bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrasonic Enhancement on the Hydrolysis of Diethyl 1,2-Benzenedicarboxylate
Authors: Yim Bongbeen , Yoo Youngeok , Nagata Yoshio , Maeda Yasuaki 
Published: March 2003

Abstract
The ultrasonic enhancement on the hydrolysis of diethyl 1,2-benzenedicarboxylate results from the dissipated heat when the cavitation micro-bubbles were vigorously collapsed. The effective temperature in a solution depends on the nature of the dissolved gas. The relatively broad region that spreads from the interface of the cavitation micro-bubble plays an important role in the sonolytic hydrolysis of esters.
A 207Pb NMR study of the adducts of triphenyllead chloride and diphenyllead dichloride
Authors: Margolis Lara A. , Schaeffer Charles D. , Yoder Claude H. 
Published: March 2003

Abstract207Pb NMR spectra were used to determine the structure of adducts of triphenyllead chloride and diphenyllead dichloride in CH2Cl2 and CH3CN. The bases included several phosphorus donors, such as tributylphosphine, oxygen donors, such as tributylphosphine oxide, and nitrogen donors, such as pyridine. A number of bidentate bases were also studied. The 207Pb spectra indicate that rapid exchange occurs in the adducts, even at temperatures of −90 °C. The magnitude of the shift relative to the lead acid indicates that all of the bases, including the bidentate bases, form five‐coordinate adducts with triphenyllead chloride. Diphenyllead dichloride forms six‐coordinate adducts, except for the adduct with tributylphosphine, which is five‐coordinate. This is the first report of a five‐coordinate adduct of diphenyllead dichloride. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis of pyrano‐Agarofurans
Authors: Boyer François‐Didier , Descoins Charles , Ducrot Paul‐Henri 
Published: March 2003

AbstractThis paper describes the synthesis of pyrano‐agarofuran tetraol 8. The key step of the synthesis lies in the stereoselectivity encountered in the hydrogenation of precursor 13 because of its peculiar cis‐decalinic conformation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
The Structure of 4‐Benzoyl‐5‐methyl‐2‐phenylpyrazol‐3‐one Oxime and Its Methyl Derivatives
Authors: Holzer Wolfgang , Hahn Katharina , Brehmer Thomas , Claramunt Rosa M. , Pérez‐Torralba Marta 
Published: March 2003

Abstract1H and 13C NMR spectroscopic investigations of 4‐benzoyl‐5‐methyl‐2‐phenyl‐1,2‐dihydro‐3H‐pyrazol‐3‐one oxime (4) and different methylation products thereof (5−11) indicate that 4 exists predominantly as 4‐enaminopyrazolone in [D6]DMSO solution. Single‐crystal X‐ray analysis revealed that in the solid state the same tautomeric structure of 4 was present, and closely resembles that of the corresponding N‐methylamino product (6). Both compounds are stabilised by an intramolecular hydrogen bond between the pyrazolone C=O group and the N‐OH proton. A 1,2‐dihydro‐3H‐pyrazol‐3‐one structure was found in a clathrate of O‐methyloxime 5 and dichloromethane. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
First Partially Intramolecular Palladium‐Catalyzed [2+2+2] Cycloaddition of Benzyne: Application to the Synthesis of Benzo[b]fluorenones
Authors: Peña Diego , Pérez Dolores , Guitián Enrique , Castedo Luis 
Published: March 2003

AbstractThe palladium(0)‐catalyzed reaction of benzyne with suitably functionalized benzodiynes to afford benzo[b]fluorenones is described. The outcome of the reaction is affected by the steric and electronic properties of the diynes and proved to be regioselective when an unsymmetrically substituted aryne is used. This work represents the first example of a partially intramolecular [2+2+2] cycloaddition involving arynes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Easy Synthesis of New Chiral Tetradentate N4 Schiff Bases and Their Use as Ligands for Metal Complexes
Authors: Karamé Iyad , Tommasino M. Lorraine , Faure René , Lemaire Marc 
Published: March 2003

AbstractThe chiral N4 Schiff bases (1R,2R)‐N,N′‐bis(2‐p‐tosylaminobenzylidene)‐1,2‐diaminocyclohexane (H2CyTs, 1), (1R,2R)N,N′‐bis(2‐trifluoromethylsulfonaminobenzylidene)‐1,2‐diaminocyclohexane (H2CyTf, 2), (1R,2R)‐N,N′‐bis(2‐aminobenzylidene)‐1,2‐diaminocyclohexane (3) and (1R,2R)‐N,N′‐bis(2‐nitrobenzylidene)‐1,2‐diaminocyclohexane (4) were synthesized by a new and easy method in high purity and good yields. All the organic compounds were characterized by elemental analysis, mass spectrometry, IR and 1H and 13C NMR spectroscopy. Divalent Co, Cu and Ni complexes 5−8, containing the sulfonamide ligands 1 or 2, have been prepared and characterized. The X‐ray crystal structures of complexes [Co(1R,2R)‐CyTs] (6) and [Ni(1R,2R)‐CyTf] (8) have been solved. These complexes are potential precursors for homogeneous asymmetric catalysis of a variety of reactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Alcohol‐induced memory impairment in trace fear conditioning: A hippocampus‐specific effect
Authors: Weitemier Adam Z. , Ryabinin Andrey E. 
Published: March 2003

AbstractIt has been hypothesized that the amnesic effects of alcohol are through selective disruption of hippocampal function. Delay and trace fear conditioning are useful paradigms to investigate hippocampal‐dependent and independent forms of memory. With delay fear conditioning, learning of explicit cues does not depend on normal hippocampal function, whereas learning explicit cues in trace fear conditioning does. In both delay and trace fear conditioning, the hippocampus is involved in learning to contextual cues, but it may not be entirely necessary. The present study investigates the effects of alcohol on the acquisition of delay and trace fear conditioning in mice, using freezing as a measure of learning. Male C57BL/6J mice were injected with 0.8 or 1.6 g/kg of 20% v/v alcohol and were immediately exposed to eight tone‐footshock pairings in which the conditional stimulus (CS) either coterminated with a footshock unconditional stimulus (US) (delay conditioning) or was separated from the footshock by a 30‐s trace interval (trace conditioning). During trace, but not delay fear conditioning, 0.8 g/kg alcohol impaired learning to a tone CS. This dose also impaired context‐dependent learning in both procedures (although only slightly for trace fear conditioning). The 1.6 g/kg alcohol exerted a nonselective impairment on learning. The impairment by alcohol of learning to a tone CS when it is hippocampus‐dependent, but not when it is hippocampus‐independent provides further support for the hypothesis that alcohol exerts a selective effect on hippocampus‐dependent learning. Hippocampus 2003;13:305–315. © 2003 Wiley‐Liss, Inc.
Involuntary, unreinforced (pure) spatial learning is impaired by fimbria‐fornix but not by dorsal hippocampus lesions
Authors: White Norman M. , Holahan Matthew R. , Goffaux Philippe 
Published: March 2003

AbstractPure spatial learning occurs when rats acquire information about an environment while exploring it in the absence of reinforcers. We previously reported that voluntary, unreinforced exploration of a radial maze retards subsequent reinforced conditioned cue preference (CCP) learning in the same maze. In the present experiment, we examined the effects of involuntary, unreinforced pre‐exposure to a radial maze. During pre‐exposure, rats were moved by an experimenter between the ends of two arms of a radial maze five times in 30 min. This form of pre‐exposure retarded CCP learning, whereas rats that were not pre‐exposed and rats that were pre‐exposed to a maze in a different room displayed normal CCP learning. These findings suggest that some information specific to the maze environment was acquired during involuntary unreinforced pre‐exposure to it. In experiment 2, the retardation of reinforced CCP learning by involuntary unreinforced pre‐exposure was eliminated by fimbria‐fornix lesions made before pre‐exposure but was unaffected by fimbria‐fornix lesions made after pre‐exposure but before training. Large neurotoxic lesions of the dorsal hippocampus made before pre‐exposure had no effect on the retardation of CCP learning, but the rats with these lesions were impaired on a standard test of reinforced spatial learning in a water maze. The lesion effects in experiment 2 are similar to those previously reported for voluntary exploration and suggest that pure spatial learning may occur during both voluntary exploration of and involuntary exposure to an environment in the absence of reinforcers. Pure spatial learning can apparently occur with exposure to two different locations within an environment, but the rats do not have to move between the locations voluntarily. An intact fimbria‐fornix is required for acquisition but not expression of this form of learning. The hippocampus is not involved in this form of learning. Hippocampus 2003;13:324–333. © 2003 Wiley‐Liss, Inc.
Monitoring of S100 homodimerization and heterodimeric interactions by the yeast two‐hybrid system
Authors: Deloulme Jean Christophe , Gentil Benoît Jean , Baudier Jacques 
Published: March 2003

AbstractThe S100 family consists of 19 members, which function as transducers of calcium signals in a tissue‐specific manner. Upon calcium binding, the conformation of many S100 proteins changes dramatically. Several hydrophobic residues are exposed, allowing the S100 proteins to interact with their target proteins, and thereby to transduce calcium signals into specific biological responses. To further elucidate the exact contribution of the S100 calciproteins in the calcium signalling pathways, several groups have applied the yeast two‐hybrid technology to identify putative target proteins for the various S100 calciproteins. Two‐hybrid large screens using S100 proteins as baits have confirmed the biochemical and structural feature of S100, which enable them to form homodimers and the ability of some members to form specific heterodimers in vivo. Yeast two‐hybrid investigations have allowed the identification of conserved hydrophobic residues and domains that are crucial for the stabilization of S100 homo‐ and heterodimers. Furthermore, this method clearly underlines that the homo‐ and heterodimerization mechanisms differ among the members of the S100 family. However, several lines of evidence strongly suggest that two‐hybrid methodology is limited to the analysis of interactions that are calcium‐independent, since no target proteins other than S100 family members themselves have been detected with this methodology. Microsc. Res. Tech. 60:560–568, 2003. © 2003 Wiley‐Liss, Inc.
Gas‐phase ion chemistry in the ternary SiH4–C3H6–PH3 system
Authors: Calderan Stefania , Operti Lorenza , Rabezzana Roberto , Vaglio Gian Angelo 
Published: March 2003

AbstractPropene–phosphine and the silane–propene–phosphine gaseous mixtures were studied by ion trap mass spectrometry. For the binary mixture the variation of ion abundances under different partial pressures and the mechanisms of ion–molecule reactions are reported. Moreover, the rate constants of the main processes were measured and compared with the collisional rate constants to determine the reaction efficiencies. In the ternary silane–propene–phosphine mixture the mechanisms of formation of $\hbox{Si}_{m}\hbox{C}_{n}\hbox{P}_{p}\hbox{H}_{s}^{+}$ ion clusters were elucidated, but the complexity of the system and the low abundances of the ions usually isolated by successive steps prevented the determination of rate constants. The hydrogenated ternary ions are mainly formed by reactions of $\hbox{Si}_{r}\hbox{P}_{s}\hbox{H}_{t}^{+}$ ions with propene, whereas a minor contribution comes from reactions of $\hbox{Si}_{m}\hbox{C}_{n}\hbox{H}_{p}^{+}$ ions with phosphine. The $\hbox{C}_{v}\hbox{P}_{w}\hbox{H}_{z}^{+}$ ions show very low reactivity with silane. The formation processes of these species are discussed in relation to their possible role as precursors of amorphous silicon carbides doped with phosphorus obtained by deposition from properly activated silane–propene–phosphine mixtures. Copyright © 2001 John Wiley & Sons, Ltd.
Analysis of post‐translational modification and characterization of the domain structure of dynamin A from Dictyostelium discoideum
Authors: Schlosser Andreas , Klockow Boris , Manstein Dietmar J. , Lehmann Wolf D. 
Published: March 2003

AbstractThe post‐translational modifications of the 96 kDa protein dynamin A from Dictyostelium discoideum were analyzed using Q‐TOF mass spectrometry. The accurate molecular mass of the intact protein revealed a covalent modification causing an additional mass of 42 Da. The modification could be identified as N‐terminal acetylation by tandem mass spectrometry. Extracted ion chromatograms for the a1 and b1 ion of the tryptic T1 peptide were used to detect the acetylated peptide within 54 nanoelectrospray ionization tandem mass spectra. Owing to the accurate molecular mass of the intact protein, additional covalent modifications could be excluded. In addition to the covalent modification, the domain structure of dynamin A was determined by applying a combination of limited proteolysis, sodium dodecylsulfate polyacrylamide gel electrophoresis, automated tandem mass spectrometry and protein database searching. Copyright © 2003 John Wiley & Sons, Ltd.
A Model for the Elastoplastic Behavior of Isotactic Poly(propylene) Below the Yield Point
Authors: Drozdov Aleksey D. , Christiansen Jesper deC. 
Published: March 2003

AbstractObservations are reported on isotactic poly(propylene) (iPP) in a series of tensile loading‐unloading tests with a constant strain rate at room temperature. A constitutive model is developed for the elastoplastic behavior of a semicrystalline polymer at isothermal uniaxial deformations with small strains. The stress‐strain relations are determined by 5 adjustable parameters which are found by fitting the experimental data.
The stress σ (MPa) versus strain ε in a tensile loading‐unloading test with the maximum strain εmax = 0.09. Circles: experimental data. Solid line: results of numerical simulation.magnified imageThe stress σ (MPa) versus strain ε in a tensile loading‐unloading test with the maximum strain εmax = 0.09. Circles: experimental data. Solid line: results of numerical simulation.
Crystal Orientation Behavior of a Poly(vinylidene fluoride)/Nylon 11 Blend
Authors: Li Yongjin , Kaito Akira 
Published: March 2003

AbstractThe oriented crystallization of poly(vinylidene fluoride) (PVDF) in stretched films of a PVDF/nylon 11 blend was investigated. At low crystallization temperature the c‐axis of the PVDF α‐form was oriented to the orientation axis of the nylon 11 matrix, but c‐axis orientation gradually changed to a‐axis orientation upon increasing the crystallization temperature. Under all crystallization conditions studied, considerable amounts of PVDF in its β‐form with c‐axis orientation were produced as well.
Phase morphology of a stretched film of PVDF/nylon 11 blend observed with confocal laser scanning microscopy.magnified imagePhase morphology of a stretched film of PVDF/nylon 11 blend observed with confocal laser scanning microscopy.
The Synthesis of Mesoporous Silica Spheres by Octylamine Templating
Authors: Singh Puyam S , Kosuge Katsunori 
Published: March 2003

Abstract
Mesoporous silica hollow spheres have been synthesized by a simple route of hydrolysis of acidic tetraethylorthosilicate solution with octylamine surfactant at ambient temperature. The resultant silica spheres have high BET surface areas of 850 to 950 m2/g and mesopore diameters of ca. 2 nm after the samples were calcined in air at 500 °C. The shell thickness of the spheres can be varied by changing the synthesis composition of the reaction system.
Manganese-catalyzed Phenylation of Acetylenic Compounds with a Phenyl Grignard Reagent
Authors: Yorimitsu Hideki , Tang Jun , Okada Kenji , Shinokubo Hiroshi , Oshima Koichiro 
Published: March 2003

Abstract
Treatment of homopropargylic alcohol derivatives or phenylacetylene compounds with phenylmagnesium bromide in the presence of a catalytic amount of manganese(II) chloride afforded phenylated products in good yields with high regio- and stereoselectivities.
Preparation of Alkenyl Sulfides by the Olefination of Thiolesters Using Thioacetals
Authors: Takeda Takeshi , Watanabe Mikako , Nozaki Naoki , Fujiwara Tooru 
Published: March 2003

Abstract
The reaction of thiolesters with titanocene alkylidenes prepared by the treatment of thioacetals with the low valent titanium species Cp2Ti[P(OEt)3]2 produced the corresponding alkenyl sulfides in good yields with moderate to good Z stereoselectivity.
Synthesis of (η5-Cyclopentadienyl)(η4-cyclopenta-2,4-dien-1-thione)cobalt by the Reaction of Cobaltacyclopentadiene Derivative with CS2 in the Presence of Co(I) Complex
Authors: Lee Jong-Chan , Tomita Ikuyoshi , Endo Takeshi 
Published: March 2003

Abstract
(η5-Cyclopentadienyl)(η4-2,3,4,5-tetraphenylcyclopenta -2,4-dien-1-thione) cobalt was obtained by the reaction of (η5-cyclopentadienyl)triphenylphosphinecobalta-2,3,4,5-tetraphenylcyclopentadiene with CS2 in the presence of cobalt(I) complex in quantitative yield, which was also converted quantitatively to (η5-cyclopentadienyl) (η5-1-methylmercapto-2,3,4,5-tetraphenylcyclopentadienyl) cobalticinium iodide by the treatment with methyl iodide.
C-S Bond Cleavage of Allyl Thioethers by Zerovalent Ru Complexes
Authors: Planas Jose Giner , Hirano Masafumi , Komiya Sanshiro 
Published: March 2003

Abstract
The reaction of allyl phenyl or methyl sulfide with Ru(cod)(cot) (1) [cod: 1,5-cyclooctadiene, cot: 1,3,5-cyclooctatriene] in the presence of depe [1,2-bis(diethylphosphino)ethane] causes cleavage of the allyl sulfur bond to afford the cationic π-allyl ruthenium complex, [Ru(η3-C3H5)(depe)2)] [RS] (R = Ph, 2; Me, 3). The thiolate anion is easily exchanged by treatment with NaBPh4.
Synthesis and Reaction of Unsymmetrical Tetraarylbismuthonium Salts. First Isolation of Bismuthonium Salts Bearing All Different Aryl Groups
Authors: Matano Yoshihiro , Miyamatsu Takashi , Suzuki Hitomi 
Published: March 2003

Abstract
Successive treatment of triarylbismuth difluorides (1) with a Lewis acid, Me3SiCN, and aryltributylstannanes (2) in CH2Cl2 gives unsymmetrical tetraarylbismuthonium salts (3) in moderate to good yield. The migratory aptitude of an aryl ligand in [Ph3ArBi+][BF4−] (3a, b) in the C-arylation of 2-naphthol is Ph&gt;p-Tol&gt;p-Ans.
Effect of Lead Oxide Addition to the Photocatalytic Behavior of TiO2
Authors: Sakata Yoshihisa , Yamamoto Tomonori , Gunji Hideki , Imamura Hayao , Tsuchiya Susumu 
Published: March 2003

Abstract
The addition of small amount of lead oxide (less than 0.1 wt%) to TiO2 was effective for improving the photocatalytic activity of H2 production from aqueous methanol. By the addition of Pb2O3 to TiO2, the characteristic ability of photoassisted H2 production was observed under irradiation whose wavelength was longer than 420 nm and was appeared accompanied with the improvement of the photocatalytic activity.
Solid-Solid Catalysis by Ultrafine Crystallites of Heteropoly Compound for Pinacol Rearrangement
Authors: Toyoshi Yasuo , Nakato Teruyuki , Tamura Rui , Takahashi Hiroki , Tsue Hirohito , Hirao Ken-ichi , Okuhara Toshio 
Published: March 2003

Abstract
Cs2.5H0.5PW12O40 consisting of ultrafine crystallites efficiently catalyzes pinacol rearrangement of 1,1,2-triphenyl-1,2-ethanediol at room temperature in solid-solid reaction system, giving the corresponding aldehyde selectively, while p-toluenesulfonic acid, H-ZSM-5, HY, SiO2-Al2O3, SO42−/ZrO2 and Nb2O5 nH2O were inactive. The activity of Cs2.5H0.5PW12O40 in the solid-solid reaction was higher than that in solid-liquid (CHCl3) system.
A Microvoltammetric Study of Transport Process through a Nitrobenzene / Water Interface
Authors: Yamada Hiroshi , Akiyama Shin-ichi , Inoue Takenori , Koike Tohru , Matsue Tomokazu , Uchida Isamu 
Published: March 2003

Abstract
Transport of ferrocenylmethanol and Co(phen)32+ through a nitrobenzene/water interface was examined by an electrochemical method using a microelectrode. The transfer rate of Co(phen)32+ through nitrobenzene / water interface was determined to be 0.05 cm/s by digital simulation analysis. Transfer of ferrocenylmethanol was very fast, with the transfer rate estimated to be larger than 0.1 cm/s.
Synthesis of a Silylene- and Hydride-bridged Re-W Heterobimetallic Complex and Its Photolysis to Form Novel Silenyl-bridged Heterobimetallic Complexes
Authors: Sakaba Hiroyuki , Ishida Kazushige , Horino Hiroshi 
Published: March 2003

Abstract
The reaction of cis-Cp*W(CO)2(MeCN)Me (1) with Cp*(CO)2Re(H)SiMe2H (2) gave the silylene- and hydridebridged heterobimetallic complex Cp*(CO)2W(μ-SiMe2)(μ-H)Re(CO)2Cp* (3). Photolysis of 3 produced an isomeric mixture of novel silenyl-bridged heterobimetallic complexes Cp*(CO)2HW(μ-η1, η2-SiMeCH2)ReH(CO)2Cp* (4).
Activation of Sn-Se Bond: Regioselective Ring Opening Reaction of Epoxides with Tributylstannyl Phenylselenolate in the Presence of a Lewis Acid
Authors: Nishiyama Yutaka , Ohashi Hironori , Itoh Kazuyoshi , Sonoda Noboru 
Published: March 2003

Abstract
When tributylstannyl phenylselenolate (Bu3SnSePh) was allowed to react with epoxides in the presence of BF3·OEt2 as a Lewis acid, the ring opening reaction of epoxides proceeded with complete regioselectivity to afford the β-hydroxy phenylselenides in moderate to good yields.
Monolayers of Calix[4]resorcinarenes with Azobenzene Residues Exhibiting Efficient Photoisomerizability
Authors: Fujimaki Masanori , Matsuzawa Yoko , Hayashi Yuko , Ichimura Kunihiro 
Published: March 2003

Abstract
Azobenzenes tethered from the lower rim of crown conformer of O-octacarboxymethoxylated calix[4]resorcinarenes display efficient E-to-Z photoisomerizability in densely packed monolayers on a water surface, in LB films and in surface-adsorbed monolayers, respectively.
Two-Coordinate Gold(I) Aliphatic Thiolate Complex: The Au-S Distance Is Smaller than the Ag-S One
Authors: Fujisawa Kiyoshi , Imai Sadako , Moro-oka Yoshihiko 
Published: March 2003

Abstract
We prepared the first example of two-coordinate aliphatic monothiolate gold(I) complex. Its structural parameter was compared with that of copper(I) and silver(I) derivatives. The physical properties may be used to differentiate the coordination mode of gold(I) complexes.
Synthesis and Characterization of Triple-decker Sandwich Dinuclear La(III) and Lu(III) Complexes of 2,3,9,10,16,17,23,24-Octabutoxyphthalocyanine
Authors: Takahashi Kazuhiro , Shimoda Jun-ichi , Itoh Makoto , Fuchita Yoshio , Okawa Hisashi 
Published: March 2003

Abstract
The title complexes, [La2(obPc)3] (1) and [Lu2(obPc)3] (2) (H2obPc = 2,3,9,10,16,17,23,24-octabutoxyphthalocyanine), were obtained in a pure form and in good yields and characterized by means of mass, 1H NMR, and UV-visible (vis) spectroscopy and cyclic voltammetry.
Solvent Effect on Intramolecular Electron Transfer Rate of 1,3-Dinitrobenzene Radical Anion
Authors: Hosoi Haruko , Mori Yukie , Masuda Yuichi 
Published: March 2003

Abstract
The solvent induced intramolecular electron transfer rates of the 1,3-dinitrobenzene radical anion in acetonitrile and DMF were determined at various temperatures under negligible ion-ion interaction. For this purpose, a cryptand was used to capture the sodium counter cation, which was produced in the course of the chemical reduction of 1,3-dinitrobenzene. The obtained rates were ca. one order higher than those previously reported using an electrochemical reduction method with supporting electrolyte.
Synthesis of the High-valent Mn Porphyrin Species by Peroxy Acid Oxidation of MnIII Dimers. Characterization of the MnIV2 Species and Evidence of the MnV-MnIII Intermediate
Authors: Ichihara Kanako , Naruta Yoshinori 
Published: March 2003

Abstract
The MnIV porphyrin dimers were synthesized and characterized by UV-vis, ESI-MS, etc. Epoxidation of olefins indicated the transient formation of the MnV (=O) species, which were transformed into the MnIV species by the intramolecular comproportionation between MnV-MnIII moieties.