bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Crystal and Molecular Structure of Potassium u-fac-Bis(N-methyliminodiacetato)cobaltate(III) Sesquihydrate
Authors: Kushi Yoshihiko , Ideno Toshio , Yasui Takaji , Yoneda Hayami 
Published: July 2006

Abstract
The crystal and molecular structure of the title complex has been determined by X-ray analysis. It has been found that the cis-N2O4 octahedron about the cobalt(III) has a large distortion caused by the steric compression between the two adjacent N-methyl groups.
Metal-catalyzed Organic Photoreactions. The Photooxidation of Vinylsilanes and Vinyl Sulfides in the Presence of Iron(III) Chloride, and the Regioselective Synthesis of α-Chloro Ketones
Authors: Sato Tadashi , Tonegawa Tamotsu , Naoi Kunio , Murayama Eigoro 
Published: July 2006

Abstract
The irradiation of a pyridine solution of vinylsilanes or vinyl sulfides in the presence of iron(III) chloride under oxygen produced α-chloro ketones, with a carbonyl group at the olefinic carbon originally bearing a silicon or sulfur atom.
Bis(acetylacetonato)copper Catalyzed Cross-coupling Reaction of Alkenyldicyclohexylborane with 1-Bromo-1-alkyne or 3-Bromo-1-propene
Authors: Hoshi Masayuki , Masuda Yuzuru , Arase Akira 
Published: July 2006

Abstract
Bis(acetylacetonato)copper is capable of catalyzing cross-coupling reaction of alkenyldicyclohexylborane with 1-bromo-1-alkyne or 3-bromo-1-propene to give conjugated (E)-enyne or (E)-1,4-diene in a highly stereoselective manner, respectively.
Homoconjugation in Bicyclo[2.2.1]hept-2-en-7-yl and 1,4-Dihydro-1,4-methanonaphthalen-9-yl Radicals
Authors: Kawamura Takashi , Sugiyama Yoshio , Yonezawa Teijiro 
Published: July 2006

Abstract
2,3-Dimethylbicyclo[2.2.1]hept-2-en-7-yl and 6-methyl-1,4-dihydro-1,4-methanonaphthalen-9-yl radicals are examined wiht ESR. Comparisons of their hyperfine splitting constants with those of bicyclo[2.2.1]hept-2-en-7-yl (1a) and 1,4-dihydro-1,4-methanonaphthalen-9-yl (2a) radicals show that the odd electron on the tervalent carbon atom is delocalized to the extent of 10% into the π system of the vinylene bridge in 1a, and 5% at maximum into the π system of the phenylene bridge in 2a, respectively. This odd eletron delocalization is accompanied by an increase of carbanion character of the tervalent carbon atom. The nonplanarity of their tervalent carbon atoms is discussed in relation to the carbanion character.
The Crystal Structure of 11-(p-Bromophenyl)-11-cyano-12-phenyl-6b-(1-pyrrolidinyl)-6b,6c,11,12a-tetrahydroindeno[1′2′ : 3,4]-cyclopenta[1,2-a]acenaphthylene Acetone Solvate
Authors: Uechi Tetsuo , Tsuge Otohiko , Okita Shigeru , Kanemasa Shuji 
Published: July 2006

Abstract
The title compound crystallizes in the triclinic space group P\bar1 with two fomrula units in a unit cell of dimensions; a=11.621(3), b=15.177(3), c=10.229(2) Å, α=95.63(2), β=105.46(2), and γ=76.43(2)°. The crystal structure was solved by a conventional heavy-atom method and refined by block-diagonal least-squares procedures to give a final R value of 0.050 for 3428 reflections, with Fo&gt;2σ(Fo), collected on a four-circle diffractometer. The bond distance shared between the acenaphthene and the cyclopentane rings is unusually long at 1.596(6) Å, which may result from the additional strain induced by the fusion of these rings. The solvent molecules are disordered in the channel composed of the main molecules.
Synthesis of Mesoionic Triazolopyridine. III. Applications of N-Acyl Mesoionic Triazolopyridines as Acylating Reagents
Authors: Saito Akio , Shimizu Bunji 
Published: July 2006

Abstract
Utility of N-acyl mesoionic triazolopyridines as acylating reagents was investigated concerning with peptide synthesis. Several dipeptides and N-alkoxycarbonyl amino acids were prepared by use of these reagents.
An Improved Resolution of β-Hydroxy-Dl-aspartic Acid on Optically Active Resin Containing l-Lysine or l-Ornithine
Authors: Anpeiji Shigeharu , Toritani Yasunobu , Kawada Kazunori , Kondo Seiji , Murai Shinji , Okai Hideo , Yoshida Hisanobu , Imai Hideo 
Published: July 2006

Abstract
A series of experiments on column chromatography of the optically active resin containing l-lysine or l-or nithine were carried out with pyridinium acetate and ammonium acetate solvent systems as the eluents. threo-β-liydroxy-Dl-aspartic acid was found to be resolved on the optically active resin containing l-lysine with ammonium acetate solvent system; erythro-β-hydroxy-Dl-aspartic acid could be resolved on that containing l-ornithine with pyridinium acetate solvent system. The threo or erythro racemate was resolved on a preparative scale, and the resolution including the complete characterization of enantiomers resolved was first accomplished.
Production of C2(d3IIg) by Controlled Electron Impact on Acetylene, Ethylene, and Ethane
Authors: Ogawa Teiichiro , Ueda Yasuhiro , Higo Morihide 
Published: July 2006

Abstract
The emission spectra produced by controlled electron impact on C2H2, C2H4, and C2H6 have been analyzed to gain insight into the production mechanisms of C2(d3Πg) from the three molecules. There are four thresholds on the excitation function of C2(d3Πg) from C2H2. Its vibrational temperatures are 22000 K for C2H2, 30000 K for C2H4 and 56000 K for C2H6 at an electron energy of 100 eV. Doubly-excited states are involved in the dissociative excitation of C2H2.
The Crystal and Molecular Structure of Albocycline
Authors: Furusaki Akio , Matsumoto Takeshi , Harada Ken-ichi , Suzuki Makoto , Kinoshita Kenji , Hayashi Mitsuo , Nakatsu Kazumi 
Published: July 2006

Abstract
The detailed molecular geometry of albocycline (C18H28O4) has been examined by X-ray crystal analysis. The crystals are monoclinic, with four molecules in a unit cell with dimensions of a=16.177(2), b=9.562(1), c=11.742(2) Å, and β=90.43(1)°; the space group is P21. 3062 unique intensity data were collected on a four-circle diffractometer with graphite-monochromated Mo Kα radiation. The structure was elucidated by the Monte Carlo direct method, using the 30 reflections with the greatest |E| values as the starting set; the 174th random phase set led to the correct solution. The R value reached 0.057 by block-diagonal least-squares refinements. The two crystallographically-independent molecules are connected by two O–H···O hydrogen bonds, forming a hydrogen-bonded dimer. The conformations of the fourteen-membered macrolide rings in these two molecules are considerably different from each other; e.g., great differences of 165, 153, and 108° are found for the torsion angles around the C(4)–C(5), C(6)–C(7), and C(7)–C(8) single bonds respectively.
Ion-chromatographic Behavior of Silica Gels Modified by Poly- and Bis(crown ether)s of Benzo-18-crown-6
Authors: Nakajima Masaki , Kimura Keiichi , Shono Toshiyuki 
Published: July 2006

Abstract
Chromatographic behavior of crown ether modified silicas, in which poly- and bis(benzo-18-crown-6)s were attached covalently to silica gel, was investigated on separation of alkali and alkaline earth metal salts, using water or water/methanol as the mobile phase. Poly- and bis(benzo-18-crown-6)-modified silicas have a large affinity for Cs+, the retention time of alkali metal cations being in the order Li+&lt;Na+&lt;Rb+&lt;K+&lt;Cs+. Various anions having a common cation are separable as well as the metal cations on the modified silicas. Also, alkaline earth metal cations were separated on the stationary phases. The temperature effect of retention of alkali metal chlorides was also examined on bis(benzo-18-crown-6)-modified silica.
Restricted Rotation Involving the Tetrahedral Carbon. XLV. Appearance of a Maximum in the Rotational Barriers of 9-(1,1-Dimethyl-2-phenylethyl)triptycenes at a Medium-sized peri-Substituent
Authors: Yamamoto Gaku , Suzuki Masahiko , Oki Michinori 
Published: July 2006

Abstract
Rotational isomers of seven peri-substituted 9-(1,1-dimethyl-2-phenylethyl)triptycene derivatives were stereoselectively synthesized and classical kinetics on rotational isomerization were studied. While compounds with relatively small peri-substituents (F and OCH3) showed higher barriers than the peri-unsubstituted one, the peri-chloro compound had almost the same barrier with and those carrying bulkier peri-substituents (Br, CH3, and CF3) showed lower barriers than the peri-unsubstituted one. These apparently anomalous phenomena may be explained in terms of large molecular deformation of these highly congested compounds.
Response of a Copper(II) Ion-selective Electrode in Cupric Buffers Based on Macrocyclic Polyamines
Authors: Jyo Akinori , Nagamoto Akiyoshi , Khono Takashi , Ohyoshi Akira 
Published: July 2006

Abstract
The behavior of a copper(II) ion-selective electrode at extremely low activity levels of free copper(II) was examined in copper(II) buffers based on macrocyclic triamines([9]aneN3 and [10]aneN3) and macrocyclic tetramines ([12]aneN4, [14]aneN4, and [16]aneN4). Although the electrode showed the ideal behavior in the buffers based on [12]aneN4 and [16]aneN4, non-ideal behavior was observed for the macrocyclic triamines and [14]aneN4. Thus, the macrocyclic polyamines did not always give the ideal copper(II) buffers for the electrode, in contrast to the case of acyclic polyamines. Stability constants, which were in good agreement with the reported values, could be determined only for [12]aneN4 and [16]aneN4. An application of the cyclic tetramines to complexiometry is also presented.
Regiocontrolled Formation of 4,5-Dihydro-3(2H)-furanones from 2-Butyne-1,4-diol Derivatives. Synthesis of Bullatenone and Geiparvarin
Authors: Saimoto Hiroyuki , Hiyama Tamejiro , Nozaki Hitosi 
Published: July 2006

Abstract
Two new methods for selective hydration of 1,1,4-trisubstituted 2-butyne-1,4-diols (1) to give 4,5-dihydro-3(2H)-furanone derivatives are reported. The first involves selective monoacetylation of the less hindered hydroxyl group of 1 followed by Ag(I)-catalyzed rearrangement and cyclization to give 3-acetoxy-2,2,5-trisubstituted 2,5-dihydrofurans (2). Final hydrolysis yielded 2,2,5-trisubstituted 4,5-dihydro-3(2H)-furanones. Oxidation of the enol acetates 2 with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone gave 3(2H)-furanones. The new method was applied to the synthesis of naturally occurring 3(2H)-furanones such as bullatenone and geiparvarin from the corresponding 2-butyne-1,4-diol derivatives. The second approach is concerned with the synthesis of the opposite regioisomer, 2,5,5-trisubstituted 4,5-dihydro-3(2H)-furanones, from diols 1 with a polymer reagent Hg/Nafion-H.
A Facile Synthesis of Colchiceine Analogues[4-(1-Acetamido-3-arylpropyl)tropolones]
Authors: Nozoe Tetsuo , Takase Kahei , Kawabe Norio , Asao Toyonobu , Yamamoto Hiroshi 
Published: July 2006

Abstract
The condensation of 4-acetyltropolone with various arenecarbaldehydes gave a wide variety of 4-cinnamoyltropolone derivatives in good yield. The same reaction with 2-furaldehyde and cinnamaldehyde also afforded the corresponding 4-substituted tropolones. These products were converted to their oximes (with hydroxylamine hydrochloride), which in turn were hydro genated over 5% Pd/C in acetic acid and then acetylated with acetic anhydride, to yield 4-(1-acetamido-3-aryl-2-propenyl)tropolones. The catalytic hydrogenation of these olefinic products over 10–30% Pd/C in aqueous KOH gave various 4-(1-acetamido-3-arylpropyl)tropolones,which possess a B-ring-open structure of colchiceine. The structures of these products are discussed on the basis of UV, IR, and 1H-NMR spectra.
The Sulfuranyl Radical Structure and Reactions of o-(Thio)benzoyloxyl Radicals Formed by the Decomposition of t-Butyl o-(Thio)perbenzoates Studied by 1H and 13C CIDNP and 17O NMR
Authors: Nakanishi Waro , Kusuyama Yoshiaki , Ikeda Yoshitsugu , Iwamura Hiizu 
Published: July 2006

Abstract
1H and 13C CIDNP signals were observed in the methyl group of o-(methylthio)benzoic acid and the methylene group of 3,1-benzoxathian-4-one (6) during the thermal decomposition of t-butyl o-(methylthio)perbenzoate. The results show that the free “o-(methylthio)benzoyloxyl radical” itself is better represented as the bridged sulfuranyl radical in which most of the spin density is localized at the sulfur atom rather than in the carboxyl. Thermolysis of t-butyl o-(methylthio)- and o-(phenylthio)perbenzoates-carbonyl-17O was carried out and the oxygen labels were detected by 17O NMR spectroscopy preferentially at the carbonyl oxygen of 6 and diphenyl 2,2′-dithiodibenzoate ruling out the zwitterionic radical structure. The migration of phenyl group and the peroxomonosulfate oxidation of o-(phenylthio)benzoic acid are also discussed.
The Formation and Thermal Decomposition of Hydrous Lead(II) Oxide Prepared by the Alkoxide Method
Authors: Narita Eiichi , Kobayashi Makito , Shinjo Hirobumi , Tsuchida Hisashi , Naito Hiroyuki 
Published: July 2006

Abstract
Lead(II) isopropoxide was hydrolyzed by addition to water in order to investigate the effects of temperature, rate of hydrolysis, seeds and anions added in aqueous phase on the formation of hydrous lead(II) oxide. Thermal decomposition of the resulting hydrous lead(II) oxide was also investigated using TG and DTA techniques. It was found that the metastable phase of lead(II) oxide, 3PbO·H2O (tetragonal), was formed only under certain strict conditions, i.e., at higher rate of hydrolysis and at temperatures below 40 °C, whereas the anhydrous lead(II) oxides such as massicot (orthorhombic), litharge (tetragonal), or a mixture of the two were formed under conditions other than those described above. In the presence of massicot seed in aqueous phase, massicot was predominantly formed under the formation conditions of 3PbO·H2O. It was also found that the presence of anions such as citrate and EDTA ions, which have higher complexing ability with PbII ion, facilitated the formation of 3PbO·H2O even under the formation conditions of massicot. In the heating process, 3PbO·H2O was changed to litharge at 168 °C with the release of its water of crystallization and then transformed to massicot at 650 °C. The reaction order and activation energy for the dehydration were 0.9 and 112.6 kJ mol−1, respectively.
Polarographic Studies on Mixed Ligand Complexes of Cadmium with Dl-3-(3,4-Dihydroxyphenyl)alanine and Some Dicarboxylic Acids
Authors: Gupta Nishi , Chandel Chandra Pal Singh , Gupta Prakash Chandra , Gupta Chand Mal 
Published: July 2006

Abstract
The reductiou of Cd(II) has been carried out polarographically in the aqueous solution of Dl-3-(3,4-dihydroxyphenyl)alanine(DOPA). The stability constants were determined for the simple Cd–DOPA system first, and then mixed-ligand complexes of cadmium with DOPA and dicarboxylic acids (oxalic and malic) have been studied. The stability constants of mixed-ligand complexes have been evaluated by the method of Schaap and McMasters. With these data the statistical and electrostatic effects have also been considered.
Partial Reduction of Dinitroarenes to Nitroanilines with Hydrazine Hydrate
Authors: Ayyangar Nagaraj R , Kalkote Uttam R , Lugade Ananda G , Nikrad Pandurang V , Sharma Vasant K 
Published: July 2006

Abstract
Dinitroarenes containing substituents such as hydroxyl and amine groups could be conveniently reduced with 3 molar equivalents of hydrazine hydrate in presence of Raney nickel catalyst in ethanol/1,2-dichloroethane solvent mixture to give a product wherein one of the two nitro groups was reduced to the amino group. The yields of the partial reduction products are good. Under similar conditions alkoxyl substituents in the o,p-position to the nitro groups were displaced by the hydrazino group to give 2,4-dinitrophenylhydrazine as the main product. The details of the reduction reaction are described.
Synthesis and Properties of Crown Compounds Containing Anthraquinone Nuclei
Authors: Nakatsuji Shin’ichi , Ohmori Yuko , Iyoda Masahiko , Nakashima Kenichiro , Akiyama Shuzo 
Published: July 2006

Abstract
2,5,8,20,23,26-Hexaoxa[7.7]-and 2,5,8,11,23,26,29,32-Octaoxa[10.10](1,8)anthraquinonophanes (2 and 3) were synthesized, examined for complexation behavior with alkali and alkaline earth metal cations, and observed to show significant selectivity among the cations studied. The electroreduction of 2 by cyclic voltammetry was studied with there lated compounds.
Synthesis of Cyclic Guanidines Fused with Aromatic Ring through Metal Ion Promoted Cyclization
Authors: Obase Hiroyuki , Nakamizo Nobuhiro , Takai Haruki , Teranishi Masayuki 
Published: July 2006

Abstract
A convenient synthetic method of five- and six- membered cyclic guanidines fused with aromatic ring was presented. 2-Aminoaniline or 2-(aminomethyl)aniline was treated with dimethyl carbonimidodithioates to give isothiourea which was cyclized to cyclic guanidine by using soft metal cations (Ag+, Hg2+).
A Kinetic Study on Denitration of 9,9′-Dinitro-9,9′-bifluorenyl by Tin(II) Chloride in N,N-Dimethylformamide
Authors: Fukunaga Kimitoshi , Kimura Makoto 
Published: July 2006

Abstract
The kinetics of the reductive elimination of nitro groups from 9,9′-dinitro-9,9′-bifluorenyl by tin(II) chloride in N,N-dimethylformamide (DMF) at 20 °C was investigated. It was found that the present elimination is a second-order reaction.
Studies on Bile Salt Solutions. Part 2. Acid Catalyzed Hydrolysis of Trimethyl Orthobenzoate in Solutions of Glycine and Taurine Conjugated Bile Salts
Authors: O’Connor Charmian J , Ch’ng Beng Tatt 
Published: July 2006

Abstract
The reactivity of trimethyl or thobenzoate has been studied, at 310.5 K, in solutions of the glycine and taurine conjugates of the cholanic acids. The rate-concentration profiles are characterized by peaks and troughs which coincide with discontinuities in the slopes of the surface tension-concentration profiles.
Decomposition of 2-Butanol Catalyzed by Iron Oxide and Mixed Oxides Containing Iron
Authors: Jin Tuo , Hattori Hideshi , Tanabe Kozo 
Published: July 2006

Abstract
Three types of binary oxides, Fe2O–TiO2, Fe2O3–ZrO2, and Fe2O3–ZnO, were prepared by a coprecipitation method, and their catalytic behaviors in the decomposition of 2-butanol were examined. The activities and selectivities of the catalysts varied with the type of the oxide with which Fe2O3 was combined, with the content of Fe2O3 in the binary oxides, and with the reduction temperature of the catalysts. Over the Fe2O3–TiO2 catalysts, 2-butanol underwent primarily dehydration and the activity decreased with an increase in Fe2O3 content. Over the Fe2O3–ZnO catalysts, dehydrogenation preferentially occurred, the maximum activity being observed for the catalyst containing 67% Fe2O3. The Fe2O3–ZrO2 catalysts exhibited an intermediate nature between the Fe2O3–TiO2 catalysts and Fe2O3–ZnO catalysts. Reduction of catalysts tended to increase the dehydrogenation selectivity. Reduction also brought about the formation of butane. The maximum formation of butane was observed when the catalysts were reduced with hydrogen at about 350–400 °C. The reaction mechanisms of the formation of butane were elucidated by tracer experiments, and it was concluded that butane was formed by the mechanism involving the first order nucleophilic substitution (SN1) of OH− by H− which was liberated in the dehydrogenation of butanols.
Adsorption of Dodecyltrimethylammonium Chloride-Decylammonium Chloride Mixtures at Water/Air Interface
Authors: Uryu Shozo , Aratono Makoto , Yamanaka Michio , Motomura Kinsi , Matuura Ryohei 
Published: July 2006

Abstract
The surface tension of the aqueous solution of dodecyltrimethylammonium chloride and decylammonium chloride mixture has been measured as a function of the total concentration and composition of the surfactants at 298.15 K under atmospheric pressure. It has been observed that the surface tension decreases with an increase in the composition of dodecyltrimethylammonium chloride at a fixed total concentration. A break point has been observed on the surface tension vs. total concentration curve. By applying the thermodynamic relations, the surface densities of surfactants have been evaluated numerically. It has been proved that the phase transition of the mixed adsorbed film takes place from a gaseous to an expanded state at the break point. By comparing the composition in the adsorbed film with that in the bulk phase, the difference between the compositions has been found to diminish as the surface tension decreases. It has been shown that the mutual relation between the compositions of the gaseous and expanded films at the transition point is described by the two-dimensional phase diagram.
Synthesis and Optical Resolution of [RhIII(S)3(N)3] Type Complexes Containing a Thiolato, Sulfenato, or Sulfinato Donor Group
Authors: Kita Masakazu , Yamanari Kazuaki , Shimura Yoichi 
Published: July 2006

Abstract
Rhodium(III) complexes, [Rh(SCH2CH2NH2)3] and [Rh{S(O)CH2CH2NH2}n{S(O)2CH2CH2NH2}3−n](n=3, 2, 1, and 0), were prepared and optically resolved by means of column chromatography or preferential crystallization of diastereomeric molecular compound with (R,R)-tartaric acid, d-C4H6O6·(−)300CD-[Rh{S(O)CH2CH2NH2}3]·H2O or d-C4H6O6·(+)300CD-[Rh{S(O)CH2CH2NH2}2{S(O)2CH2CH2NH2}]. All the present complexes have only the fac(S) geometry. The (R) configuration of sulfenato group is more stable than the (S) one in the Λ-isomer.
Kinetics of the Thermal Decomposition of Nickel Sulfate
Authors: Onuki Kaoru , Shimizu Saburo , Nakajima Hayato , Ikezoe Yasumasa , Sato Shoichi 
Published: July 2006

Abstract
The rate of thermal decomposition of nickel sulfate was measured in the temperature range from 1003 K to 1078 K. When a powder sample was used, this reaction was characterized as a contracting volume reaction, with apparent activation energy of 296 kJ mol−1. The gaseous products were sulfur trioxide, sulfur dioxide, and oxygen. The composition of the gaseous products was near equilibrium in regard to the reaction, SO3=SO2+1/2 O2, because the nickel oxide formed had high catalytic activity for this reaction.
The Substituent Effects in Thiophene Compounds. II. 1H NMR and IR Studies in Methyl (Substituted 3-Thiophenecarboxylate)s
Authors: Satonaka Hajime 
Published: July 2006

Abstract
The 1H NMR spectra and the IR carbonyl stretching frequencies of methyl (2-, 4-, and 5-substituted 3-thiophenecarboxylate)s are reported. Good linear correlation between the chemical shifts of the ring protons in methyl (5-substituted 3-thiophenecarboxylate)s and those of the corresponding protons in substituted thiophenes was observed. It was found that in methyl (2- and 4-substituted 3-thiophenecarboxylate)s, which have the carbonyl or nitro group in an ortho position, the chemical shifts for the ring protons were considerable affected by the conformation of carbonyl group, the steric hindrance, and the intramolecular hydrogen bonding. Some of methyl (ortho-substituted 3-thiophenecarboxylate)s showed the two C=O stretching bands. They were assigned to anti-s-trans and syn-s-trans forms. The substitutent effects in the C=O frequencies are also discussed. The coupling constants between ring protons of methyl (substituted 3-thiophenecarboxylate)s were correlated very closely with the corresponding ones in substituted thiophenes. The coupling constants in methyl 3-thiophenecarboxylate series were found to vary linearly with the sum of the electronegativities of the substituent on the ring.
Photorearrangements of Some Methyl-substituted Cholest-5-en-3β-ol Nitrites
Authors: Suginome Hiroshi , Maeda Norio , Kaji Makoto , Takakuwa Kyohei 
Published: July 2006

Abstract
Photolysis of 6-methylcholest-5-en-3β-ol nitrite and 4,4,6-trimethylcholest-5-en-3β-ol nitrite in benzene with monochromatic light respectively gave a seven-membered cyclic hydroxamic acid arising from rearrangement albeit in low yields. Photolysis of 3α-methylcholest-5-en-3β-ol nitrite and 3α,4,4-trimethylcholest-5-en-3β-ol nitrite respectively gave a nitroso dimer arising from β-scission.