bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimation of partial discharge onset characteristics in gases around a triple junction
Authors: Hara Masanori , Kurihara Takashi , Kozuru Susumu , Suehiro Junya , Hayashi Noriyuki 
Published: April 2003

AbstractA new method of estimating partial discharge onset conditions in gases around a triple junction is proposed. The effectiveness of the method based on the Paschen curve and the potential distribution along the interface between a solid insulator and gas is confirmed experimentally in air at room temperature. The partial discharge onset conditions in air and SF6 gas under different pressures at room temperature and in cryogenic nitrogen and helium gases at saturation temperature and atmospheric pressure are estimated. The partial discharge intensity is discussed on the basis of the proposed method. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 144(1): 1–11, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10175
A method for parametrized contingency‐constrained optimal power flow (PCCOPF)
Authors: Tanabe Ryuya , Tada Yasuyuki , Sekine Yasuji 
Published: April 2003

AbstractThis paper presents a method for Parametrized Contingency Constrained Optimal Power Flow (PCCOPF) whose formulation can discriminate unpreventable contingencies, determine the existence of feasible solutions for postcontingencies, and analyze the feasible solution for the contingencies in terms of static sense. The proposed formulation is based on parametrized contingency constraints in which each contingency parameter represents the achievement ratio of each selected contingency. In the formulation, not only parametrized contingency constraints are given by a set of equality constraints which is modified power flow equations, but also the objective is maximization of the sum of the achievement ratios of selected contingencies. Since contingency parameters are treated as decision variables in the proposed method, the information on unsolvability with respect to each contingency can be efficiently obtained. The feasibility and effectiveness of the proposed method are demonstrated on test problems with 4‐bus and 71‐bus systems. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 144(1): 21–31, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10182
Nonlinear modeling of a permanent‐magnet induction machine
Authors: Fukami Tadashi , Nakagawa Kenichi , Hanaoka Ryoichi , Takata Shinzo , Miyamoto Toshio 
Published: April 2003

AbstractThis paper presents the nonlinear modeling of a permanent‐magnet induction machine (PMIM). The PMIM has a permanent‐magnet (PM) rotor that is free to rotate inside a squirrel‐cage rotor. The internal self‐excitation from this PM rotor allows the PMIM to operate at a higher power factor. Utilizing a duality between magnetic and electric circuits, an electrical equivalent circuit that can accurately include the nonlinearity of the excitation circuit is derived. Based on this equivalent circuit, a measuring method of circuit parameters and a calculation method of the steady‐state performance are explained. In addition, the generating characteristics of the PMIM in the grid‐connected mode are theoretically calculated to verify the validity of the derived equivalent circuit, and the results are confirmed through experiments. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 144(1): 58–67, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10189
Combining Magnets and Dielectrics: Crystal Chemistry in the BaO−Fe2O3−TiO2 System
Authors: Siegrist Theo , Vanderah Terrell A. 
Published: April 2003

AbstractPhases observed in the BaO−Fe2O3−TiO2 system are classified and described in terms of the framework of close‐packed {O,Ba/O} layers, with the transition metal atoms either in octahedral (titanium and iron) or in tetrahedral (iron only) sites. The resulting crystal chemistry features new combinations of structural features intermediate between the magnetic barium hexaferrites and the dielectric barium polytitanates, and thus gives rise to phases with potentially useful magnetic/dielectric properties. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Efficient Energy Transfer in Supramolecular, Hydrogen‐Bonded Polypyridylruthenium‐Osmium Complexes
Authors: Rau Sven , Schäfer Bernhard , Schebesta Sebastian , Grüßing André , Poppitz Wolfgang , Walther Dirk , Duati Marco , Browne Wesley R. , Vos Johannes G. 
Published: April 2003

AbstractHydrogen bond association between ruthenium bibenzimidazole and carboxylated polypyridylosmium complexes results in stable supramolecular aggregates. The determined stability constant of logK ≈︁ 6 ± 0.3 allows efficient energy transfer from the ruthenium to the osmium moiety. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
The First Azaindatrane and Unprecedented Structural Features
Authors: Shutov Pavel L. , Karlov Sergey S. , Harms Klaus , Poleshchuk Oleg Kh. , Lorberth Jörg , Zaitseva Galina S. 
Published: April 2003

AbstractThe reaction between [In(NEt2)3]2 and N(CH2CH2NMeH)3 yields the N,N′,N′′‐trimethylazaindatrane dimer [N(CH2CH2NMe)3In]2 (1). The composition and structure of 1 were established by 1H and 13C NMR spectroscopy as well as by an X‐ray diffraction study. The X‐ray structure shows that both indium atoms are pentacoordinate, with widely differing In−N distances. The structural parameters of 1 were compared with those obtained from a computational study. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Sequential Nucleophilic−Electrophilic Reactions Selectively Produce Isomerically Pure Nona‐B‐Substituted o‐Carborane Derivatives
Authors: Barberà Gemma , Teixidor Francesc , Viñas Clara , Sillanpää Reijo , Kivekäs Raikko 
Published: April 2003

AbstractNine equal substituents on the intensively studied o‐carborane have been obtained for the first time by a combined nucleophilic‐electrophilic reaction sequence. Iodine and methyl groups have been introduced to prove the generality of the method. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A Three‐Dimensional Framework of Novel Vanadium Clusters Bridged by [Ni(en)2]2+: Ni(en)3{VIV11VV5O38 Cl [Ni (en)2]3}·8.5H2O
Authors: Pan Cheng‐Ling , Xu Ji‐Qing , Li Guang‐Hua , Chu De‐Qing , Wang Tie‐Gang 
Published: April 2003

AbstractThe hydrothermal reaction of V2O5, H2C2O4·2H2O, KOH, en and NiCl2·6H2O yields a new three‐dimensional open‐framework solid. The extended structure consists of a three‐dimensional network of [V16O38Cl]8− cages, with each cage connected to six other neighboring units through [Ni(en)2]2+ bridging groups. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
An Unusual Bonding Situation in a Novel AuI‐Phosphido Complex with a Planar Au3P3 Framework
Authors: Vogel Ulf , Sekar Perumal , Ahlrichs Reinhart , Huniar Uwe , Scheer Manfred 
Published: April 2003

AbstractReaction of the mono‐deprotonated derivative of [{Cp(CO)2Mo}2(μ‐PH2)(μ‐H)] (1) leads to the novel complex [{Cp(CO)2Mo}2(μ‐H){μ3‐P(H)Au(PPh3)}] (2). In contrast the reaction of the analogous Cr derivative [{Cp(CO)2Cr}2(μ‐PH2)(μ‐H)] (1a) leads under identical conditions to a planar Au3P3 cluster [{CpCr(CO)2}6(P3Au3)] (3). Both complexes were completely structurally and spectroscopically characterised. Density functional calculations have shown that 3 is characterised by P−Cr−Au multicentre and Cr‐P multiple bonding. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Self‐Assembly of Supramolecular Structures from Palladium Chloride and Guanidinium Salts of Pyridinecarboxylic Acids − A Dramatic Change on Passing from the para‐ to the meta‐Substituted Acid
Authors: Bacchi Alessia , Chiusoli Gian Paolo , Costa Mirco , Giacobbi Emmanuele 
Published: April 2003

AbstractSupramolecular structures 1 and 2 were obtained in the solid state from the reaction between palladium chloride and guanidinium salts of p‐ and m‐pyridinecarboxylic acid, respectively. The pyridinecarboxylate anions were trans‐coordinated to palladium dichloride through nitrogen, and the carboxylate groups formed hydrogen bonds with guanidinium cations. The present paper describes a remarkable change in the stoichiometry and structural organization of the solid 3 derived from the meta‐substituted acid 2, triggered by the elimination of one guanidine molecule as hydrochloride per molecule of palladium chloride, during crystallization from methanol. The corresponding isonicotinate 1 structure appears to be stable under the same conditions. As shown by the analysis of the crystal structures, the guanidinium nicotinate organic salt 4 turns out to be preorganized to host palladium chloride both in 2 and 3. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Application of Gel‐Phase 195Pt NMR Spectroscopy in a Novel Solid‐Phase Synthesis of a Primary Amine Dichloroplatinum(II) Complex
Authors: Robillard Marc S. , Leith Jason S. , van der Marel Gijs A. , van Boom Jacques H. , Reedijk Jan 
Published: April 2003

AbstractGel‐phase 195Pt NMR spectroscopy of dichloroplatinum peptide complexes attached to a solid support is described. The observed 195Pt chemical shifts of the support‐bound platinum complexes are in good agreement with the solution‐state 195Pt NMR spectra of the soluble and deprotected analogs. This non‐destructive analytical method for on‐resin‐compound analysis was applied in the optimization of the solid‐phase synthesis of the primary amine dichloroplatinum complex 6, which represents a new class of platinum complexes now available via solid‐phase synthetic chemistry. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Metal‐Promoted Cage Rearrangements in the Tricarbollide Series: Conversion of Ligand Derivatives 7‐L‐nido‐7,8,9‐C3B8H10 (L = H3N, tBuH2N, Me2HN) into Neutral 8‐R‐nido‐7,8,9‐C3B8H11 (R = H2N, tBuHN, Me2N) Compounds
Authors: Grüner Bohumír , Štíbr Bohumil , Holub Josef , Císařová Ivana 
Published: April 2003

AbstractDeprotonation of the eleven‐vertex tricarbaborane zwitterions 7‐L‐nido‐7,8,9‐C3B8H10 [1: L = H3N (1a), tBuH2N (1b), Me2HN (1c)], followed by reactions with metal reagents [FeI2, NiCl2, and Ni(C5H5)2] at higher temperatures and in situ acidification, led to the 7 ⇄ 8 rearrangement of the N‐substituted cage carbon atom to yield a series of 8‐amino‐substituted derivatives of nido‐7,8,9‐C3B8H12. These were characterized as 8‐R‐nido‐7,8,9‐C3B8H11 [2: R = H2N (2a), tBuHN (2b), Me2N (2c)]. A possible rearrangement mechanism for their formation has been proposed. Deprotonation of compound 2a with proton sponge [PS = 1,8‐bis(dimethylaminonaphthalene)] generated the [8‐tBuHN‐nido‐7,8,9‐C3B8H10]− (2b−) anion, which can be reprotonated to give the original compound 2b and not the tautomeric zwitterion 8‐tBuH2N‐nido‐7,8,9‐C3B8H10 (3b). All compounds were characterized by high‐field (11B and 1H) NMR and IR spectroscopy, and mass spectrometry. The molecular structures of the neutral carbaborane 2b and its salt PSH+2b−were determined by single‐crystal X‐ray diffraction analyses. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
New Mononuclear Manganese(III) Complexes with Hexadentate (N4O2) Schiff Base Ligands: Synthesis, Crystal Structures, Electrochemistry, and Electron‐Transfer Reactivity towards Hydroxylamine
Authors: Panja Anangamohan , Shaikh Nizamuddin , Gupta Shankareswar , Butcher Ray J. , Banerjee Pradyot 
Published: April 2003

AbstractFour new manganese(III) complexes of hexadentate Schiff base ligand obtained from N,N′‐bis(3‐aminopropyl)ethylenediamine and salicylaldehyde, or salicylaldehyde derivatives having N4O2 donor sets − [Mn(sal‐N‐1,5,8,12)]ClO4 (1), [Mn(5‐Cl‐sal‐N‐1,5,8,12)]ClO4 (2), [Mn(5‐Br‐sal‐N‐1,5,8,12)]ClO4 (3), and [Mn(3‐methoxy‐sal‐N‐1,5,8,12)]ClO4·H2O (4) − have been synthesized and characterized. The crystal structures of 1 and 4 have been determined, and the kinetics of the electron‐transfer reactions between these complexes and hydroxylamine hydrochloride have been followed spectrophotometrically in the 5.5−8.0 pH range. Similar kinetic reactivities of all the complexes towards a particular species of the reductant were noted. Hydrogen‐bonded adduct formation between the reactants prior to electron transfer seems to be a possible reaction pathway, according to analysis of the experimental data. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis, Crystallographic and Spectroscopic Studies of Dimeric CuI Complexes with Schiff‐Base‐Containing Triazole Ligands
Authors: Drabent Krzysztof , Ciunik Zbigniew , Chmielewski Piotr J. 
Published: April 2003

AbstractNew CuI complexes of the Schiff‐base‐containing triazole ligands N‐[(E)‐(4‐chlorophenyl)methylidene]‐4H‐1,2,4‐triazol‐4‐amine (ClPhtrz) and N‐[(E)‐phenylmethylidene]‐4H‐1,2,4‐triazol‐4‐amine (Phtrz) have been synthesised and characterised. Depending on the reaction conditions ClPhtrz forms two different dimeric complexes 1 and 2. X‐ray crystallography revealed that each copper centre exhibits a planar trigonal coordination in 1, while the tetrahedral coordination sphere of the copper centre in 2 is completed by a solvent molecule. In dimeric complex 3 the tetrahedral coordination of the CuI ions is formed by two monodentate and two bidentate (bridging) Phtrz ligands. Complexes 1−3 are unstable and easily lose coordinating and/or solvating acetonitrile molecules giving 4 (from 1 and 2) and 5 (from 3). On the basis of ESI MS and 1H NMR and UV/Vis spectroscopy, it was shown that dimeric complexes 1−5 do not survive upon dissolution and dissociate rapidly forming mainly a 1:2 monomeric complex, along with a minor 1:1 complex. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
The Electronic Absorption Characteristics of Mixed Phthalocyaninato Porphyrinato Rare Earth(III) Triple‐Deckers M2(TPyP)2(Pc)
Authors: Sun Xuan , Cui Xuegui , Arnold Dennis P. , Choi Michael T. M. , Ng Dennis K. P. , Jiang Jianzhuang 
Published: April 2003

AbstractMixed phthalocyaninato tetrakis(4‐pyridyl)porphyrinato rare earth triple‐decker complexes M2(TPyP)2(Pc) [M = La (1), Eu (2)] have been prepared by condensation between M(TPyP)acac generated in situ and M(Pc)2. Their symmetrical structure (TPyP)M(Pc)M(TPyP) was verified by 1H NMR (1D and 2D) spectra in CDCl3 solutions. The electronic absorption spectra of these two compounds were recorded in the UV/Vis and near‐IR region. A weak absorption in the near‐IR region at 860 and 942 nm for 1 and 2, respectively, was observed as the lowest energy band and is attributed to the electronic transition from HOMO to LUMO for these mono(phthalocyaninato) bis(porphyrinato) rare earth complexes. Their electrochemical properties were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Analysis of the relationship between the optical and redox properties of M2(TPyP)2(Pc) reveals that the HOMO and LUMO of M2(TPyP)2(Pc) have both porphyrin and phthalocyanine character. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Structures of Carbonato and Bicarbonato Complexes of Bis(1,10‐phenanthroline)Zinc(II): Experiment and Theory
Authors: Erras‐Hanauer Hans , Mao Zong‐Wan , Liehr Günter , Clark Timothy , van Eldik Rudi 
Published: April 2003

AbstractWe report experimental and theoretical studies on the structure and properties of carbonato and bicarbonato complexes of bis(1,10‐phenanthroline)zinc(II). The complex [Zn(phen)2O2CO] has been synthesized and DFT calculations have been performed based upon its X‐ray structure. The carbonate ligand coordinates in a bidentate binding mode to the metal centre with Zn−O distances of 2.130 and 2.092 Å in the X‐ray structure and 2.027 Å for both distances in the calculated gas‐phase structure. Because of the fundamental role of (bicarbonato)ZnII complexes, especially in different carbonic anhydrases, the structures and properties of the experimentally unknown bicarbonato complexes of this kind were investigated using DFT with different basis sets up to the Ahlrichs triple zeta basis set with additional polarization functions. The bidentate bicarbonato complex [Zn(phen)2O2C(OH)]+ was found to be about 8.2 kcal·mol−1 (SHAsvp), 6.4 kcal·mol−1 (Ahlrichs triple zeta with polarization functions) and 3.5 kcal·mol−1 (Ahlrichs triple zeta) more stable than the quasi‐monodentate bicarbonato complex [Zn(phen)2O(OH)CO]+. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Ethylene Polymerization by Self‐Immobilized Neutral Nickel Catalysts Bearing Allyl Groups
Authors: Zhang Dao , Jin Guo‐Xin , Hu Ning‐Hai 
Published: April 2003

Abstract[Ni(Ph)(PPh3)(N,O)] complexes containing phenylimino‐phenolato ligands (N,O) (1: N,O = A; 2: N,O = B; 3: N,O = C; 4: N,O = D; 5: N,O = E) have been synthesized and characterized. The molecular structure of 4 was determined by single‐crystal X‐ray analysis. Complexes 2−5 bearing allyl groups have been investigated as self‐immobilized catalysts for ethylene polymerization without the use of co‐catalysts. The high ethylene polymerization activities of ca. 105 g·PE mol−1 Ni·h−1 and high molecular weight (Mw ≈︁ 105) of polyethylene could be accomplished by changing the ligand structures and reaction conditions. The self‐immobilization of catalysts brings about a dramatic increase in the catalytic activities of ethylene polymerization. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Intercalation of Amino Alcohols into α‐Zr(HPO4)2·H2O
Authors: Beneš Ludvík , Melánová Klára , Zima Vítězslav , Patrono Pasquale , Galli Paola 
Published: April 2003

AbstractThe formation of phases during the intercalation of amino alcohols (2‐aminoethanol, 3‐aminopropanol, 4‐aminobutanol, 5‐aminopentanol, and 6‐aminohexanol) into α‐Zr(HPO4)2·H2O was studied. The existence of three phases with general formula α‐Zr(HPO4)2·xNH2(CH2)nOH·zH2O (x = 0.5, 1, 2; n = 2−6; z = 0.2−1.2) depends on the molar ratio of the starting compounds in the reaction mixture. The compounds α‐Zr(HPO4)2·2NH2(CH2)nOH·1.2H2O (n = 5 and 6) lose water and one molecule of amino alcohol upon heating to about 200 °C, as observed by thermal X‐ray diffraction measurements. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Cover Picture: Combining Magnets and Dielectrics: Crystal Chemistry in the BaO−Fe2O3−TiO2 System (Eur. J. Inorg. Chem. 8/2003)
Authors: Siegrist Theo , Vanderah Terrell A. 
Published: April 2003

AbstractThe cover picture shows two views of Ba5Fe4Ti10O31 type structure. Barium atoms are shown as yellow spheres, iron tetrahedra are depicted in red, iron trigonal bipyramids in gold, and titanium octahedra in blue. On the left side is a full unit cell stack of 18 layers, on the right side, the unique 9‐layer repeat unit is shown. Details are discussed in the Microreview by T. Siegrist and T. A. Vanderah on p. 1483 ff.
A Study of the Equilibrium and Kinetics of Urea Binding by a Biomimetic Dinickel(II) Complex
Authors: Kryatov Sergey V. , Rybak‐Akimova Elena V. , Meyer Franc , Pritzkow Hans 
Published: April 2003

AbstractThe equilibrium and kinetics of urea binding by model dinickel complexes have been studied, which is relevant to the activity of the urease enzyme. The pyrazolate‐based, O2H3‐bridged dinuclear nickel(II) complex [LNi2(OH)(H2O)]2+ (1) binds urea reversibly in organic solvents with the formation of an N,O‐bridged urea anion complex [LNi2[OC(NH2)NH)]2+ (2) and two water molecules. The equilibrium constant has been measured as 4.3(4) in acetone, 2.7(5) in acetonitrile, and 3(1) in methanol at 25 °C. Upon dissolving 1 in anhydrous methanol, the O2H3 bridge is substituted for an O2Me2H bridge to give [LNi2(OMe)(MeOH)]2+ (4),which has been crystallized as 4·(ClO4)2 and characterized by X‐ray diffraction. Both NiII ions in 4 are five‐coordinate with geometries intermediate between square‐pyramidal and trigonal‐bipyramidal. The H atom in the Me2O2H bridging unit is located in an asymmetric position. The exchange of water and methanol ligands in complexes 1 and 4 is very fast in solution at 25 °C (kobsd. > 103 s−1). Binding of urea by complexes 1 and 4 are slower reactions (kobsd. ≈︁ 10−1 to 101 s−1 under the concentration conditions used) and can be monitored by stopped‐flow techniques. Detailed kinetic studies indicate that binding of urea is a multi‐step process. Steady‐state intermediates of the tentative formula [LNi2(OR)(urea)n]2+ (n = 1, 2) are formed in fast preequilibrium with the starting complexes 1 (R = H) and 4 (H = Me), respectively. The bidentate N,O‐coordination and deprotonation of an O‐bound urea ligand constitute the overall rate‐limiting step. The kinetic data suggest that both mono‐ and bis(urea) complexes participate in the formation of the chelate 2, and that the latter are substantially more reactive. The bis(urea) pathway was unexpected because only one urea molecule is incorporated into the final product 2. Reactive intermediates [LNi2(OH)(urea)n]2+ are close analogs of the reactive intermediate of urease, which also has the hydroxide and urea ligands bound at a dinickel core. However, the reactivities of the intermediates are different. The hydroxide ligand in our model complex acts as a base towards urea, and the urea anion complex 2 is formed. In urease, the hydroxide ligand attacks urea as a nucleophile leading to the hydrolysis of urea. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis and Characterization of New Transplatinum Complexes Containing Phosphane Groups − Cytotoxic Studies in Cisplatin‐Resistant Cells
Authors: Ramos‐Lima Francisco J. , Quiroga Adoración G. , Pérez José M. , Font‐Bardía Mercé , Solans Xavier , Navarro‐Ranninger Carmen 
Published: April 2003

AbstractIn this paper we report the synthesis and characterization of novel trans platinum(II) complexes of general formula trans‐[PtCl2(L)(PPh3)], where L is NH2CH(CH3)CH2CH3 (complex 1), (R)‐NH2CH(CH3)CH2CH3 (complex 2), (S)‐NH2CH(CH3)CH2CH3 (complex 3) and NH2CH(CH3)2 (complex 4). The new complexes contain phosphane ligands trans to the amine group. X‐ray crystal structure determinations of complexes 1 and 3 confirmed their trans configurations. The cytotoxic activity of these complexes have been evaluated and compared with the activity of trans platinum complexes already viewed as potential drugs. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)