bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface Imprinting. Characterization of a Latex Resin and the Origin of the Imprinting Effect
Authors: Tsukagoshi Kazuhiko , Yu Kai Yu , Maeda Mizuo , Takagi Makoto , Miyajima Tohru 
Published: July 2006

Abstract
In accordance with the concept of Surface Imprinting, as proposed by the present authors, a Cu(II)-imprinted microsphere was studied in detail in order to obtain information about the origin of the imprinting effect. Unimprinted and Cu(II)-imprinted microspheres were prepared under several pH (4.0, 5.0, 5.6, or 6.0) conditions in second-step polymerization. The obtained microspheres were characterized regarding particle form, size-distribution pattern, average diameter, Cu(II) adsorption behavior, and so on. During preparation at pH 4.0—5.6 in the second-step polymerization, imprinted microspheres adsorbed Cu(II) more effectively than did unimprinted microspheres in this pH range, indicating a clear metal-imprinting effect. On the other hand, the imprinting effect was not observed during preparation at pH 6.0, because of the formation of copper(II) hydroxide precipitates. The maximum imprinting effect was provided by microspheres obtained at pH 5.6. Spectroscopic studies were made on Cu(II)-loaded microspheres. The FT-IR spectra suggested that carboxyl groups on the microsphere surface participated in the Cu(II) binding in their ionized carboxylate forms. An FE-SEM (ångstrom SEM) observation of the microsphere indicated a smooth surface structure at the 10 nm level. The collected data indicate that the origin of the imprinting effect on a Cu(II)-imprinted microsphere is the interaction between Cu(II) and the carboxylate group at the aqueous-organic interface, supporting the concept of Surface Imprinting.
Synthesis and Evaluation of Novel Crowned Coumarins as Self-Catalytic Fluorescence Reagents
Authors: Takadate Akira , Masuda Toshinobu , Murata Chiyomi , Tanaka Toshiharu , Goya Shujiro 
Published: July 2006

Abstract
Three coumarin reagents carrying crown-ether moieties as catalytic sites for the fluorescence derivatization of carboxylic acids were designed and synthesized. The catalytic abilities of these reagents were evaluated based on the stability constants (Ks) for complexation with metal acetates in methanol. The derivatization reactions of carboxylic acids with these reagents proceeded self-catalytically without crown-ether catalysts, and gave the corresponding coumarin esters in good yields. It was found that their reactivities significantly depended upon the metal-binding ability of the reagent molecules from kinetic treatments of the reactions. The derivatized products showed remarkably high fluorescence quantum yields of above 0.8 in methanol. These results suggested that the functionalization of reagents was a quite useful approach for the development of new-type analytical reagents.
Asymmetric Synthesis of 4-Phenyl-1,5-diazacyclooctan-2-one Using Optically Active Vinyl Sulfoxides
Authors: Itoh Nobuhiro , Matsuyama Haruo , Yoshida Masato , Kamigata Nobumasa , Iyoda Masahiko 
Published: July 2006

Abstract
Both enantiomers of (S)- and (R)-4-phenyl-1,5-diazacyclooctan-2-ones (7) were synthesized stereoselectively with good optical purity by the asymmetric conjugate addition of pyrazolidine to optically active vinyl sulfoxides, t-butyl (E)-2-[(R)- and (S)-p-tolylsulfinyl]cinnamates, respectively. Starting from 7, a synthesis of optically active homaline was achieved.
The Cyanation of Vinyl Halides with Alkali Cyanides Catalyzed by Nickel(0)–Phosphine Complexes Generated In Situ: Synthetic and Stereochemical Aspects
Authors: Sakakibara Yasumasa , Enami Hiroji , Ogawa Hiroshi , Fujimoto Shinpei , Kato Hiroyuki , Kunitake Katsumi , Sasaki Ken , Sakai Mutsuji 
Published: July 2006

Abstract
The cyanation of β-bromostyrenes catalyzed by Ni(PPh3)n, which was generated in situ from NiBr2(PPh3)2–Zn–PPh3 (Ni : Zn : P = 1: 3 : 2 molar ratio), was at first examined with various MCN (M = K, Na)-dipolar aprotic solvent systems by several procedures. The presence of excess cyanide ion inhibited the reaction. However, when the KCN–DMF system with some intermediate cyanide solubility was used, the nitriles were obtained in high yields and high stereoselectivity at 50 °C by almost all of the procedures attempted. On the contrary, the KCN–HMPA and KCN–MeCN systems with low cyanide solubilities accelerated the coupling of the halides to inhibit the cyanation, and in general the NaCN–DMF and NaCN–HMPA systems with high cyanide solubilities needed to reduce Ni(II) before adding MCN in order to make the catalytic reaction start. Vinyl halides such as 1- and 2-halo (Cl, Br)-1-alkenes, 2-bromo-2-butenes, 3-bromo-3-hexenes, and 1-chlorocyclohexene were also cyanated using suitable procedures and MCN–solvent systems to give the corresponding nitriles in high yields and fair-to-good stereoselectivities. However, with (Z)-2-ethoxy-1-bromoethene the (E)-nitrile, though its selectivity markedly varied with the reaction temperature, was obtained as the main product. The cyanation of ethyl (Z)-β-bromoacrylate and ethyl α-bromoacrylate was unsuccessful due to polymerization.
Synthesis and Positive Cooperativity in Cation Binding of New Podand Possessing Tropolonoids at Both Terminals of Oligoethylene Glycol
Authors: Kato Tadahiro , Hiraide Akira , Suda Miki , Kanbe Takuro , Nozoe Tetsuo 
Published: July 2006

Abstract
The oligoethylene glycol derivatives having tropolonoid moieties at both terminals were synthesized. The diethylene to pentaethylene glycol derivatives formed Zn complex in an intramolecular fashion, which extracted metal picrates from the aqueous solution. The larger cooperativity was observed in the extractions of alkaline earth metal ions as compared with those of alkaline metal ions.
Syntheses of 2-[(1S,3S)-1-Amino-3-carboxy-3-hydroxypropyl]thiazole-4-carboxylic Acid and the Tripeptide Skeleton of Nosiheptide Containing the Acid
Authors: Shin Chung-gi , Nakamura Yutaka , Yamada Yasuhiro , Yonezawa Yasuchika , Umemura Kazuyuki , Yoshimura Juji 
Published: July 2006

Abstract
The stereoselective synthesis of an amino acid component called Fragment D, N,O-diprotected 2-[(1S,3S)-1-amino-3-carboxy-3-hydroxypropyl]thiazole-4-carboxylic acid of a macrobicyclic peptide antibiotic nosiheptide, was achieved by two routes. The dipeptide, Fragment B-C, 2-[(Z)-1-(N,O-isopropylidene-l-threonylamino)-1-propenyl]thiazole-4-carboxylic acid was also synthesized by the thiazole ring formation from (Z)-2-(N,O-diprotected l-threonylamino)-2-butenethioamide with ethyl bromopyruvate. The coupling of two components by using a condensing agent gave the expected tripeptide 2, which is an important partial skeleton of the nosiheptide.
A Tetrameric Enkephalin Analog for the Putative Multivalent Interaction with Opioid Receptors
Authors: Kondo Michio , Kitajima Hiroshi , Yasunaga Teruo , Kodama Hiroaki , Costa Tommaso , Shimohigashi Yasuyuki 
Published: July 2006

Abstract
Based on increased affinity and selectivity of dimeric enkephalin analogs for opioid receptors, divalent interactions have been demonstrated between opioid peptides and receptors. To explore the receptor multivalency suggested by fluorescent microscopic studies, a novel type of tetrameric enkephalin analog was designed and synthesized. The tetrameric enkephalin comprises four [d-Ala2, Leu5]enkephalin molecules coupled with the amino groups of the gem-diamino derivative of cystine, which was derived from cysteinamide by a Hofmann-type rearrangement, causing an amide-to-amine conversion. By the reduction of the gem-cystine disulfide bond in the tetramer, two dimeric analogs with a free or p-methoxybenzyl-protected mercapto group were also prepared. The receptor binding characteristics of these tetramer and dimers for the δ and μ receptors were analyzed in an NG108-15 cell and rat-brain membranes. The affinity of the tetrameric analog for the δ receptors was about equal to that of the dimers, but 2—4-fold lower for the μ receptors. The dimers were 5—8-fold δ-selective, and, thus, the tetramer exhibited a high selectivity for the δ receptors. A divalent interaction mechanism was considered between the tetrameric ligand and the δ opioid receptors.
Allenyl(vinyl)methane Photochemistry. Photochemistry of 5-[2-(1,2-Propadienyl)-Substituted Alkylidene]-2,2-dimethyl-1,3-dioxane-4,6-diones
Authors: Tsuno Takashi , Sugiyama Kunio 
Published: July 2006

Abstract
The Photochemistry of 5-[2-(1,2-propadienyl)-substituted alkylidene]-2,2-dimethyl-1,3-dioxane-4,6-diones has been studied. These acylals formed an intramolecular charge-transfer (CT) complex between the 1,2-propadienyl and vinyl moieties in acetonitrile and in hexane, the direct photolyses of which gave (1-alkenylidene)cyclopropanes as the main products, and the intramolecular [2+2] cycloadducts, 3-alkylidene-2′,2′,5,5-tetramethylspiro[bicyclo[2.1.0]pentane-2,5′-[1,3]dioxane]-4′,6′-diones as minor products. The (1-alkenylidene)cyclopropanes were produced from the enol intermediate via a preferred 1,5-hydrogen transfer of a diradical, which was formed via an intramolecular CT excited state. On the other hand, the acetone-sensitized photolyses afforded mainly the intramolecular [2+2] cycloadducts. It is considered that the lowest triplet energies of these acylals in acetonitrile were estimated to lie in the range of 250—290 kJ mol−1, and that these energies were near to the values of the reported triplet energies of α,β-unsaturated esters, because the allene underwent a [2+2] cycloaddition to the triplet vinyl moiety, excited by triplet sensitization.
Photolyses of Derivatives of Naphthyl and Anthryl Phosphates and Methylphosphonates
Authors: Nakamura Mitsunobu , Sawasaki Koichi , Okamoto Yoshiki , Takamuku Setsuo 
Published: July 2006

Abstract
Upon UV irradiation in acetonitrile, tri-1-naphthyl phosphate and di-1-naphthyl methylphosphonate underwent intramolecular rearrangement and ipso-coupling to give 1,2′-binaphthalen-1′-ol and 1,1′-binaphthalene, respectively. In the photolyses of tris(4-methoxy-1-naphthyl) phosphate and bis(4-methoxy-1-naphthyl) methylphosphonate in methanol, 4,4′-dimethoxy-1,1′ -binaphthalene, 1′,4,4′-trimethoxy-1,2′-binaphthalene, and 2,4,4′-trimethoxy-1,1′-binaphthalene were generated. Tri-9-anthryl phosphate and di-9-anthryl methylphosphonate underwent intramolecular (4+4) photocycloaddition between two anthryl groups. The fluorescence spectra of the naphthyl derivatives had two emission bands ascribed to an intramolecular excimer and a monomer, but the fluorescence spectra of the anthryl derivatives had only a monomer emission band. These photoluminescence behaviors are closely related to the reactivities of the compounds.
Substituent Effects on Chloride Transfer Equilibrium in the Gas Phase. Intrinsic Resonance Demand of Benzyl Cation
Authors: Mishima Masaaki , Arima Kiyoshi , Inoue Hiroki , Usui Satoshi , Fujio Mizue , Tsuno Yuho 
Published: July 2006

Abstract
Relative chloride ion affinities of 48 carbocations have been measured by the chloride ion transfer equilibrium of benzyl chlorides in the gas phase. The substituent effects on the chloride affinity of benzyl cation have been analyzed in terms of the LArSR Eq., giving a ρ = −14.0 and an r+ = 1.29. The r+ value higher than the corresponding value of unity for the α-cumyl(2-phenyl-2-propyl) cation clearly indicates that the benzyl cation has an enhanced resonance demand in the intrinsic carbocation stability compared with that of the α-cumyl one. Most importantly, the unique r+ value of 1.29 for the gas-phase benzyl cation stability has been found to be identical with the value observed for the kc ionization process of the solvolysis of the activating substituent range of benzyl tosylates. The identity of the r + value, which is consistent with previous observations for the relevant benzylic carbocation systems, suggests that the intramolecular charge-delocalization in the transition state of the kc solvolysis should be quite close to that of the carbocation intermediates. It is concluded that the exalted r+ value observed for the kc solvolysis of benzyl tosylates is not a correlational artifact arising as a result of the non-linearity caused by the kc–ks mechanistic transition but is due to the enhanced resonance stabilization of the benzyl cation compared with the α-cumyl cation.
Peroxidase-Catalyzed Oxidative Polymerization of Cresols to a New Family of Polyphenols
Authors: Uyama Hiroshi , Kurioka Hideharu , Sugihara Junji , Komatsu Izuru , Kobayashi Shiro 
Published: July 2006

Abstract
Enzymatic oxidative polymerization of cresols has been performed by using peroxidase catalyst in two types of polymerization solvent: an aqueous organic solution and a reverse micellar solution, to produce polymeric materials. Peroxidases derived from horseradish and soybean were employed as catalyst. The resulting polymers were partly soluble in DMF and DMSO, but, insoluble in water and other common organic solvents. The molecular weight of the DMF-soluble part was measured by GPC as ca. 5000. The solubility and molecular weight were dependent upon the polymerization condition and monomer structure. From IR and UV analyses, the polymer was found to be composed of a mixture of phenylene and oxyphenylene units. The polymer possessed no clear glass transition or melting points. TG analysis exhibited that the present polymers have relatively high thermal stability. The stability of the polymer from o- and m-cresols was better than that from the p-isomer. The polymer remained in around 40 weight % yield at 1000 °C under nitrogen.
The SNAr Reaction of 2,3,5,6-Tetrachloronitrobenzene with Diamines under High Pressure: Formation of Cyclization Products
Authors: Ibata Toshikazu , Zou Xin-Zhuo , Demura Tetsuo 
Published: July 2006

Abstract
The reaction of 2,3,5,6-tetrachloronitrobenzene with ethylenediamine under high pressure gave mainly a 1 : 1-product and a bridged 2 : 1-product by the substitution of a nitro group and/or an o-chlorine atom. The ratio of the products varied depending upon the amount of amine used. Other diamines, such as 1,4-butanediamine cis-and trans-1,2-cyclohexanediamines, m-xylylenediamine, and o-phenylenediamine, gave similar results. On the other hand, N,N′-dimethylethylenediamine and N,N′-dimethyl-1,3-propanediamine gave cyclization products through successive substitutions of an ortho-chlorine atom and a nitro group by the two methylamino groups of a molecule of diamine. N-Methylethylenediamine afforded a 1 : 1-product through the substitution of a nitro group by a primary amino group together with a cyclic 1 : 1-product through substitutions of an o-chlorine atom and a nitro group by secondary and primary amino groups, respectively.
Facile Aromatic Nucleophilic Substitutions Observed for the Triarylcarbenium Ions, [(4-YC6H4)Φ2C]+ [Φ = 2,6-(MeO)2C6H3; Y = MeO, Cl, Me2N, HO]
Authors: Wada Masanori , Watanabe Tetsuya , Natsume Satoko , Mishima Hisashi , Kirishima Katsuhiko , Erabi Tatsuo 
Published: July 2006

Abstract
Triarylmethanols of type (4-YC6H4)Φ2COH {Φ = 2,6-(MeO)2C6H3; Y = MeO, Cl, Me2N} were prepared. The methanol, (4-MeOC6H4)Φ2COH, reacted with acids in a variety of solvents to give the triarylcarbenium salts, [(4-MeOC6H4)Φ2C]X or [(4-HOC6H4)Φ2C]X, or 4-bis(2,6-dimethoxyphenyl)methylene-2,5-cyclohexadienone, O=C6H4=CΦ2, depending on the conditions. These carbenium salts further reacted in alcohols, ROH, to give the triarylmethanes, (4-ROC6H4)Φ2CH (R = Me, Et), where the para-substituent, MeO or HO, was substituted by the solvent, accompanied by a reduction at the central carbon. The methanol, (4-ClC6H4)Φ2COH, also reacted with acid to give the carbenium salt or the triarylmethane, depending on the conditions. While the methanol, (4-Me2NC6H4)Φ2COH, also gave the carbenium salt, [(4-Me2NC6H4)Φ2C]X, it was inert against the formation of the triarylmethane under analogous conditions. It reacted with aqueous sodium hydroxide to give O=C6H4=CΦ2 rather than the original methanol. The para-substituent of [(4-MeOC6H4)Φ2C]X was substituted by di- and monoalkylamines, RR′NH, to give [(4-RR′ NC6H4)Φ2C]X (R,R′ = Me,Me; Et,Et; Me,H; Et,H; Bu,H). While [(4-ClC6H4)Φ2C]X reacted with the dialkylamines to give [(4-RR′NC6H4)Φ2C]X, it reacted with monoalkylamines, RNH2, to give [(4-ClC6H4)Φ2C–NRH2]X. [(4-Me2NC6H4)Φ2C]X was hydrolyzed in the presence of diethylamine to give O=C6H4=CΦ2, but reacted with monoalkylamines to give RN=C6H4=CΦ2.
Fucoxanthin-Pyropheophorbide and Zeaxanthin-Pyropheophorbide Dyads as New Models for Study on Carotenoid-Chlorophyll Excited State Interactions
Authors: Osuka Atsuhiro , Shinoda Satoshi , Marumo Shinji , Yamada Hiroko , Katoh Tetzuya , Yamazaki Iwao , Nishimura Yoshinobu , Tanaka Yoshinori , Taniguchi Seiji , Okada Tadashi , Nozaki Koichi , Ohno Takeshi 
Published: July 2006

Abstract
Fucoxanthin-pyropheophorbide dyads, 3c and 4c, and zeaxanthin-pyropheophorbide dyads, 3d and 4d, were prepared as the first example of natural carotenoid-linked pyropheophorbide. Singlet–singlet energy transfer from carotenoid to pyropheophorbide is more efficient in fucoxanthin-pyropheophorbide dyads than the corresponding zeaxanthin-pyropheophorbide dyads, while the singlet excited state of the pyropheophorbide is quenched more strongly in the zeaxanthin-linked molecules. Marked differences in carotenoid-pyropheophorbide singlet excited-state interactions between fucoxanthin and zeaxanthin strongly suggest their different roles in vivo; antenna function for fucoxanthin and energy-dissipation for zeaxanthin. Both carotenoids similarly quench the triplet excited state of the pyropheophorbide through triplet–triplet energy transfer with rates which depend on temperature and the linkage.
Norbornadiene-Fused Heterocycles: Syntheses and Cycloaddition Reactions of 2-Aryl-4,7-dihydro-4,7-methano-2H-isoindoles and 4,7-Dihydro-4,7-methanoisobenzofuran
Authors: Kobayashi Tomoshige , Suda Hirokazu , Takase Hiroki , Iriye Ryozo , Kato Hiroshi 
Published: July 2006

Abstract
2-Phenyl- and 2-(p-tolyl)-4,7-dihydro-4,7-methano-2H-isoindole were synthesized by treatment of 3-(diethoxymethyl)bicyclo[2.2.1]hepta-2,5-diene-2-carbaldehyde with aniline or p-toluidine, followed by reduction with sodium borohydride and acid-catalyzed cyclization. It was concluded that the previous claim of the synthesis of methanoisoindole derivatives was incorrect. 4,7-Dihydro-4,7-methanoisobenzofuran was prepared by the reduction of the norbornadiene-monocarbaldehyde with sodium borohydride and subsequent treatment with Amberlyst-15. The p-tolylmethanoisoindole reacted with dimethyl acetylenedicarboxylate to give a novel 1 : 3 adduct. On the other hand, in the reaction of the methanoisobenzofuran with N-phenylmaleimide, spontaneous oxidation of the Diels–Alder cycloadduct took place to give exclusively its epoxide.
Interaction of Colloidal Chitin and Chlorophyll a in Ethanol–Water Mixed Solutions
Authors: Takahashi Yasuko , Watanabe Hatsumi 
Published: July 2006

Abstract
The interaction of colloidal chitin [a polysaccharide consisting of β-(1-4)-linked N-acetyl-d-glucosamine (GlcNAc) residues] and chlorophyll a (chl.a) in ethanol–water mixed solutions was investigated by means of vis and UV absorption spectroscopy. The observed facts and discussions are as follows: (i) In ethanol (10%)–water mixed solutions, the reaction rate for complex formation between colloidal chitin and chl.a shows an oscillatory dependence on their concentration ratio. At specific ratios of 7.4 × 1, 2, 4, 8··· of sugar units of chitin to one chl.a molecule, a host–guest complex of colloidal chitin with chl.a is produced. (ii) Another oscillatory phenomenon on the spectral bands of chl.a in the solution is also found as a function of the ethanol concentration. This phenomenon is discussed in terms of cluster formation of ethanol and water molecules in binary mixed solvents. (iii) Upon increasing the ethanol concentration, the host–guest complex of colloidal chitin with chl.a begins to collapse when the ethanol concentration in the solution exceeds a critical value up to which the hydrophilic/hydrophobic hydration equilibrium of the system is attained.
Quinolinium Dichromate Oxidation of Bicyclic Alcohols
Authors: Nongkynrih Irona , Mahanti Mahendra K 
Published: July 2006

Abstract
Kinetic data on the rates of quinolinium dichromate oxidation of some bicyclic alcohols are reported and discussed with reference to the factors that influence the nature of the transition state. The mechanistic pathway has been visualized via the formation of the intermediate chromic ester which undergoes decomposition to give the product. A cyclic transition state is suggested; being a Hückel-type system (4n + 2), this would be an allowed process.
ESR of the Anion Radical of 2,6-Dithioxobenzo[1,2-d:4,5-d′]bis[1,3]dithiole-4,8-dione. Observation of the Satellites of 17O, 13C, and 33S and the Second-Generation Satellites due to Both 13C and 33S in Natural Abundance
Authors: Hirayama Masatoshi , Terasaka Toshitaka , Yamashita Yoshiro , Suzuki Takanori , Miyashi Tsutomu , Usui Yoshiharu 
Published: July 2006

Abstract
ESR study of the anion radical produced by the reduction of the title compound (DTB-BDTD) with potassium metal in 1,2-dimethoxyethane is reported. In addition to the satellites of 17O, 13C, and 33S, the second-generation satellite lines of extremely low intensity, arising from both 13C and 33S isotopes in natural abundance, have been detected. It was found that these satellites vary markedly in line width among each component of its multiplet. This line width effect was used to determine the sign of hfs constants of these magnetic nuclei, and the resulting signs agreed well with those estimated from the spin densities obtained by the McLachlan procedure and the INDO method.
Heavy Atom Effect on 14 Group Nuclear Shielding Constant of SiX4 and CH4−nXn (X = Cl, Br, I; n = 1, 2, 3, 4)
Authors: Endo Kazunaka , Yamamoto Kyonosuke , Okada Hiroaki 
Published: July 2006

Abstract
A sum-over-states third-order perturbation theory using a semiempirical wavefunction parameteric method 3 was applied to 29Si and 13C nuclear magnetic shielding constants of SiX4 and CH4−nXn (X = Cl, Br, I; n = 1, 2, 3, 4), respectively. The other new spin-orbit (LS) term, σLS(A), was proposed to come from the cross term involving the halogen spin-orbit coupling, Fermi I·S interaction and the external field-(carbon or silicon) orbit interaction. The values using the MO method predicted a substantial contribution (25%) of σLS(Si or C) to the σLS(X) as already given. The results agreed fairly well with the experimental values, indicating the importance of the spin-orbit effect on the chemical shifts of molecules containing halogen heavier atoms. The dominant contribution of electronic states to the LS shifts is due to the excitations from all occupied MOs to only all vacant σ*Si(or C)–X antibonding MOs, since the Fermi interaction intervenes between the shift contributions.
Infrared Multiphoton Dissociation Mechanism of 1,2-Dichlorotrifluoroethane in a Molecular Beam
Authors: Yokoyama Atsushi , Yokoyama Keiichi , Fujisawa Ginji 
Published: July 2006

Abstract
The mechanism of the infrared multiphoton dissociation of the title molecule has been studied using photofragmentation translational spectroscopy. The HCl elimination and the C–Cl bond rupture occurred competitively as primary dissociation channels. The HCl elimination reaction accounts for % of the total primary dissociation yields at 16 ± 3 J cm−2. This is consistent with the branching ratio calculated by RRKM theory. A C=C bond rupture of the CF2CFCl molecules and C–Cl bond rupture of C2HF3Cl radicals were also observed as secondary photodissociation processes. The average excitation energy of the dissociating 1,2-dichlorotrifluoroethane molecules was found to be 14—36 kcal mol−1 (1 kcal mol−1 = 4.184 kJ mol−1) above the C–Cl dissociation threshold of the molecules by comparing the observed center-of-mass translational energy distribution for the C–Cl bond rupture with that calculated by Rice–Ramsperger–Kassel–Marcus (RRKM) theory.