropyl p-bromobenzenesulfonates were determined in 60% (v/v) aqueous ethanol (60E) and 97% (w/w) aqueous 2,2,2-trifluoroethanol (97Tw) at 50 °C. The effects of aryl substituents at the silyl atom on these solvolyses were correlated with unexalted σ° parameters, giving the ρ values of −0.87 in 60E and −1.08 in 97Tw. This indicates that there exists a certain extent of positive charge on the γ-silicon atom reflecting the delocalization of incipient carbocationic charge by participation of the Si–Cγ bond. The size of ρ values can be regarded as the effect of aryl ring on γ-Si via percaudal interaction in the rate-determining step.
Study of Reactive Intermediates in Photoinduced Electron Transfer Anti-Markovnikov Addition of Methanol to 1-Phenylcycloalkenes
Authors: Kojima Masanobu , Ishida Akito , Kuriyama Yasunao , Wada Yuji , Takeya Haruhiko
Published: December 2003

Irradiation of 1-phenylcycloalkenes (1) with cyanoaromatics as electron-accepting sensitizers in MeCN and PhH containing 1.0 M MeOH gave trans- (2) and cis-isomers (3) of anti-Markovnikov adducts. It was found that the isomer ratio of 2/3 depended on the ring size of 1 and solvent polarity, but not on the sensitizers used. The mechanisms for adduct formation in MeCN and PhH were studied by means of fluorescence spectroscopy, pulse radiolysis, and semiempirical molecular orbital calculation (PM3) and are discussed on the basis of the reactivities of the three kinds of intermediates involved in the reaction [cation radicals of 1 (1•+), free radicals generated by addition of MeOH to 1•+, and carbanions produced by reduction of the free radicals by anion radicals of the sensitizers]. On the basis of the results obtained by the calculation, it is concluded that the ratio of 2/3 in MeCN is dependent on the structures and stabilities of the radicals and carbanions, while for PhH the formation of exciplex between 1 and the sensitizers causes cis addition of MeOH to 1 due to steric hindrance, finally to yield 2 as the predominant adduct.
Stereochemical Behaviors of Cyclohexyl α-Sulfonyl Carbanions
Authors: Tanikaga Rikuhei , Nishikawa Takeshi , Tomita Naoki
Published: December 2003

Diastereoisomeric 4-(t-butyl)-1-(phenylsulfonyl)cyclohexanes 3 and 4-(t-butyl)-2-phenylsulfonyl-1-cyclohexanols 10 were subjected to H–D exchange, methylation, and allylation. The anions generated from 3 and 10 rapidly isomerized to those having a sulfonyl group in an equatorial position to form both equatorial and axial carbanions, in which a slight difference was found toward the subsequent electrophilic attack. The reaction of the dianion of 10 was little affected by an adjacent oxyanion and its countercation. The steric requirement of a bulky aggregate containing a sulfonyl group and a THF-solvated metal counterion may play an important role in the stereochemical behavior of α-sulfonyl carbanions.
Preparation of Cyclic Carbonates from Alkadienols, CO2, and Aryl or Vinylic Halides Catalyzed by a Palladium Complex
Authors: Uemura Kumiko , Shiraishi Daiziro , Noziri Masayoshi , Inoue Yoshio
Published: December 2003

A novel three-component reaction of alkadienol, CO2, and aryl or vinylic halide gives a vinyl group-substituted cyclic carbonate in one pot in the presence of a catalytic amount of a palladium complex. 2,3-Alkadienol affords five-membered ring carbonate in good yield, while 3,4-alkadienol effects the six-membered one successfully. 2,4-Alkadienol also takes part in this reaction to provide five-membered ring carbonate. A reaction pathway involving a π-allylic palladium species as an intermediate has been presumed.
Synthesis of 1-Amino-2-naphthalenecarboxylic Acid Derivatives via the Intramolecular Cyclization of 4-(2-Cyanophenyl)-2-butenoic Acid Derivatives and Its Application to the One-Pot Preparation of Benzo[h]quinazoline-2,4(1H,3H)-diones
Authors: Kobayashi Kazuhiro , Tanaka Hiroto , Takabatake Harumi , Kitamura Tomohide , Nakahashi Ryoji , Morikawa Osamu , Konishi Hisatoshi
Published: December 2003

The reaction of 2-(lithiomethyl)benzonitrile with 2-phenylthio-2-alkenoic acid derivatives in diglyme at −78 °C, followed by oxidation with sodium metaperiodate in aqueous MeOH at room temperature and the subsequent elimination reaction in refluxing toluene, gave 4-(2-cyanophenyl)-2-butenoic acid derivatives in moderate-to-fair overall yields. Intramolecular cyclization of these products using NaH in DMF at 0 °C gave 1-amino-2-naphthalenecarboxylic acid derivatives almost quantitatively. Successive treatments with an isocyanate without isolation of the aminonaphthalenecarboxylates under reflux afforded benzo[h]quinazoline-2,4(1H,3H)-diones in moderate-to-good yields.
Synthesis of 2,8-Dioxaspiro[4.5]decane-1,3,7,9-tetrone and the Reactions with Amines
Authors: Kato Jun , Seo Atsushi , Kiso Kazuki , Kudo Kazuaki , Shiraishi Shinsaku
Published: December 2003

For the studies of highly-sophisticated utilization of itaconic anhydride, some compounds of polybasic carboxylic acids having a quaternary or a spiro carbon atom were prepared, starting from itaconic anhydride and isoprene. Aliphatic tetracarboxylic dianhydride having a spiro carbon atom with five- and six-membered rings, 2,8-dioxaspiro[4.5]decane-1,3,7,9-tetrone (TCDA), was also obtained. The reaction of TCDA with primary amines and subsequent dehydration gave two types of products, either diimides or imide (with five-membered ring)-anhydrides (with six-membered ring), depending on the hydrocarbon moiety of the amines used. It was suggested that each imide-anhydride was formed by the intramolecular ring transformation of the intermediate amic acid-anhydride.
Thermodynamic Stabilities and Resonance Demand of Aromatic Radical Anions in the Gas Phase
Authors: Huh Chul , Kang Chul Hyun , Lee Hai Whang , Nakamura Hirotaka , Mishima Masaaki , Tsuno Yuho , Yamataka Hiroshi
Published: December 2003

The electron affinities (EAs) for a series of methyl benzoates, acetophenones, benzaldehydes, and benzophenones were determined by measuring the electron-transfer equilibria in the gas phase. The effect of substituents (X) in the benzene ring on the EAs of this series as well as the nitrobenzene and benzonitrile series were correlated in terms of the Yukawa–Tsuno equation,

It has been shown that the r− value, representing the degree of π-delocalization of the negative charge into the substituent (X) at position 4, increases linearly with decreasing EA of the unsubstituted member (X = H) of the respective series, i.e., 0.65 for nitrobenzene vs. 1.05 for benzaldehyde and 1.30 for benzonitrile. This tendency of the r− value leads to the conclusion that the negative charge of a less-stable radical anion is more significantly distributed in the benzene ring than in a stable radical anion, like that of nitrobenzene. Ab initio MO calculations show that when the EA of a Y-substituted benzene decreases, the total negative charge on the substituent (Y) in the radical anion also decreases, and that the bond lengths (C2C3/C5C6) shorten. These features are consistent with the conclusion derived from the experimentally obtained r− value.
A Practical Synthesis of (1S,2R)-1-Amino-2-indanol, a Key Component of an HIV Protease Inhibitor, Indinavir
Authors: Kajiro Hiroshi , Mitamura Shuichi , Mori Atsunori , Hiyama Tamejiro
Published: December 2003

A synthesis of (1S,2R)-1-amino-2-indanol (1), a key component of an HIV protease inhibitor, was accomplished through (R)-2-hydroxy-1-indanone ((R)-3), which was prepared by an intramolecular Friedel–Crafts acylation of (R)-2-acetoxy-3-phenylpropanoic acid readily available from d-(R)-phenylalanine. Alternatively, (R)-3 was obtained by an enzymatic resolution of (±)-2-acetoxy-1-indanone. Ketone (R)-3 was converted into 1 through an oxime formation and diastereoselective hydrogenation.
Photochemical Reactions of 1,2-Dicyanonaphthalene with Alkenes and Dienes
Authors: Kubo Yasuo , Kiuchi Kazuyuki , Inamura Isamu
Published: December 2003

The photoreaction of 1,2-dicyanonaphthalene (7) with 2-methyl-1-propene (2) in acetonitrile gave a [3 + 2]adduct at the 1,8-position of the naphthalene ring of 7 with loss of hydrogen cyanide, a [2 + 2 + 2]adduct consisting of 7, 2 and acetonitrile, and a cyclobutene-fused derivative, while that in benzene afforded a [3 + 2]adduct without loss of hydrogen cyanide and the cyclobutene-fused derivative. Yields of the products largely depended on the composition of the acetonitrile–benzene mixed solvent. The results suggested a polar nature of the [2 + 2 + 2]addition and a less polar nature of the formation of the cyclobutene-fused derivative. A maximal total yield (32%) of the [3 + 2]adducts was obtained in solvents containing 20—30 volume percent of acetonitrile. [3 + 2]Photocycloadditions at the 1,8-position of the naphthalene ring of 7 were found to be general in the reactions with cyclopentene, styrene, 1,3-butadiene, and isoprene. No photoreactions with 1-hexene were observed, possibly due to the poor electron-donating ability of 1-hexene. The generality of the [3 + 2]photocycloaddition was discussed in terms of the free energy change associated with single-electron transfer from alkenes or dienes to the singlet excited state of 7.
A Chiral Bimetallic Lewis Acid as a Reaction Template. Asymmetric Reduction of Unsymmetric Ketones with LiBH4
Authors: Nozaki Kyoko , Kobori Kayo , Uemura Toshitsugi , Tsutsumi Takaharu , Takaya Hidemasa , Hiyama Tamejiro
Published: December 2003

A new series of chiral bimetallic Lewis acids, 5,5′-bis[(R)-2-aryl-1,3,2-dioxaborolan-4-one], have been prepared from l-(+)-tartaric acid and arylboronic acids. In the presence of these Lewis acids, unsymmetric ketones were reduced quantitatively by LiBH4, in moderate to good ee’s (up to 99% ee). The counter cation of BH4− significantly affects the ee’s of the products. The reaction is applicable to aryl alkyl ketones, dialkyl ketones, and diaryl ketones.
Silyl-Substituted Dilithium Salt of Fulvene Dianion with 6 Center/8 Electron π-System: Synthesis and Characterization
Authors: Matsuo Tsukasa , Sekiguchi Akira , Sakurai Hideki
Published: December 2003

Treatment of fulvene derivatives bridged by Me2Si–X–SiMe2 chains (2a : X = CH2, 2b : X = O) with lithium metal in THF yields yellow crystals of the dilithium salt of fulvene dianion (3a and 3b) with 6 center/8 electron π-system. The molecular structure of the dianion dilithium 3a has been established by X-ray crystallography. The dianion dilithium 3a has a monomeric structure and forms a contact ion pair (bis-CIP) in the crystal. One of the lithium atoms is located above the center of the five-membered ring by η5-coordination, whereas the other one is bonded to the exo-cyclic carbon atom by η2-coordination. The structural parameters of 3a are discussed in comparison to those of the neutral starting molecule 2a. The structure of 3a in solution has also been discussed on the basis of NMR spectroscopic data. The two lithium ions of 3a are not fixed to the π-skeleton in toluene-d8, but are fluxional, giving a highly symmetrical bis-CIP structure. The spectral data in THF-d8 at 298 K also suggest the bis-CIP structure of 3a. However, the lithium ion on the five-membered ring is dissociated to yield an ion pair (CIP-SSIP) at low temperature in THF-d8, and two dianion species (bis-CIP and CIP-SSIP) were found in THF-d8.
Reversible Stretching of a Polymer-Supported Cobalt-Chelate Film in Response to Oxygen
Authors: Nishide Hiroyuki , Mizuma Hiroyuki , Tsuchida Eishun , McBreen James
Published: December 2003

The polymer-supported N,N′-di(salicylidene)ethylenediaminatocobalt(II) [Co(salen)] took up oxygen through 2/1 Co/dioxygen adduct formation. The composite film of the polymer-supported [Co(salen)] and polymer layers reversibly bent under an oxygen and nitrogen atmosphere. The stretching was caused by a structural change in the [Co(salen)] crystal before and after the oxygen-binding, which was analyzed based on the near-IR spectral and density change as well as EXAFS.
Salt Effects on Fluorescence Spectral Shifts of DNA-Bound Hoechst 33258 and Reaction Volumes of the Minor Groove Binding
Authors: Tang Guo-Qing , Tanaka Naoki , Kunugi Shigeru
Published: December 2003

In this study, salt effects on the interaction of Hoechst 33258 (2′-(4-hydroxyphenyl)-5-(4-methyl-1-piperazinyl)-2,5′-bi-1H-benzimidazole trihydrochloride) with several synthetic polynucleotide duplexes were studied by fluorescence spectral shifts and reaction volumes derived from the pressure dependence of binding equilibria. Both the excitation and emission spectra of Hoechst 33258 saturated by polyd(A)·polyd(T) or poly[d(A-T)]·poly[d(A-T)] shifted to shorter wavelengths as NaCl concentrations increased. The peak intensities first increased ([NaCl] < 100 mM) then started to decrease ( > 100 mM NaCl). Salt dependent blue shifts were also observed in their absorption spectra. These results were in contrast to what occurred to the drug complexed with poly[d(G-C)]·poly[d(G-C)] or poly[d(A-G)]·poly[d(C-T)]. The pressure dependence of the association equilibrium constants (Kp) of the drug and two A·T polymers was examined at several salt concentrations; the results helped to derive reaction volumes. In the case of the A-T copolymer, negative volume changes were found at all ionic concentrations studied. In contrast, in the case of the homopolymer, negative volume changes were found at lower salt concentrations (10 and 50 mM) while positive ones were found at higher concentrations (100 and 200 mM NaCl). These results are discussed in terms of the local structural deformation and hydration rearrangement of DNA.
Radiation-Induced Coloration of Photochromic Dithienylethene Derivatives
Authors: Irie Setsuko , Yamaguchi Tadatsugu , Nakazumi Hiroyuki , Kobatake Seiya , Irie Masahiro
Published: December 2003

The radiation sensitivity of photochromic 1,2-dithienylethenes was studied with the aim to develop a new reusable color dosimeter. Upon γ-irradiation, crystalline colorless 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene turned red, and the absorption intensity increased linearly with the absorbed dose. The red color was bleached by visible-light irradiation and the crystal could be reused. On the other hand, crystalline 1,2-bis(2-methyl-1-benzothiophen-3-yl)perfluorocyclopentene did not show any radiation-induced coloration. The radiation sensitivity in solution was also examined to understand the possible applications to solution and film color dosimeters. Although radiation-induced coloration of the above two compounds was observed in benzene, no color change was detected in hexane, 2-methyltetrahydrofuran and n-butyl chloride. Excitation energy migration and transfer mechanism is considered to play a role in the coloration process in benzene.
Photodimerization of 1-Alkylthymines Crystallized from Acetonitrile Solution
Authors: Tohnai Norimitsu , Inaki Yoshiaki , Miyata Mikiji , Yasui Nobuyoshi , Mochizuki Eiko , Kai Yasushi
Published: December 2003

Crystallization of 1-octylthymine from acetonitrile solution gave needles and plates. The needles gave the photodimer by irradiation of UV light, but the plates did not give the photodimer. Crystal structures of needles and plates were determined by X-ray analysis. There were two pairs of thymine, which gave the photodimers in the needles of 1-octylthymine. The isomer ratio of the photodimers indicated that thymine rotated disrotatory during the photodimerization reaction to give trans-anti, cis-anti, and trans-syn isomers. The crystal structure of the plates from acetonitrile solution was identical to the structure of plates obtained from ethanol solution, which was inactive for the photodimerization as reported in the previous paper. When the alkyl group became long, the formation of trans-syn photodimer decreased because strong interaction with the alkyl group inhibited moving of molecules. The photodimerization of 1-alkylthymine was concluded to occur when the rotation of the thymine is possible in the crystal.
Synthesis of Ru- and Os-Complexes of π-Conjugated Oligomers of 2,2′-Bipyridine and 5,5′-Bipyrimidine. Optical Properties and Catalytic Activity for Photoevolution of H2 from Aqueous Media
Authors: Hayashida Naoki , Yamamoto Takakazu
Published: December 2003

Oligomers of 2,2′-bipyridine (Oligo-bpy) and 5,5′-bipyrimidine (Oligo-bpym) with a linear structure have been prepared by an organometallic C–C coupling reaction. The oligomeric chelating ligands have a molecular weight of about 1500 corresponding to about 10 chelating bpy or bpym units, and form soluble complexes with [M(bpy)2]2+ (M = Ru or Os). The UV-vis absorption spectra of the metal complexes of Oligo-bpy exhibit a π–π* transition band at 355 ± 6 nm and a peak at 453 ± 18 nm assigned to a MLCT absorption. The UV-vis spectra of the metal complexes of Oligo-bpym also show an absorption peak attributed to the MLCT band. The water-soluble Ru complex of Oligo-bpy catalyzes visible-light-induced H2 evolution from aqueous media in the presence of Pt cocatalyst and triethylamine.
Conversion of Ag0 into Ag2+ in γ-Irradiated Organic Solid Solutions at 77 K as Studied by ESR
Authors: Matsuura Kaoru , Hase Hirotomo , Arai Shigeyoshi , Miyatake Yoko , Hoshino Mikio
Published: December 2003

Ethanol and 2-methyltetrahydrofuran (MTHF) solutions of silver perchlorate were irradiated with γ-rays at 77 K. Two kinds of silver atoms (Ag0) and a small amount of dimer cations (Ag2+) were formed in both solids immediately after irradiation. On storing at 77 K, both Ag0 species reacted with Ag+ to form Ag2+ in ethanol, while in MTHF only the minor Ag0 species reacted, resulting in less growth of Ag2+ yield than in ethanol. The mechanism for the formation of Ag2+ has been discussed in terms of thermal diffusion and quantum tunneling.
Crystalline-State Racemization of Cobaloxime Complexes. 21. Racemization of a Bulky (R)-1,2-Bis(ethoxycarbonyl)ethyl Group
Authors: Sato Hiroyuki , Ohashi Yuji
Published: December 2003

Three cobaloxime complexes with a chiral 1,2-bis(ethoxycarbonyl)ethyl group bonded to the cobalt atom: [(R)-1,2-bis(ethoxycarbonyl)ethyl]bis(dimethylglyoximato-N,N′)[(S)-1-phenylethylamine]cobalt(III), 1, [(R)-1,2-bis(ethoxycarbonyl)ethyl]bis(dimethylglyoximato-N,N′)(pyridine)cobalt(III), 2, and [(R)-1,2-bis(ethoxycarbonyl)ethyl]bis(dimethylglyoximato-N,N′)(propylamine)cobalt(III), 3, were analyzed by X-rays. The cell dimensions of 2 were remarkably changed when the crystal was irradiated with a xenon lamp. The structure after the irradiation indicated that the chiral 1,2-bis(ethoxycarbonyl)ethyl group was changed to the disordered racemates retaining the single crystal form. The other two crystals showed no change after the irradiation in the same conditions. Comparing the reaction cavities among four crystals analyzed so far, the shape rather than size of the cavity may play an important role in the crystalline-state racemization.
Fluctuations in Multicomponent Solutions and Light Scattering Intensity Revisited
Authors: Oshiman Hiroto , Momose Takamasa , Shida Tadamasa
Published: December 2003

The fluctuation of physical quantities in multicomponent solutions and its relevance to the light scattering intensity are reexamined. The fluctuation of thermodynamic quantities in solutions is derived without any constraint to the system, such as the assumption of constant volume or constant mass. Based on the mean square correlation among the fluctuation of thermodynamic variables, a general expression for the light scattering intensity is obtained. The present result coincides with that derived by assuming artificial constraints to the volume or the mass of the solutions, the procedure which has been adopted customarily by previous workers. The relation between the fluctuation of density and the mass fraction is also discussed.
Three Distinct Solvated Structures of p-Nitroaniline in Acetonitrile/CCl4 Mixed Solvents: A Combined Singular Value Decomposition Analysis of Ultraviolet Absorption and Raman Spectra
Authors: Mohanalingam Kathaperumal , Yokoyama Daisuke , Kato Chihiro , Hamaguchi Hiro-o
Published: December 2003

Ultraviolet absorption and Raman spectra of p-nitroaniline (pNA) have been measured in acetonitrile/CCl4 mixed solvents for seventeen different fractions of acetonitrile. The observed spectral changes were interpreted with the use of a combined singular value decomposition (SVD) analysis, in which the ultraviolet absorption and Raman spectra were combined into one set of spectra. A least-squares fitting analysis was carried out for the SVD decomposed spectra and their amplitudes, using a model in which three distinct species of pNA, the 1 : 0, 1 : 1, and 1 : 2 species, exist in equilibrium. Here, the 1 : 0, 1 : 1, and 1 : 2 species have 0, 1, and 2 acetonitrile molecules associated with pNA. Three intrinsic ultraviolet absorption and Raman spectra have been obtained as a result of the fitting analyses. The three intrinsic spectra show different degrees of charge transfer in the three different solvated forms of pNA. Two equilibrium constants, K1 for the equilibrium between the 1 : 0 and 1 : 1 species and K2 for 1 : 1 and 1 : 2, have been determined. These equilibrium constants give the standard free energy changes for the association of acetonitrile with pNA. A microscopic and quantitative view on the solvation of pNA in acetonitrile/CCl4 mixed solvents has thus been established.
Study of Electrode Kinetics of Zn2+–l-Amino Acids–γ-Picoline Mixed System
Authors: Vajhallya Seema , Khan Farid
Published: December 2003

Polarography was used to determine the stability constants (log β) of ternary complexes of Zn2+ with l-lysine, l-ornithine, l-threonine, l-serine, l-phenylglycine, l-phenylalanine, l-glutamic acid, and l-aspartic acid as primary ligands and γ-picoline as secondary ligand at pH = 8.50 ± 0.01 and ionic strength μ = 1.0 mol dm−3 NaClO4 at 25 °C. The waves of Zn and its complexes were quasireversible. Zn formed 1 : 1 : 1, 1 : 1 : 2, and 1 : 2 : 1 complexes. The kinetic parameters viz. the standard rate constant (k), degree of irreversibility (λ), and charge transfer coefficient (α) were also determined. The trend of the stability constants of Zn2+complexes with these amino acids and γ-picoline is l-lysine < l-ornithine < l-threonine < l-serine < l-phenylglycine < l-phenylalanine < l-glutamic acid < l-aspartic acid, which is explained on the basis of the sizes and basicities of the primary ligands.
Determination of Basicity of Core X and Terminal Y Ligands (X, Y = S and Se) of Reduced, Oxidized, and Super-Oxidized Forms of [Fe4X4(YAd)4]2− (Ad = 1-Adamantyl) in Aqueous Solutions
Authors: Nakamoto Masami , Fukaishi Kenji , Tagata Tsuyoshi , Kambayashi Hide , Tanaka Koji
Published: December 2003

A series of [Fe4X4(YAd)4]2− (X, Y = S, Se; Ad = 1-adamantyl) were prepared as a model of high potential iron–sulfur proteins. Hydrolysis of the clusters was effectively depressed in aqueous poly[2-(dimethylamino)hexanamide] (PDAH) solutions due to the enbedding effect in hydrophobic environment and/or inhibition of dissociation of the terminal ligand into the aqueous media. Cyclic voltammetry of those clusters in aqueous PDAH solutions showed pH-dependent redox potentials of not only the [Fe4X4]+/2+ but also the [Fe4X4]2+/3+ (X = S and Se) couples, resulting from redox-linked protonation reactions of three oxidation states of [Fe4X4(YAd)4]n− (n = 1—3). pKavalues of the reduced, oxidized, and super-oxidized forms of [Fe4X4(YAd)4]2− were determined by computer simulation of the pH dependent redox potentials. The basicity of the core X (X = S and Se) of three oxidation states of [Fe4X4(YAd)4]n− (n = 1, 2, 3) was stronger than the terminal YAd (Y = S and Se) ligands: in the case of the mono-protonated [Fe4X4(YAd)4]3−(H+) and [Fe4X4(YAd)4]2−(H+), basicity of the terminal YAd ligand of [Fe4X4(YAd)4]2−(H+) becomes stronger than that of core X, although the core X of [Fe4X4(YAd)4]3−(H+) still showed a stronger basicity than those of terminal YAd ligands.
Complex Formation and Redox Reactions in Copper–Pterin Cofactor Systems. Possible Relevance to Phenylalanine Hydroxylase
Authors: Funahashi Yasuhiro , Kato Chie , Yamauchi Osamu
Published: December 2003

With a view to understanding better the redox reactions between the metal center and the pterin cofactor in phenylalanine hydroxylase (PAH) and the effects of possible sulfur coordination to the metal center, we isolated model copper(II) complexes of 2,2′-bis(2-pyridylmethyl)amine (dpa), S-ethyl-N-(2-pyridylmethyl)aminoethanethiol (pat), and pterin-6-carboxylate (ptc), [Cu(dpa)(ptc)]·H2O·CH3OH (1), [Cu(pat)(Cl)]Cl·H2O (2), and [Cu(pat)(ptc)]·3H2O (3), of which 1 and 3 contained ptc as a cofactor model. These binary and ternary Cu(II) complexes were studied by X-ray diffraction, spectroscopic, and electrochemical methods. Redox reactions between Cu(II) complexes ([Cu(dpa)]2+ or 1) and tetrahydropterins (5,6,7,8-tetrahydro-6,7-dimethylpterin (h4dmp) or 5,6,7,8-tetrahydropterin-6-carboxylate (h4ptc)) were also investigated by time-resolved spectroscopic methods. The molecular structures of 1, 2, and 3 showed that dpa and pat occupy three equatorial positions and that ptc in 1 and 3 is vertically coordinated. Complexes 2 and 3 exhibited relatively high redox potentials due to thioether sulfur coordination (E1/2 = −0.06 and −0.18 V vs. Ag/AgCl, respectively) in contrast to [Cu(dpa)]2+ and 1 (E1/2 = −0.32 and −0.39 V, respectively). Coordination of h4dmp and h4ptc to the Cu(II) center of [Cu(dpa)]2+ and 2 to form ternary complexes was detected by the ESR spectra with the use of the rapid mix-freeze-quenching technique; subsequent redox reactions were concluded from the absorption spectral changes.
Selective N–N and W–N Bond Cleavage of Tungsten Pyrrolylimido Complexes Derived from Tungsten Dinitrogen Complex
Authors: Sasagawa Takao , Seino Hidetake , Ishii Youichi , Mizobe Yasushi , Hidai Masanobu
Published: December 2003

Treatment of the pyrrolylimido complexes cis,trans-( [WX2(NNCH=CHCH=CH)(L)(PMe2Ph)2] ) (X = Cl, Br, I; L = PMe2Ph (6), CNBut, CO, PhC≡CH, PhCHO, Br) with LiAlH4or KOH produced pyrrole, 1-aminopyrrole, and ammonia, where both the reaction conditions and the nature of the ligand L showed significant effects on the pyrrole/1-aminopyrrole selectivity. Thus, reduction of cis,trans-( [WBr2(NNCH=CHCH=CH)(CNBut)(PMe2Ph)2] ) with LiAlH4 followed by methanolysis gave pyrrole and ammonia in almost quantitative yields. On the other hand, 1-aminopyrrole was quantitatively produced from the complexes by the reaction of KOH in alcohol when L = CO, PhC≡CH, or PhCHO. While analogous treatment of 6 with KOH in ethanol afforded both pyrrole and 1-aminopyrrole with low selectivity under N2 atmosphere, 1-aminopyrrole was produced from 6 in excellent yield under 1 atm of CO. On the contrary, pyrrole and ammonia were selectively formed from the reaction of 6b (X = Br) with KOH/18-crown-6 ether in THF. Replacement of one of the PMe2Ph ligands in the diazoalkane complex cis,mer-[WBr2(NN=CMeCH2CH2COMe)(PMe2Ph)3] (12) by CO or CNBut facilitated the cyclization of the diazoalkane ligand to provide the (2,5-dimethylpyrrolyl)imido complexes cis,trans-( [WBr2(NNCMe=CHCH=CMe)(L)(PMe2Ph)2] ) (L = CO 14; L = CNBut  15), although complex 12 failed to undergo the ring closure by aqueous HBr. 2,5-Dimethylpyrrole and 1-amino-2,5-dimethylpyrrole were selectively obtained by LiAlH4 reduction of 15 and by treatment of 14 with KOH in EtOH, respectively.
Synthesis and Redox Properties of Amino Acid-Bridged Dinuclear Iron(III) Complexes
Authors: Umakoshi Keisuke , Tsuruma Yasuhiro , Oh Chang-Eon , Takasawa Akira , Yasukawa Hana , Sasaki Yoichi
Published: December 2003

A series of dinuclear iron(III) complexes with μ-O,O′-bridging amino acids (as zwitter ionic forms) have been prepared: [Fe2(μ-O)(μ-amino acid)(tpa)2](ClO4)4 (tpa = tris(2-pyridylmethyl)amine; amino acid = l-valine (1), l-proline (2), l-alanine (3), l-tyrosine (4), l-tryptophan (5), l-phenylalanine (6), l-alanyl-l-alanine (7)). Among them, 1, 2, and 7 were structurally characterized at 163 K. The non-equivalent ligating mode of the two tpa ligands is common to all the three complexes. The amino acid bridged complexes exhibit irreversible one electron reduction waves with splitting or accompanying shoulders. The bulk electrolysis of these complexes confirmed that the total number of electrons involved in the reduction is one; i.e. Fe2(III, III) → Fe2(II, III). Addition of acid or base leaves positive or negative components, respectively, of the splitting wave. This phenomenon was interpreted as a proton coupled electron transfer where the protonated and deprotonated amino acid bridged species are reduced at different potentials. Magnetic susceptibility measurements in the temperature range, 2—300 K, revealed antiferromagnetic coupling with J = −116, −129, −120, −120, and −129 cm−1 for 1, 2, 4, 6, and 7, respectively (H = −2JS1·S2; S1 = S2 = 5/2).
Syntheses and Magnetic Properties of 1,4,8,11-Tetraazacyclotetradecanenickel(II) Tetra-, Hexa-, and Octa-cyanometalates
Authors: Nowicka Beata , Hagiwara Masayuki , Wakatsuki Yasuo , Kisch Horst
Published: December 2003

A series of 1,4,8,11-tetraazacyclotetradecanenickel(II) cyanometalates ([Ni(cyclam)]3[Fe(CN)6]2·11H2O (1), [Ni(cyclam)]2[Mo(CN)8]·3H2O (2), [Ni(cyclam)]2[W(CN)8]·3H2O (3), and [Ni(cyclam)][Pt(CN)4]·3H2O (4) (cyclam = 1,4,8,11-tetraazacyclotetradecane)) was obtained and characterised. Magnetic-susceptibility measurements showed a high-spin configuration (S = 1) of Ni(II) in all compounds, which was attributed to the interaction of cyano ligands with free axial coordination sites on nickel. The presence of bridging cyano groups in 1 was confirmed by IR and visible reflectance spectra. Compound 1 shows a long-range magnetic order below 8 K.
Catalytic Esterification of Alcohols, Carboxylic Acids and Transesterification Reactions with Cerium(IV) Triflate
Authors: Iranpoor Nasser , Shekarriz Marzieh
Published: December 2003

Esterification reactions of alcohols with acetic, chloroacetic, trifluoroacetic, propionic, stearic, and benzoic acids were catalyzed with Ce(OTf)4 in a solvent or under solvent-free conditions with high yields. The formylation and acetylation of primary and secondary alcohols were also easily achieved in ethyl formate and ethyl acetate. A high retention of the configuration was observed in the acetylation and formylation of (−)-menthol.
Synthesis of Unsymmetrically Substituted Antimony(V) Tetraphenylporphyrins
Authors: Satoh Wataru , Masumoto Shuji , Shimizu Masakazu , Yamamoto Yohsuke , Akiba Kin-ya
Published: December 2003

The following nine unsymmetrically axially substituted antimony(V) tetraphenylporphyrins with an antimony–carbon bond or an antimony–fluorine bond were synthesized: [(TPP)Sb(Me)(OEt)]+ClO4− (1-ClO4), [(TPP)Sb(Me)(OC6H4CH3-p)]+ClO4− (2-ClO4), [(TPP)Sb(Me)(SC6H4CH3-p)]+ClO4− (3-ClO4), [(TPP)Sb(Me)(NHC6H4CH3-p)]+ClO4− (4-ClO4), [(TPP)Sb(Me)(NHCH2C6H5)]+ClO4− (5-ClO4), [(TPP)Sb(Me)(OC(=O)C6H4Cl-m)]+PF6− (6-PF6), [(TPP)Sb(Me)(Et)]+PF6− (7-PF6), [(TPP)Sb(Me)(CH2CHMe2)]+PF6− (8-PF6), and [(TPP)Sb(F)(OH)]+ClO4− (9-ClO4). All nine compounds were stable towards atmospheric moisture. X-Ray crystallographic analysis of 6-PF6 revealed that the antimony atom lies at 0.182 Å out-of-plane of the four nitrogens (Δ4N) toward the carbon atom; 6-PF6: space group P21/n, a = 25.49(2), b = 11.27(1), c = 16.58(1) Å, β = 96.74(5)°, R = 0.064.
Reaction of N1,N2-Diarylacetamidines with Ethyl 2-Oxoindolin-3-ylidenecyanoacetate and Benzylidenemalononitriles
Authors: Gomaa Mohsen A-M , El-Din Ahmed M Nour , Mohamed Azza A
Published: December 2003

1′-Aryl-6′-arylimino-2,2′-dioxospiro[(2,3-dihydro-1H-indole)-3,4′-perhydropyridine]-3′-carbonitriles 5a—d together with ethyl 2-amino-4-[1-aryl-2,6-bis(arylamino)-4-hydroxy-1,4-dihydro-4-pyridyl]quinoline-3-carboxylate 9a—c were obtained from the reaction of N1,N2-diarylacetamidines 1a—d with ethyl 2-oxoindoline-3-ylidenecyanoacetate 3. Acetamidines 1a—c also reacted with the benzylidenemalononitriles 10a—d to afford the adducts 1,4,5,6-tetrahydropyridines 13a—f.
Kinetic and Mechanistic Investigation of a Hydrolytic Catalytic Antibody Having Remarkable Substrate Specificity: Substituent Effects on Catalysis
Authors: Wada Yumiko , Yamamoto Masayoshi , Sudo Yukio , Ono Mitsunori
Published: December 2003

Monoclonal antibodies were raised against p-nitrophenyl phosphonate to elicit catalytic antibodies capable of hydrolyzing p-nitrophenyl carbonates. Of 34 clones selected, three clones catalyzed the hydrolysis of methyl p-nitrophenyl carbonate. Interestingly, 4A1, an antibody out of those clones, showed a significant rate acceleration against substrates that differ from the given haptenic structure in the carrier-proximal region. The rate acceleration (kcat/kuncat) for one of the specific substrates is 6.4 × 104, 20-fold higher than that of a substrate congruent with the hapten. Kinetic analysis of Km and kcat values, as well as the affinity constant (Kd) values of the corresponding transition-state analogs, indicated that the rate enhancement is associated with a decrease in the activation energy due to stabilization of the transition-state in the cleavage reaction. In addition, the inactivation of 4A1 catalytic antibody upon hydrolysis of a particular substrate was observed. The 600 MHz 13C NMR measurement clearly showed that the 13C-labeled fragment attached covalently to the 4A1 antibody, proving formation of an acyl-antibody. Further kinetic analysis study demonstrated that the 4A1 catalytic antibody uses a multistep kinetic sequence for the hydrolytic reaction.
Organic Photoelectrochemical Cell Mimicking Photoinduced Multistep Electron Transfer in Photosynthesis: Interfacial Structure and Photoelectrochemical Properties of Self-Assembled Monolayers of Porphyrin-Linked Fullerenes on Gold Electrodes
Authors: Imahori Hiroshi , Ozawa Shinichiro , Ushida Kiminori , Takahashi Masao , Azuma Takayuki , Ajavakom Anawat , Akiyama Tsuyoshi , Hasegawa Masato , Taniguchi Seiji , Okada Tadashi , Sakata Yoshiteru
Published: December 2003

Self-assembled monolayers (SAMs) technique has been applied to porphyrin-linked fullerene systems to mimic supramolecular photoinduced charge-separation (CS) events in photosynthesis. Porphyrin-linked C60 molecules with a sulfide group were designed to self-assemble on a gold surface using S–Au interaction. The structure of the SAMs formed on gold electrodes was investigated by spectroscopic methods including X-ray photoelectron spectroscopy (XPS), ultraviolet (UV)-visible spectroscopic ellipsometry, UV-visible absorption spectroscopy, and Fourier transform infrared (FTIR) spectroscopy as well as electrochemical studies. These results indicate that the SAMs have loosely packed structure; the porphyrin-C60 molecules are tilted and nearly parallel onto the gold surface. Short-circuit photocurrent with a level of sub-μA cm−2 was observed for the photoelectrochemical cell in the presence of methylviologen (MV) under illumination with ca. 4 mW cm−2. The maximum intensity of the photocurrent in free-base porphyrin-C60 system is five times larger than that in the corresponding free-base porphyrin system, indicating that C60 is an effective mediator in multistep electron transfer (ET) processes. A possible mechanism for the photocurrent generation is discussed in terms of the photodynamics of porphyrin-linked fullerenes in solution.
Donor–Acceptor Binary Photocatalysis System Illustrated by the Intramolecular Cyclization of a Cyclopropanone Acetal Tethered to Cyclohexen-2-one
Authors: Oku Akira , Miki Toshiyuki , Abe Manabu , Ohira Masatoshi , Kamada Tohru
Published: December 2003

Irradiation of 2-[3-(2-methoxy-1-phenyl-2-TBDMSO-cyclopropyl)-propyl]-2-cyclohexen-1-one (5) in the presence of Mg(ClO4)2 (1 mol equiv) and 9,10-dicyanoanthracene (DCA, 0.5 mol equiv) in acetonitrile formed methyl 5-oxo-1-phenyldecahydro-1-naphthaleneacetate (6) in 63% yield. When pyrene was adopted in place of DCA, the yield of 6 was 38%. The results indicate that the photocyclization of 5 induced by the SET can be catalyzed by both donor- and acceptor-type photocatalysts. Irradiation of a similar substrate, 4-(2-methoxy-1-phenyl-2-TBDMSO-cyclopropyl)butyl 2-naphthyl ketone (21), produced methyl 2-hydroxy-2-(2-naphthyl)-1-phenylcyclohexaneacetate (27) in 13% in the presense of p-dicyanobenzene (0.1 mol equiv) and 8% in its absence.
Allenyl(vinyl)methane Photochemistry. Photochemistry of Methyl 4,4-Dimethyl-2,5,6-heptatrienoate Derivatives
Authors: Tsuno Takashi , Sugiyama Kunio
Published: December 2003

Both the direct and sensitized photolyses of [2-(1,2-propadienyl)-substituted alkylidene]malonates gave mainly intramolecular [2+2] cycloadducts. On the other hand, the direct irradiation of methyl (E)-4,4-dimethyl-2,5,6-heptatrienoate (3a) competitively underwent E–Z geometric isomerization and intramolecular [2+2] cycloaddition, though prolonged irradiation led to [2+2] cycloadducts as main products. For methyl (E)-4,4,7-trimethyl-2,5,6-octatrienoate (3b), the intramolecular [2+2] cycloaddition occurred under both direct and sensitized irradiation and the E–Z geometric isomerization scarcely occurred. In these allenyl(vinyl)methanes under direct irradiation, the 1,2-propadienyl-substituted esters gave a 1,2-propadienylcyclopropane or (2-ethenylidenecyclopropyl)acetate as a minor product. When 3b was irradiated in the presence of hydrogen selenide in toluene, cyclopentenes were formed. The formation of the cyclopentenes indicated that the biradical intermediate is a cyclopentane-1,3-diyl radical. By MO calculations of the model compounds for the chromophores of the esters, it is suggested that the preferential initial bond for the 1,2-butadienyl- or 3-methyl-1,2-butadienyl-substituted esters is between the C6 (allene center carbon) and C2 (α-carbon), while 1,2-propadienyl-substituted esters can also be bonded between the C5 and C3 (β-carbon).