bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photoinduced Reactions. LXVIII. Photochemical Dehydrogenation of Imidazolines to Imidazoles
Authors: Matsuura Teruo , Ito Yoshikatsu , Saito Isao 
Published: July 2006

Abstract
Imidazolines were found to be dehydrogenated to imidazoles by irradiation at 2537 Å or above 2900 Å in acetone. The n,π* triplet acetone acts as a hydrogen-abstracting agent giving 4- and/or 5-imidazolinyl radicals which in turn are transformed into imidazoles. This scheme is supported by the fact that the AIBN-initiated dehydrogenation of imidazolines gave corresponding imidazoles, that oxygen quenched the photochemical dehydrogenation, and that in some cases coupling products between the imidazolinyl and the acetone ketyl radicals were formed. Various data indicate that the imidazolinyl radical reverts to the parent imidazoline by hydrogen transfer from the acetone ketyl radical during the course of photolysis.
Molecular Structure of N-Methylacetamide as Studied by Gas Electron Diffraction
Authors: Kitano Mitsuo , Fukuyama Tsutomu , Kuchitsu Kozo 
Published: July 2006

Abstract
The bond distances (rg) and angles (rα) in N-methylacetamide have been determined by gas electron diffraction as follows: C–C=1.520±0.005 Å, N–C (methyl)=1.469±0.006 Å, N–C (carbonyl)=1.386±0.004 Å C=O=1.225±0.003 Å, C–H (average)=1.107±0.005 Å, ∠N–C=O=121.8±0.4°, ∠C–N–C=119.7±O.8°, ∠C–C–N=114.1±1.5°, ∠H–C–H(average)=110.4±2° and ∠H–N–C(carbonyl)=110±5°. In comparison with the molecular structure in the crystal, the N–C(carbonyl) bond is about 0.10 Å longer, whereas the C–C and C=O bonds are about 0.02 and 0.01 Å shorter, respectively. The two methyl groups are in the trans conformation about the N–C (carbonyl) bond, no other conformer being observed.
The Electrochemical Fluorination of Dithiols and Cyclic Sulfides
Authors: Abe Takashi , Nagase Shunji , Baba Hajime 
Published: July 2006

Abstract
The electrochemical fluorination of dithiols [1,4-butanedithiol (I), 1,5-pentanedithiol (II), and 3-oxapentane-1,5-dithiol (III)] and cyclic sulfides [tetrahydrothiophene (IV), 2-methyltetrahydrothiophene (V), 3-methylthiophene (VI) and tetrahydrothiopyran (VII)] was conducted. Dithiols afforded the corresponding fullyfluorinated analogs of the starting dithiol (SF5(CF2)n SF5; n=4 from 1,5 from II; SF5CF2CF2OCF2CF2SF5 from III) and the cyclic products (perfluorotetramethylenesulfur tetrafluoride from I, perfluoro-2-methyltetramethylenesulfur tetrafluoride, perfluoro-3-methyltetramethylenesulfur tetrafluoride, and perfluoropentamethylenesulfur tetrafluoride from II, and perfluoro-4-oxapentamethylenesulfur tetrafluoride from III). The corresponding perfluoro-cyclic sulfur(VI) compounds were obtained from IV, V, VI, and VII in reasonable yields. The novel perfluoropolymethylene bis(sulfur pentafluoride)s are transparent heavy liquids. Their physical properties and 19F NMR and IR data are reported.
The Calculation of the π-Electron Orbital Energies of the Allyl Cation, Butadiene, and Cyclic Polyenes by Means of Green’s Function Method
Authors: Shimada Katsumi , Okido Sadao , Tanimoto Osamu 
Published: July 2006

Abstract
Green’s function matrix method for the calculation of the orbital energies of π-electron systems, which has been discussed in previous papers, is applied to the allyl cation, butadiene, rectangular cyclobutadiene, and cyclic polyenes with various molecular lengths. The higher-order correction for the Hartree-Fock orbital energies are calculated, and in the case of butadiene the theoretical value of the ionization potential is discussed in comparison with the experimental data. The relation between the higher-order correction effect and the molecular length is illustrated in the cases of the cyclic polyenes. In particular, the breakdown of perturbation calculation based on the Hartree-Fock orbitals occurs in the case of the C30H30 molecule.
Kinetics of the Aquation of Iron(III) Monophenolate Complexes; Absence of the Acid-dependent Path
Authors: Nakamura Koichi , Tsuchida Toshihiko , Yamagishi Akihiko , Fujimoto Masatoshi 
Published: July 2006

Abstract
The complex formation between Fe(III) and 10 kinds of phenols was investigated using a stopped-flow apparatus. It was confirmed that the reaction rate is acid-independent in the acid region 0.01–1.0 m. A mechanism for the aquation of the iron (III)-phenol complex is proposed in which a proton transfers intramolecularly from a co-ordinated water molecule to a phenolate ion, viz., Fe(OH2)5A2+→Fe(OH2)4(OH)·AH2+. From the observed isotope effects it was concluded that the state of a proton of HA in Fe(OH2)4(OH)·AH2+ differs from that in a free phenol.
NMR Study of Amino Acids and Their Derivatives. V. Structures and Formation Constants of Zinc-l-Aspartic Acid Complexes in Aqueous Solution
Authors: Ishizuka Hidehiro , Yamamoto Takeo , Arata Yoji , Fujiwara Shizuo 
Published: July 2006

Abstract
NMR spectra of l-aspartic acid coordinated with Zn ions were measured in aqueous solution at various pH values. Three species of zinc-l-aspartic acid complexes were identified i.e., 1 : 1 zinc–l-aspartic acid(zwitter ionic form) complex (MAH), and 1 : 1 and 1 : 2 zinc–aspartic acid(anionic form) complexes (designated as MA and MA2, respectively). It is shown that, in MAH, the amino acid coordinates with Zn as a monodentate ligand, whereas in MA and MA2, approximately 65% of the molecules of amino acid coordinate as a tridentate ligand. From the chemical shift data, the equilibrium constants for these complexes are determined as follows: pKa-(MAH)=5.3±0.2 and logK2=4.5±0.2 where Ka(MAH)=[MA][H+]/[MAH] and K2=[MA2]/[MA][A].
Heat Capacity of Tetramethylsilane in the Region from 2 to 26 K and Premelting Range
Authors: Shinoda Takako , Enokido Hisae , Maeda Yoji , Tomita Hiroshi , Mashiko Yo-ichiro 
Published: July 2006

Abstract
The heat capacity of tetramethylsilane was measured at temperatures from 2 to 26 K and in the premelting temperature range for two crystalline forms. There are two crystalline forms in solid tetramethylsilane. The heat of fusion and triple point temperature of a stable form were found to be 1611.2±0.9 cal/mol and 174.049 K, while those of a metastable form to be 1396.0±0.8 cal/mol and 170.981 K. Tetramethylsilane was highly purified by preparative gas chromatography. The amount of impurity in the specimen of Si(CH3)4 was estimated to be 0.0046 mol% from measurement of the melting point range for two crystalline forms. The Debye characteristic temperature at 0 K, θD(0), was derived from low temperature heat capacity data, and the θD(T)⁄θD(0) curve was compared with those for C(CH3)4 and CF4. Despite high purity, Cp values for two crystalline forms in the region below melting points increases abnormally with the rise of temperature. The phenomena were interpreted as due to effects of formation of vacancies in the crystals and of melting accompanied by molecular orientation transition; analysis of heat capacity curves for the two crystalline forms was made in the region befow the melting point.
Asymmetric Hydrogenation of C=O Double Bond with Modified Raney Nickel Catalyst. XXV. Contributions of pH-Adjusting Reagents in the Asymmetric Hydrogenation
Authors: Tanabe Tadashi , Okuda Kazuo , Izumi Yoshiharu 
Published: July 2006

Abstract
In the asymmetric hydrogenation of methyl acetoacetate with modified Raney nickel catalysts, the effects of pH-adjusting reagents were studied using ds-tartaric acid, ls-2-hydroxyisovaleric acid, l-glutamic acid, and l-aspartic acid as the modifying reagents. The effects of various metal ions and ammonium ions were investigated at pH 5.0. The asymmetric activity of the catalyst modified with the 2-hydroxy monocarboxylic acid or 2-amino dicarboxylic acid was not affected by the pH-adjusting reagents. However, 2-hydroxy dicarboxylic acid was markedly influenced by the reagents. The univalent metal ion was more effective than divalent or ammonium ions. Sodium hydroxide was the best pH-adjusting reagent. The adsorption state of the modifying reagent was discussed on the basis of the effects of the pH-adjusting reagent.
Chemistry of Cyanoacetylenes. Part XIV. One-step Synthesis of Some Ethynyl Heterocycles and Their Reactions with Diazomethane
Authors: Sasaki Tadashi , Eguchi Shoji , Sugimoto Michio 
Published: July 2006

Abstract
The Ritter reaction of cyano- and chlorocyanoacetylene with appropriate substrates provided a facile one step synthesis of 4,4-dimethyl-2-ethynyloxazoline (5), 4,4,6-trimethyl-2-ethynyl (7) and -2-chloroethynyl-5,6-dihydro-1,3-oxazine (8), 5,5-dimethyl-3-isopropylidene-2-ethynyl- (10) and -2-chloroethynyl-1-pyrroline (11). On treatment with diazomethane, 7 gave 4,4,6-trimethyl-2-(4-1H-pyrazolyl)- (13) and -2-(3-1H-pyrazolyl)-5,6-dihydro-1,3-oxazine (14) in 42 and 40% yields respectively, while 8 afforded only 4,4,6-trimethyl-2-[3-(4-chloro-1-methyl)-pyrazolyl]-5,6-dihydro-1,3-oxazine (15) in 52% yield. On the other hand, 10 gave 5,5-dimethyl-3-isopropylidene-2-(3-1H-pyrazolyl)-1-pyrroline (16) in 64% yield and 11, 5,5-dimethyl-3-isopropylidene-2-[3-(4-chloro-1-methyl)-pyrazolyl]-1-pyrroline (17) in 16% yield.
Synthetic Studies by the Use of Carbonates, II. An Easy Method of Preparing Cyclic Carbonates of Polyhydroxy Compounds by Transesterification with Ethylene Carbonate
Authors: Komura Hajime , Yoshino Teruo , Ishido Yoshiharu 
Published: July 2006

Abstract
Transesterification reactions of polyhydroxy compounds, such as 1-O-p-nitrobenzoyl-, 1-O-benzylglycerols, 1,2;3,4-di-O-, 3,4-O-isopropylidene-d-mannitols, 1,2-O-isopropylidene-α-d-glucofuranose, uridine, 1,2;5,6-di-O-isopropylidene-d-mannitol, and d-mannitol, by ethylene carbonate were attempted; the corresponding products were obtained in good yields except in the case of uridine, which gave 2,2′-anhydro-1-β-d-arabinofuranosyluracil.
Structural Effects on the Properties of Nonionic Surfactants. II. Acetal Type Homogeneous Nonionics Having Polyoxyethylene Chains Terminated with Methoxyl Group
Authors: Takahashi Hideo , Kuwamura Tsunehiko 
Published: July 2006

Abstract
A series of homogeneous acetal nonionics (AGM types) with the general formula RCH[O(C2H4O)mCH3]2 were prepared from higher alkanals (C8–C14) and several pure polyoxyethylene (POE) glycol monomethylethers (m: 3–6), and purified by repeated distillation in vacuo. Cloud point, critical micelle concentration (CMC) and molecular area on adsorbed film were determined for AGM types. The results were compared with data on homogeneous acetals (AG types) having terminal hydroxyl in POE chains. The result confirms the suggestion that two POE chains in AG strongly interact with each other owing to intramolecular hydrogen-bonding and intertwisting. AGM are extremely low foaming nonionics although their ability to lower surface tension is comparable to that of the usual nonionics.
The Cation-radical Salts Derived from Benzo- and Dibenzo-phenothiazines
Authors: Matsunaga Yoshio , Suzuki Yukio 
Published: July 2006

Abstract
The chloride, iodide, and perchlorate of benzo- and dibenzo-phenothiazine cation-radicals have been prepared by the reaction of an equimolar mixture of the thiazine and its S-oxide with an appropriate acid. The vibrational spectra of the products have been found to be in close agreement with those of the bromides made by the familiar oxidation of thiazines with bromine. The results of electronic spectral and ESR measurements have furnished further support for our conclusion that the thiazine cation-radical salts can be prepared by the above-mentioned reaction. The electronic spectra of the iodides of benzophenothiazines have been found to differ markedly from those of other salts and to bear a resemblance to those of the low-resistivity iodine complexes.
Thermodynamic Properties of Some Isomeric Butyl Alcohol Mixtures
Authors: Murakami Sachio , Benson G C 
Published: July 2006

Abstract
Molar excess enthalpies and molar excess volumes are reported for binary mixtures of n-butyl alcohol with isobutyl alcohol, sec-butyl alcohol, and t-butyl alcohol. All of the measurements were carried out at 25°C except for the excess enthalpies of n-butyl alcohol–t-butyl alcohol which were determined at 26°C. Interpretation of the results in terms of a lattice model was investigated.
The Coupled Perturbed Hartree-Fock Calculations of the Magnetic Susceptibility for Some Nonbenzenoid Aromatic Hydrocarbons
Authors: Mikami Yasushi , Miyai Seiko , Nakajima Takeshi 
Published: July 2006

Abstract
The semi-empirical SCF MO method is applied to the calcutations of the magnetic susceptibility of the π-electron systems of several nonbenzenoid aromatic hydrocarbons. To avoid origin-dependent results, a method actually equivalent to Hall and Hardisson’s one which is currently called the coupled perturbed Hartree-Fock method is used. With the best-fit parameters, the calculated results are in good agreement with the available experimental values except for the case of aceheptylene.
Liquid-phase Oxidation Catalyzed by Cu(II)–Cl System, I. Oxidation of Cyclohexene
Authors: Imamura Sei-Ichiro , Banba Toshiaki , Takegami Yoshinobu 
Published: July 2006

Abstract
Oxidation of cyclohexene catalyzed by Cu(II)–Cl systems was carried out in glacial acetic acid. The oxidation of cyclohexene with cupric chloride was highly accelerated by addition of various alkali chlorides. The decomposition of cyclohexenyl hydroperoxide, an intermediate product of the oxidation, was also accelerated by this catalyst system. Salts other than alkali chlorides had little effect. It was concluded that the activation of copper catalyst was due to the chloride ions which form a complex with copper. In the course of the reaction the catalyst loses its activity through ligand exchange with solvent molecule, acetic acid.
An Electron Spin Resonance Study of the Steroid Conformation –6-Oxohelvolic Acid (Triketone)–
Authors: Fujisawa Takiko , Okuda Shigenobu , Fujita Yuzaburo 
Published: July 2006

Abstract
The triketone (6-oxohelvolic acid (IIa) or its tetrahydro-derivative (IIb)) was readily oxidized in air into the anhydride (IIIa or b) in an alkaline solution; it spontaneously turned red or deep green and then gradually lost its color. In this reaction process, the presence of a relatively stable intermediate radical was confirmed by the ESR measurement. As a result of an analysis of the well-resolved proton hyperfine structure of this radical, it was explained that the structure of helvolic acid is of the protostane type: that is, it is a distinctive structure of the trans-fusion of the A/B ring juncture and a boat form of the B-ring. A reasonable oxidation mechanism including this intermediate radical was presented.
A Novel Degradation Pathway of l-Ascorbic Acid under Non-oxidative Conditions
Authors: Goshima Kazuaki , Maezono Norihide , Tokuyama Kanji 
Published: July 2006

Abstract
The degradation of l-ascorbic acid (1) in methanol was studied in the presence of boron trifluoride-etherate under non-oxidative conditions. Two epimeric compounds containing an acetal group (7a and 7b) were isolated as the intermediates and 2-methoxalylfuran (13) the final product. From the result, the degradation pathway of 1 in methanol was proposed to be 1→7→13. By analogy with the proposed pathway, one in an aqueous acid was also presented.
Autoxidation of Aromatic Hydrocarbons Catalyzed with Cobaltic Acetate in Acetic Acid Solution. II. Oxidation of Ethylbenzene and Cumene
Authors: Kamiya Yoshio , Kashima Mikito 
Published: July 2006

Abstract
The oxidation of ethylbenzene and cumene catalyzed with cobaltic acetate in acetic acid was studied kinetically in order to elucidate the reaction mechanism and the roles of cobaltic salt. The maximum absorption rate of oxygen as well as the maximum reduction rate of Co(III) in the oxidation of ethylbenzene or cumene were of first order with respect to the initial concentration of hydrocarbon, of inverse first order with respect to the initial concentration of Co(II), and of second order with respect to the initial concentration of Co(III). The kinetic equations are therefore just the same as in the case of toluene, but d[Co(III)]/d[O2] gave a quite different average value of 3.8, showing that almost no regeneration of Co(III) from Co(II) due to oxidation with peroxidic compounds occurred. Both rates were remarkably accelerated by the addition of sodium acetate and also influenced by a small amount of water. The order of oxygen absorption rate in oxidation was toluene&gt;ethylbenzene&gt;cumene in contrast to the order of hydrogen abstraction rate by peroxy radicals. The apparent activation energy for these hydrocarbons was found to be 10.1 kcal mol−1.
Phase Transition in the Ionic Modification of Phosphorus Pentachloride, [PCl4][PCl6]. Chlorine Nuclear Quadrupole Resonance Study
Authors: Chihara Hideaki , Nakamura Nobuo 
Published: July 2006

Abstract
Chlorine-35 nuclear quadrupole resonance frequencies in the ionic crystal PCl4+·PCl6− were redetermined. Ten resonance lines were found and their temperature dependences were measured below the second order phase transition point at 102 K. The splitting Δvi in the resonance lines in the low temperature phase showed a similar temperature dependence as the order parameter. This was accounted for by a librational soft mode theory based on an anharmonic coupling between molecular or ionic librational modes in the crystal.
Synthesis of Pyrazole Derivatives Using 1-Benzoyl-1-phenylhydrazine
Authors: El-Sayed Abdou Ahmed , Ohta Masaki 
Published: July 2006

Abstract
Condensation of 1-benzoyl-1-phenylhydrazine (I) with β-ketoesters and β-diketones was investigated. Reaction of I with ethyl acetoacetate, ethyl benzoylacetate and diethyl acetonedicarboxylate in the presence of phosphorus pentoxide afforded the corresponding hydrazones which were easily cyclized by sodium hydroxide to give pyrazole derivatives. Reaction of I with acetylacetone proceeded to give hydrazone without condensing agent. 4-Carboxy-1,5-diphenylpyrazol-3-ylacetic acid and its mono- and diester were also prepared.
Heat Capacity of Solid Phosphorus Pentachloride between 4 and 150 K. Nature of the Transition at 102 K.
Authors: Chihara Hideaki , Nakamura Minoru , Masukane Kazuyuki 
Published: July 2006

Abstract
Molar heat capacity of solid P2Cl10 was measured between 4 and 150 K with an adiabatic calorimeter, with particular attention to the phase transition at 102.0±0.2 K. The heat and entropy of the transition were 148±3 Jmol−1 and 1.67±0.03 JK−1mol−1. Shape and magnitude of the anomalous heat capacity depend on the method of preparation. Anomaly in the heat capacity begins at about 75 K, rises gradually to a maximum of 9.12±0.08 JK−1mol−1 at 102.0 K and tails off at about 110 K. The shape of the excess heat capacity curve can be explained satisfactorily by the librational soft-mode theory which assumes that PCl6 anions tend to change equilibrium orientation with temperature.
Studies of Peptide Antibiotics. XXVIII. Syntheses of Sesquigramicidin S and Digramicidin S
Authors: Matsuura Shuji , Waki Michinori , Kato Tetsuo , Izumiya Nobuo 
Published: July 2006

Abstract
Two macro-ring analogs of gramicidin S, namely cyclo(–l-Val–l-Orn–l-Leu–d-Phe–l-Pro–)3 (sesquigramicidin S) and cyclo(–l-Val–l-Orn–l-Leu–d-Phe–l-Pro–)4 (digramicidin S), were prepared to investigate the influence of the ring size of gramicidin S for antibacterial activity. Several linear analogs such as H–(l-Val–l-Orn–l-Leu–d-Phe–l-Pro)n–OH (n=2, 3 and 4) were also prepared as reference compounds. All these macroring and linear analogs showed weaker activity than gramicidin S and synergistic property when each of the analogs is mixed with gramicidin S. Measurements of optical rotatory dispersion were made with these analogs and gramicidin S in solvents of ethanol and 8 M aqueous urea. From these experiments, it was suggested that the mode of antibacterial action of the macro-ring analogs and their conformations are similar to those of the linear analogs.
Synthetic Studies of Amino Acids by the Use of Copper(II) Complex. III. Syntheses of Several 2-Amino-2-deoxyaldonic Acids by the Use of Bisglycinato- and N-Pyruvylideneglycinatoaquocopper(II)
Authors: Ohdan Shohji , Okamoto Toshiro , Maeda Sadao , Ichikawa Tetsuya , Araki Younosuke , Ishido Yoshiharu 
Published: July 2006

Abstract
A comparative study of the relative reactivity of bisglycinatocopper(II) and N-pyruvylideneglycinatoaquocopper(II) in a base-catalyzed condensation reaction with aldehydo sugar derivatives concluded that the latter complex is much more reactive than the former. This reaction was found to proceed with a considerably high stereoselectivity to afford blocked 2-amino-2-deoxyaldonic acids with a threo configurational relationship between C–2 and C–3, and between C–3 and C–4. The resultant products were converted to the corresponding free 2-amino-2-deoxyaldonic acids in good yields by deblocking them with Amberlite IR-12OB(H form).
Single Crystal Electron Spin Resonance Spectra of Magnetically Dilute Copper(II) Ion in Some Five-coordinate Adducts of Zinc(II) β-Diketonate Complexes
Authors: Misumi Seizo , Isobe Toshiyuki , Sugiyama Kuniyoshi 
Published: July 2006

Abstract
The single crystal ESR spectra of some five-coordinate adducts of copper(II)-doped zinc(II) β-diketonate complexes [Cu/Zn(acac)2H2O], [Cu/Zn(acac)2γ-pic], [Cu/Zn(bzac)2MeOH], and [Cu/Zn(bzac)2py] (acac=acetylacetone anion, bzac=benzoylacetone anion, py=pyridine, γ-pic=γ-picoline, MeOH=methanol) were measured at room temperature. The principal values of the g tensor and A tensor of 63Cu were calculated. The single crystal g-values of all the adducts suggested a dx2−y2 ground state for the approximately square-based pyramidal structure, and were found to be consistent with crystallographic data. In the single crystals of [Cu/Zn(acac)2H2O] and [Cu/Zn(bzac)2py], two magnetic centers were determined, this being the first time for them to have been found by ESR study.
Charge-transfer and Proton-transfer in the Formation of Molecular Complexes. VIII. Benzidine–2,4-Dinitrophenol Complexes
Authors: Saito Gunzi , Matsunaga Yoshio 
Published: July 2006

Abstract
The simultaneous operation of charge-transfer and proton-transfer interactions was demonstrated in the orange complex and also in the brown complex of a 3 : 2 composition. The former one quickly becomes the yellow monohydrate of the 1 : 1 salt upon exposure to air.
Dielectric Relaxation and Molecular Structure. XII. Dipole Moments and Dielectric Relaxation Times of Rigid Molecules in Solutions
Authors: Nagai Tohru , Koga Yoshinori , Takahashi Hiroaki , Higasi Keniti 
Published: July 2006

Abstract
Dielectric constants and losses of anthrone, xanthone, fluorenone and ten other rigid and almost rigid organic molecules were measured at the frequency of about 100 GHz in benzene at 25 °C. The dielectric relaxation times τ(1) and τ(2) and the dipole moments μ of these molecules were obtained and discussed.
Spectral Difference of the A and B Forms of Deoxyribonucleic Acid
Authors: Nishimura Yoshifumi , Morikawa Kosuke , Tsuboi Masamichi 
Published: July 2006

Abstract
Infrared absorption spectrum of an oriented film of deoxyribonucleic acid from Micrococcus lysodeikticus has been examined in its A and B forms. In the A form a weak band was observed at 807 cm−1, while in the B form this is absent and a broad and weak band appears at 832 cm−1.
Electronic Excited States of the Intramolecular Exciplex and Charge-transfer Complex in (9,10-Dicyanoanthracene)(CH2)3-(Naphthalene)
Authors: Itoh Michiya , Mimura Tsutomu , Okamoto Toshihiko 
Published: July 2006

Abstract
In the previous paper two kinds of fluorescences due to the intramolecular exciplex (above ∼200 K) and the charge-transfer complex (below ∼160 K) were reported in a nonpolar solution of the (9,10-dicyanoanthracene)(CH2)3-(naphthalene) systems. The fluorescence quantum yields as well as the fluorescence lifetimes of the exciplex and CT complex determined at several temperatures show a discontinuous change from room temperature to 77 K. The radiative and nonradiative decay constants of these fluorescent states suggest that the radiative decay in the exciplex is comparable with the nonradiative decay, while the nonradiative process is predominant in the excited state of the CT complex.