bluuebunny/crossref_metadata_2025 huggingface dataset:
A guideline for the design of sinusoidal excitation equipment
Authors: Okada Yoshimoto , Ikeda Shinji , Kitamura Kazuaki
Published: February 2004

In recent years, sinusoidal excitation equipment, that is, a two‐phase induction motor fed by an AC and DC voltage source, has been employed in angular accelerating calibration of the angular accelerometer, the measuring device for the moment of inertia, cleaning and polishing device, and so on, as an exciter. Generally, the excitation equipment is required to have larger alternating torque. Previously, we have derived a practical equation to calculate the alternating current torque of excitation equipment. In this paper, first, for the sinusoidal excitation equipment—two‐phase induction motor fed by AC and DC voltage source—the relation among the equipment circuit parameters and the alternating torque characteristics are investigated numerically. Then, the influence of equivalent circuit parameters on the alternating torque characteristics and its tendencies are clarified. Second, a guideline for the excitation equipment design that can generate larger alternating torque are presented using the equivalent circuit parameters. Last, in order to verify the validity of the new strategy, the trial excitation equipment which is designed by various redesign conditions is compared with previous excitation equipment. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(1): 70–77, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10237
The development of generator modeling techniques for multimode oscillations and study of generator H ∞ control design method for robust control
Authors: Michigami Tsutomu , Nara Kazunori , Omata Hitoshi
Published: February 2004

Modern electric power systems of Japan are characterized by high density, wide area coverage, and a complicated structure. Multimode oscillations occur in the generators connected to the systems. These oscillations represent a combination of high‐ and low‐frequency modes that occur between individual power systems and oscillations of other types, such as the SSR and cross‐compound machine oscillations, which are characteristic mode oscillations of generators. In this paper, we first construct a real model of the generator that realizes the multimode oscillations. Next, model reduction of this real model is carried out, and a design model to be used for the control design is constructed. The H ∞ control design based on the modern control theory is presented by using this design model, which implements the damping of power system oscillations and robust stabilization of other multiple modes. In conclusion, we confirm that the target parameters of the control design have been achieved. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(1): 42–52, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10253
Stabilization control for multimachine system using decentralized H∞ excitation controller realizing terminal voltage control and damping control
Authors: Senjyu Tomonobu , Morishima Yoshiteru , Yamashita Takahiro , Uezato Katsumi , Fujita Hideki
Published: February 2004

In this paper, to achieve both damping of power system oscillation and terminal voltage control simultaneously on a multimachine power system, we propose a decentralized H∞ excitation controller. In the proposed method, H∞ control via the Normalized Coprime Factorization approach is used to achieve the proposed design idea. By the Normalized Coprime Factorization approach, the weighting function in H∞ control design is simplified, and output feedback controllers that take into account the realities and constraints of the power systems are designed. The proposed controller is subjected to model reduction of H∞ controllers, and is transformed to a discrete system to perform digital control by computer systems in consideration of application to a real system. We verify that the proposed excitation controller can achieve both damping of power system oscillation and terminal voltage control by computer simulations of a multimachine power system. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(1): 33–41, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10254
A study on an active noise control system using an adaptive exponential filter
Authors: Kobayashi Masaki , Itoh Yoshio
Published: February 2004

Active noise control systems that have been studied previously require a replica of the cancellation path to obtain the updating weight values, because the signals for the operation cannot be observed. In this paper we propose a structure and an adaptive algorithm for the active noise control system using an adaptive exponential filter that does not require any replica. The adaptive algorithm is based on the steepest descent method that can be easily realized and the updating weight value of the adaptive exponential filter is the correlation of the observable output signal of the adaptive system and the estimation error. The other adaptive filters are composed of the linear transversal system. It is proven that the transfer function after converging completely corresponds to the transfer function of the noise and the cancellation path under a certain condition. Finally, the convergence performance of the estimation accuracy and the tracking performance with respect to rapid changes of the noise and the cancellation paths are verified by computer simulation. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(1): 53–59, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10256
The influence of wave front duration of impulse voltage on creeping discharges along aerial insulated wire
Authors: Nishi Toshiyuki , Hanaoka Ryoichi , Takata Shinzo , Miyamoto Toshio
Published: February 2004

In high‐voltage aerial distribution systems, creeping discharges progress along the cable surface from the free end of the binding wire when overvoltages caused by a lightning surge have invaded the central line of an insulated cable. Consequently, various accidents such as punch‐through breakdown, melting, or snapping of a cable, often occur at these systems. In our previous studies, it has been clarified that the lengths and aspects of creeping discharges under a 1.2/50 µ s impulse voltage condition can be markedly affected by changes in the electric field strength on the cable surface. However, lightning impulse surges which may invade the central line of a cable have various wave front durations. This will further complicate creeping discharge phenomena due to lightning.

In this paper, we report the influence of the wave front duration on both the lengths and the aspects of the creeping discharges which progress on the cable on application of lightning impulse voltages. It has been shown that the behavior of negative creeping discharges reveals pronounced changes in response to the duration of the wave front of the applied voltage. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(2): 30–38, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10263
Detection of nitrogen metastable molecules by using the threshold ionization mass spectrometry
Authors: Matsuda Satoshi , Shimosato Hirotsugu , Yumoto Motoshige , Sakai Takao
Published: February 2004

The N2(A3Σu+) state has a rather long radiation lifetime, and its electron energy is high. Accordingly, it is expected that chemical reactions in the space where many metastable molecules are accumulated will be accelerated. Therefore, it is important to detect metastable molecules and to evaluate the number density of the molecules. With a view to detecting the N2(A3Σu+) state in nitrogen plasma, the authors used threshold ionization mass spectrometry. For that purpose a quadrupole mass spectrometer (QMS) was modified to control its electron energy for ionization. Magnitude of the QMS signal was compared with the ionization cross section of the N2(A3Σu+) state brought about by electron collision, and its number density was estimated. Using the method, it was recognized that the density of N2(A3Σu+) increased in proportion to the discharge current. It was likewise recognized that the density of the current was rapidly decreased in the vicinity of the glass wall. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(1): 17–24, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10270
Effects of magnetic field on the carrier density distribution of semiconductor power device operated in pulsed power conditions
Authors: Matsumoto Yasuhiro , Aoki Takashi , Tamura Yukihiko , Ibuka Shinji , Yasuoka Koichi , Ishii Shozo , Yura Masashi , Shimizu Naohiro
Published: February 2004

Turn‐on characteristics of semiconductor power devices are evaluated under external magnetic field to study the effects of external magnetic field generated in a pulsed power circuit. Two pin diodes that have a basic structure of power devices are connected in parallel and driven by a pulsed voltage source. It was found the magnetic field applied to one diode in the perpendicular direction of current‐flow changed the current balance between the diodes. Besides the on‐resistance of a diode was increased under external magnetic field. The carrier‐density distribution inside of the diodes was measured by using a free carrier absorption method. The data show that the carrier‐density distribution changes from nearly the uniform one to the one‐sided one. It can be concluded that the effects of magnetic‐field have to be considered for the evaluation of switching characteristic in pulsed power operations. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(1): 10–16, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10271
Estimation of the electric parameters of thin electromagnetic shielding materials
Authors: Nagano Isamu , Yoshimura Yoshiyuki , Yagitani Satoshi , Yokomoto Hiroaki , Tosaka Toshihide , Nakayabu Toshihiro
Published: February 2004

It is important to know the electric parameters of the shielding material for numerical analysis. The purpose of this report is to estimate electric parameters of thin shielding materials. The electromagnetic field in the vicinity of a horizontal multilayered material with a magnetic dipole source is calculated numerically by a Sommerfeld integral. On the basis of this calculation, we develop a “shielding box” for measuring the shielding effectiveness (SE) with little error. We compare the magnetic SE measured with the shielding box with that obtained by calculation to evaluate this method. Because calculation results are in good agreement with measurement results, we confirm that we can measure magnetic SE of thin shielding materials with this system. Next, we propose a method to estimate unknown electric parameters of shielding materials by using the SE measurement system and the numerical calculation. The electric parameters are derived by iterating numerical calculations to fit the experimental results within 1‐dB error. We estimated the electric parameters of A1 (aluminum) material. Fitted results are in good agreement with the well‐known values, demonstrating the validity of the developed method. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(1): 1–9, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10273
Midterm stability evaluation of wide‐area power system using synchronized phasor measurements
Authors: Ota Yutaka , Ukai Hiroyuki , Nakamura Koichi , Fujita Hideki
Published: February 2004

In recent years, the PMU (Phasor Measurement Unit) has received a great deal of attention as a synchronized measurement system of power systems. Synchronized phasor angles obtained by the PMU provide valuable information for evaluating the stability of a bulk power system. The aspect of instability phenomena during midterm tends to be more complicated, and the stability analysis using the synchronized phasor measurements is effective in order to keep a complicated power system stable. This paper proposes a midterm stability evaluation method for the wide‐area power system using synchronized phasor measurements. By clustering the power system to some coherent groups, step‐out is predicted on the basis of an aggregated two‐machine equivalent power system. The midterm stability of a longitudinal power system model of Japan's 60‐Hz systems constructed by a hybrid‐type power system simulator is practically evaluated using the proposed method. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(1): 25–32, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10274
Loss calculation of induction motors considering harmonic electromagnetic field in stator and rotor
Authors: Yamazaki Katsumi
Published: February 2004

A method of loss calculation for induction motors is proposed. The combined 3D–2D time‐stepping finite element analysis is carried out to obtain the copper loss and the time variation of the magnetic field in the motor. The iron loss is calculated approximately considering the time variation of the magnetic field direction and the minor hysteresis loops caused by the time‐harmonic fields using practical computer resources. The proposed method is applied to four types of induction motors, which are the solid rotor induction motors with/without slot and the cage induction motors with/without skew. The measured and the calculated total losses and the iron losses agree well in all cases. The differences of the loss distributions of each motor are also compared and investigated. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(2): 63–73, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10305
Architecture for high‐speed evolutionary computation
Authors: Yoshikawa Masaya , Imai Tetsuya , Kodama Tomoyuki , Yamauchi Hiroori , Terai Hidekazu
Published: February 2004

Genetic algorithms (GA) are widely known as a general‐purpose optimization method, which can provide suboptimum solutions for various optimization problems by means of modeling genetic evolutionary processes of creatures. Several essential difficulties exist in GA, however, with regard to large amount of computation time and proper adjustment of many GA parameters. In order to overcome the difficulties of GA, this paper describes the architecture for a high‐speed evolutionary computation, which is optimized hierarchic pipelines to take generation models into consideration and can be flexible genetic operations corresponding to a given problem. Simulation results evaluating the proposed architecture are shown to achieve a speed 193 times faster on average compared to software processing. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(2): 39–52, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10308
An investigation of surge propagation characteristics on an 1100‐kV transmission line
Authors: Ametani Akihiro , Adachi Kazutoshi , Narita Tomomi
Published: February 2004

This paper investigates the surge propagation characteristics of an 1100‐kV transmission line based on field test results and EMTP simulations. The EMTP simulations shows that the arc horn voltage is almost the same as the phase‐wire voltage to earth, and thus the measured arc horn voltage can be regarded as the phase‐to‐earth voltage. The surge‐wave deformation after a distance greater than 2 km measured in the field test is analytically explained as due to separation of modal traveling waves, the earth‐return and the aerial modes, because the travel times of the two modes become noticeably different. A distinctive feature of the 1100‐kV line is its very small attenuation, about half that on a 500‐kV transmission line. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(2): 22–29, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10316
A high‐speed reclosing method to improve the stability in a power system
Authors: Yukita Kazuto , Kojima Daisuke , Yamada Hiroshi , Mizuno Katsunori , Goto Yasuyuki , Ichiyanagi Katsuhiro
Published: February 2004

This paper proposes a high‐speed reclosing operating method to improve the stability in a power system. The proposed method calculates the reclosing time, taking a standard case in which the reclosing is not done using the generator phase angle δ, and the angular velocity ω, and the field system voltage ed′. Also, the execution of reclosing time is calculated, while taking into consideration the acceleration/deceleration energy of the generator during a fault. It can be expected that δ is suppressed by this optimum reclosing operation. Therefore, the system stability can be expected to improve by carrying out high‐speed reclosing when a fault occurs. At present, it has been set at a value which seems to be optimal considering various problems in the reclosing time. However, in those methods, the system stability improvement effect cannot be expected. It was demonstrated that the high‐speed reclosing method serves to depress δ in the computer simulation. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(2): 13–21, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10317
A study of collaborative operation between a new energy type dispersed power supply system and SMES by modified Euler type moving average prediction model
Authors: Monai Toshiharu , Takano Ichiro , Nishikawa Hisao , Sawada Yoshio
Published: February 2004

In this paper, the modified Euler type Moving Average Prediction (EMAP) model is proposed in order to operate a dispersed power supply system using new energy in autonomous mode. Furthermore, the EMAP model is used to operate a new type of dispersed power supply system consisting of a large‐scale photovoltaic system (PV), a fuel cell (FC), and a small‐scale superconducting magnetic energy storage system (SMES). This distributed power supply system can meet the multiple‐quality electric power requirements of customers, and ensures voltage stability and UPS (Uninterruptible Power Supply) functions as well. Each subsystem of this distributed power supply contributes to the above‐mentioned system performance with its own excellent characteristics. Moreover, the response characteristics of this system are confirmed by simulation with PSIM software, and, using collaborative operation under the EMAP model, the required capacity of SMES to compensate the fluctuation of both PV output and load demand is examined by simulation, using MATLAB/Simulink. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(2): 1–12, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10318
A basic study of defect inspection methods for ASIC manufacturing line (Second report: Inspection parameter dependence on yield and cleaning cycle)
Authors: Sakurai Koichi , Fujii Susumu , Kaihara Toshiya
Published: February 2004

The results of strict defect control include both the enhancement of manufacturing yield and increased delivery delay due to a drop in the machine operation rate. Therefore, defect inspection methods must be optimized for this trade‐off, especially for ASIC manufacturing. In the first paper, we proposed a new manufacturing model which treats not only inspection and the yield model, but also the workflow model. In this paper, we formulate the inspection parameter dependence on the manufacturing yield and the machine cleaning cycle, which may affect delivery time. By using the resulting formulas, factory engineers can obtain practical information for inspection parameter optimization. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(2): 53–62, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10328
Direct Hydride/Silyl Exchange — Synthesis and X‐ray Study of the Bis(silyl) Complex [Cp2NbH(SiCl3)2]
Authors: Dorogov Konstantin Yu. , Churakov Andrei V. , Kuzmina Lyudmila G. , Howard Judith A. K. , Nikonov Georgii I.
Published: February 2004

Niobocene trihydride reacts directly with the chlorosilanes SiCl2R′R′′ (R′, R′′ = Me, Ph) and SiCl3Me to give the dihydridomonosilyl derivatives [Cp2Nb(H)2(SiClnR3−n)] (n = 1, 2), whereas the analogous reaction with SiCl4 affords [Cp2Nb(H)2(SiCl3)] and the bis(silyl) complex [Cp2NbH(SiCl3)2], whose X‐ray structure was determined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Tuning the Catalase Activity of Dinuclear Manganese Complexes by Utilizing Different Substituted Tripodal Ligands
Authors: Reddig Nicole , Pursche Daniel , Kloskowski Michael , Slinn Caroline , Baldeau Sascha M. , Rompel Annette
Published: February 2004

A series of five new dinuclear manganese(II/II) compounds with derivatives of 2‐{[bis(pyridin‐2‐ylmethyl)amino]methyl}phenol (HL1) were synthesized and structurally characterized. All complexes crystallize in monoclinic space groups and exhibit Mn···Mn separations in the range of 3.392(8)−3.493(2) Å caused by bis(µ‐phenoxo) bridging modes. The derivatives of HL1 contain either electron‐donating or ‐withdrawing substituents. A correlation between the electronic character of the different ring substituents, the redox potentials of the dinuclear transition metal complexes and the catalase activity has been revealed. In analogy to manganese catalase, all complexes show saturation kinetics at high substrate concentration. The investigated catalase activity places the compounds in the upper range of functional catalase mimics. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A Bis(diazadiene) Adduct of MoCl2: Mononuclear, Octahedral, Undistorted and Diamagnetic
Authors: Stoffelbach François , Rebière Bertrand , Poli Rinaldo
Published: February 2004

The complex [MoCl2(iPr2dad)2] (iPr2dad = iPrN=CH−CH=N−iPr) is obtained in one step by reduction of [MoCl3(THF)3] in the presence of iPr2dad. The X‐ray structure reveals a relatively undistorted octahedral coordination geometry with a relative cis configuration and points to a more appropriate description of the ligands as enediamides. The NMR investigation is in agreement with the same cis structure in solution and underlines the diamagnetism of the compound, at odds with previously reported very similar complexes. A bulk magnetic susceptibility measurement further confirms the compound’s diamagnetism. No equilibrium with a dinuclear, metal‐metal bonded species is apparent from the solution studies. A DFT calculation on the real molecule and on two R2dad model systems with R = Ph and 4‐HOC6H4 reveals how the ligand periphery delicately controls the magnetic and structural properties of this system. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Template Synthesis, Crystal Structure and Luminescent Properties of Neutral N4O3 Tripodal LnIIIL Complexes (LnIII = La3+, Eu3+, Gd3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+ or Lu3+; H3L = Tris{[3′‐(2′′‐pyridyl)‐5′‐tert‐butyl‐2′‐hydroxybenzylidene‐2‐imino]ethyl}amine)
Authors: Wong Wai‐Kwok , Liang Hongze , Guo Jianping , Wong Wai‐Yeung , Lo Wing‐Kit , Li King‐Fai , Cheah Kok‐Wai , Zhou Zhongyuan , Wong Wing‐Tak
Published: February 2004

In the presence of Ln3+ (Ln = La, Eu, Gd, Tb, Dy, Ho, Er, Tm or Lu), tris(2‐aminoethyl)amine condensed with three equivalents of 3‐(2′‐pyridyl)‐5‐tert‐butyl‐2‐hydroxybenzaldehyde in methanol to give the neutral Schiff‐base complex LnIIIL (Ln = La 1, Eu 2, Gd 3, Tb 4, Dy 5, Ho 6, Er 7, Tm 8 and Lu 9; H3L = tris{[3′‐(2′′‐pyridyl)‐5′‐tert‐butyl‐2′‐hydroxybenzylidene‐2‐imino]ethyl}amine). The structures of compounds 4−7 were determined by X‐ray crystallography. The crystal structure analyses revealed that the Schiff base behaves as a tri‐deprotonated heptadentate ligand encapsulating the lanthanide metal ion within the N4O3 cavity, with all the pyridyl groups being pendant. Solution spectroscopic data suggest that the LnIIIL complexes remain intact in methanol and exist as nine‐coordinate non‐electrolytes with the lanthanide metal ions coordinated to the N4O3 cavity of the tripodal Schiff base and two solvent molecules. The solution photoluminescent properties of these lanthanide Schiff‐base complexes were also examined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Kinetic Studies of the Oxidative Addition and Transmetallation Steps Involved in the Cross‐Coupling of Alkynyl Stannanes with Aryl Iodides Catalysed by η2‐(Dimethyl fumarate)(iminophosphane)palladium(0) Complexes
Authors: Crociani Bruno , Antonaroli Simonetta , Canovese Luciano , Uguagliati Paolo , Visentin Fabiano
Published: February 2004

The complexes [Pd(η2‐dmfu)(P−N)] {dmfu = dimethyl fumarate; P−N = 2‐(PPh2)C6H4−1‐CH=NR, R = C6H4OMe‐4 (1a), CHMe2 (2a), C6H3Me2‐2,6 (3a), C6H3(CHMe2)2‐2,6 (4a)} undergo dynamic processes in solution which consist of a P−N ligand site exchange through initial rupture of the Pd−N bond at lower energy and an olefin dissociation‐association at higher energy. According to equilibrium constant values for olefin replacement, the complex [Pd(η2‐fn)(P−N)] (fn = fumaronitrile, 1b) has a greater thermodynamic stability than its dmfu analogue 1a. The kinetics of the oxidative addition of ArI (Ar = C6H4CF3‐4) to 1a and 2a lead to the products [PdI(Ar)(P−N)] (1c, 2c) and obey the rate law, kobs = k1A + k2A[ArI]. The k1A step involves oxidative addition to a reactive species [Pd(solvent)(P−N)] formed from dmfu dissociation. The k2A step is better interpreted in terms of oxidative addition to a species [Pd(η2‐dmfu)(solvent)(κ1‐P−N)] formed in a pre‐equilibrium step from Pd−N bond breaking. The complexes 1c and 2c react with PhC≡CSnBu3 in the presence of an activated olefin (ol = dmfu, fn) to yield the palladium(0) derivatives [Pd(η2‐ol)(P−N)] along with ISnBu3 and PhC≡CAr. The kinetics of the transmetallation step, which is rate‐determining for the overall reaction, obey the rate law: kobs = k2T[PhC≡CSnBu3]. The k2T values are markedly enhanced in more polar solvents such as CH3CN and DMF. The solvent effect and the activation parameters suggest an associative SE2 mechanism with substantial charge separation in the transition state. The kinetic data of the above reactions in various solvents indicate that, for the cross‐coupling of PhC≡CSnBu3 with ArI catalysed by 1a or 2a, the rate‐determining step is represented by the oxidative addition and that CH3CN is the solvent in which the highest rates are observed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis, Structure and Hydrolytic Properties of a Family of New Zn Complexes Containing Hexaazamacrocyclic Ligands
Authors: Costas Miquel , Anda Carmen , Llobet Antoni , Parella Teodor , Stoeckli Evans Helen , Pinilla Elena
Published: February 2004

The synthesis, structure and spectroscopic properties of a family of Zn complexes containing a dinucleating hexaazamacrocyclic ligand (L) and anionic ligands (X) of general formula [Zn2(X)4−n(L)]n+ (1−8; L = H2p, H3p, Me2p, Me2m, Me3p, Me3m; X = Cl, n = 0; X = NO3, n = 2) have been investigated. The solid‐state structural characterisation has been performed by means of X‐ray diffraction analysis for complexes 3, 5, 7·1/3CH2Cl2 and 8. The Zn complexes 5, 7·1/3CH2Cl2 and 8 containing chloride ligands present a distorted N2Cl2 tetrahedral coordination with two non‐coordinated N atoms of the macrocyclic ligand. On the other hand, complex 3, which contains nitrate ligands, displays an N3O2 pentacoordination with all the N atoms of the macrocyclic ligand bonded to the metal centres. The different factors governing the relative Zn−Zn disposition are discussed. NMR spectroscopy in solution reveals the presence of fluxional behaviour and a completely different structural arrangement than in the solid state. In particular, evidence for the formation and breaking of Zn−N bonds involving all the macrocyclic ligand aminic N atoms is obtained for the chloride complexes 2 and 4−8. Finally, complexes 1, 3, 5 and 7 hydrolyse p‐nitrophenyl acetate (NA) with second‐order rate constants ranging from 0.045 to 0.193 M−1s−1, thus manifesting the influence of the ligands over the hydrolytic activity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis, Structures and Reactions of Novel 9,10‐Dihydro‐9,10‐distannaanthracenes
Authors: Saito Masaichi , Henzan Natsumi , Nitta Minehiko , Yoshioka Michikazu
Published: February 2004

A method for the synthesis of 9,10‐dihydro‐9,10‐distannaanthracenes has been improved and applied to the synthesis of novel unsymmetrical 9,10‐dihydro‐9,10‐distannaanthracenes. The first 9,9,10,10‐tetrahalo‐9,10‐dihydro‐9,10‐distannaanthracenes were successfully synthesized by halogenation of 9,9,10,10‐tetrakis(p‐methoxyphenyl)‐9,10‐dihydro‐9,10‐distannaanthracene. The structures of the newly obtained 9,10‐dihydro‐9,10‐distannaanthracenes were determined by X‐ray analysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
The Dynamic Status Quo of Polyhedral Silsesquioxane Coordination Chemistry
Authors: Hanssen Rob W. J. M. , van Santen Rutger A. , Abbenhuis Hendrikus C. L.
Published: February 2004

The chemistry of polyhedral oligomeric silsesquioxanes (POSS) has taken a tremendous leap over the past decade. New synthetic approaches have been developed, and new complexes based on elements throughout the periodic table have been synthesized and applied in catalytic processes such as alkene epoxidation, Oppenauer oxidation, alkene polymerization, Diels−Alders reactions and alkene metathesis. The use of silsesquioxane ligands as models for silica surface has provided an intimate knowledge of the reactions on the surface of this much‐used support. New methods have been developed to incorporate silsesquioxanes into new materials. Encapsulation in siloxane polymers has provided precision supports for catalysts and controlled calcination has produced materials with well‐defined metal oxide particles. This paper reviews the history and the latest developments of silsesquioxane chemistry. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A Comparison of the Reactivity of Chloroalkanes and Chlorosilanes towards Activated PtII Complexes by DFT Calculations
Authors: Sturmayr Dietmar , Schubert Ulrich
Published: February 2004

The pathways of the C−Cl bond activation of CCl4 and CH3Cl by the 14‐electron PtII complexes [PtMe2(PH3)] or the corresponding reactions of SiCl4 and SiH3Cl with [PtMe(SiH3)(PH3)] were investigated by DFT calculations. The complexes [Pt(EH3)Me(PH3)] (E = C, Si) are models for [Pt(EH3)Me{(κ2‐P,N)‐Ph2PCH2CH2NMe2}], with hemilabile P,N chelating ligands, used in practical experiments. While the reaction of [Pt(EH3)Me(PH3)] with ECl4 results in an EH3/ECl3 exchange, reaction of [Pt(EH3)Me(PH3)] with EH3Cl results in the elimination of E2H6. Both reactions proceed via a five‐coordinate PtIV intermediate. The elimination of Si2H6 is endothermic. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Structural Snapshots of a Dynamic Coordination Sphere in Model Complexes for Catechol 1,2‐Dioxygenases
Authors: Merkel Michael , Schnieders David , Baldeau Sascha M. , Krebs Bernt
Published: February 2004

A series of mononuclear iron(III) complexes as models for intradiol cleaving catechol dioxygenases has been synthesized. In all six compounds, the iron(III) core is coordinated by the ligand [(6‐bromo‐2‐pyridyl)methyl]bis[(2‐pyridyl)methyl]amine (brtpa) which mimics the endogenous ligands of this enzyme class and their dynamic behavior. Its steric hindrance pushes the α‐substituted pyridine arm of the ligand away from the coordination site in the presence of nucleophiles. This effect turns the iron‐brtpa system into an excellent model system for the first step in the reaction mechanism of intradiol cleaving chatechol dioxygenases. The proton acceptor abilities of the bromopyridyl arm are underlined by a hydrogen bond to a coordinated methanol molecule in one of the new compounds and by base dependent kinetic investigations. The presented model system is an effective catalyst that requires between 0.5 and 1.0 fewer equivalents of external base than most other complexes due to the integration of an internal base. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Dihydrobis(pyrazolyl)borate Alkylidyne Complexes of Tungsten
Authors: Hill Anthony F. , Malget John M. , White Andrew J. P. , Williams David J.
Published: February 2004

[W(≡CR)Br(CO)2(NC5H4Me‐4)2] (R = C6H3Me2‐2,6 1a, C6H2Me3‐2,4,6 1b) react with K[H2B(pz)2] (pz = pyrazol‐1yl) to provide two interconverting isomers of [W(≡CR)(CO)2(NC5H4Me‐4){H2B(pz)2}] (2), one isomer having been structurally characterised for R = C6H3Me2‐2,6 (2a). The reactions of [W(≡CR)Br(CO)2(CNR′)2] (5: R′ = C6H3Me2‐2,6, CNMe3) with K[H2B(pz)2] or of [W(≡CR)Br(CO)2(NC5H4Me‐4){H2B(pz)2}] (2) with isocyanides are more complex due to the facile formation of unstable ketenyl derivatives. In the absence of light, the reaction of [W(≡CR)Br(CO)2(CNR′)2] (5) with K[H2B(pz)2] provides [W(≡CR)(CO)2(CNR′){H2B(pz)2}] (3) in moderate yield, similar yields were obtained from [W(≡CR)(CO)2(NC5H4Me‐4){H2B(pz)2}] (2) and CNR′. Under mild photolytic conditions both combinations provide primarily the thermally unstable ketenyl complex [W(η2‐OCCR)(CO)(CNR′)2{H2B(pz)2}] (4). The picoline ligand in [W(≡CR)Br(CO)2(NC5H4Me‐4){H2B(pz)2}] (2) is readily replaced by PMe2Ph to provide [W(≡CR)(CO)2(PMe2Ph){H2B(pz)2}] (structurally characterised for R = C6H3Me2‐2,6 6a). The reaction of either [W(≡CR)(CO)2(PMe2Ph){H2B(pz)2}] (6) or [W(≡CR)(CO)2(NC5H4Me‐4){H2B(pz)2}] (R = C6H2Me3‐2,4,6 2b) with excess PMe2Ph provides [W(≡CR)(CO)(PMe2Ph)2{H2B(pz)2}] (7). This complex is also obtained from K[H2B(pz)2] and [W(≡CR)Br(CO)(PMe2Ph)3] (8), the latter arising from the reaction of [W(≡CR)Br(CO)2(NC5H4Me‐4)2] (1b) with PMe2Ph. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
New Bulky Bis(amino)cyclodiphosph(III)azanes and Their Titanium(IV) Complexes: Synthesis, Structures and Ethene Polymerization Studies
Authors: Axenov Kirill V. , Kotov Vasily V. , Klinga Martti , Leskelä Markku , Repo Timo
Published: February 2004

Bis(amino)cyclodiphosph(III)azanes cis‐[(RNH)(PN‐tBu)]2, R = 2,6‐iPr2C6H3 (2), 2‐tBuC6H4 (3), 2‐CF3C6H4 (4), 2,5‐tBu2C6H3 (5), Ph2CH (6), 2,4‐Me2C6H3 (7), 2,6‐Et2C6H3 (8), have been synthesized in the presence of Et3N by a nucleophilic substitution reaction of cis‐(ClPN‐tBu)2 (1) with the corresponding bulky aryl and alkylamines. The bis(amino)cyclodiphosph(III)azanes 2−8 adopt the thermodynamically stable cis‐configuration − a prerequisite for efficient metal complex formation. Deprotonation of bis(amino)cyclodiphosph(III)azanes with nBuLi slowly afforded the corresponding salts, cis‐[(2,4‐Me2C6H3N)(PN‐tBu)]2Li2(THF)2. The crystal structure of cis‐[(2,4‐Me2C6H3N)(PN‐tBu)]2Li2(THF)2 (9) consists of a heterocube of two lithium atoms, two nitrogen atoms and a cyclodiphosph(III)azane ring. Transmetallation of Li compounds by TiCl4 was unselective and led to a complex mixture of products. The direct reaction of cis‐bis(amino)cyclodiphosph(III)azanes with Ti(NMe2)4 is the most efficient method to prepare the corresponding titanium(IV) bis‐amido complexes cis‐[(RN)(PNtBu)]2Ti(NMe2)2 (11a, 12a, 14a, 15a). In the solid state, cis‐[(PhN)(PN‐tBu)]2Ti(NMe2)2 (11a) adopts a highly distorted trigonal‐bipyramidal configuration at the metal center. These bis‐amido titanium(IV) complexes have been subsequently transformed into the dichlorides cis‐[(RN)(PN‐tBu)]2TiCl2 (12−15) with Me3SiCl. After MAO activation the complexes possess moderate catalytic activity in ethene polymerization and produce linear polyethylene with molar masses of up to 2.6 × 106 g/mol and with narrow polydispersities. The catalytic activity and polymer properties depend strongly on the bulkiness of the ligand substituents; cis‐[(2,6‐iPr2C6H3N)(PN‐tBu)]2TiCl2 (14) gave the highest activity (231 kg PE/molcat × bar × h). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Iridium Complexes with Chiral and Achiral β‐Aminophosphane Ligands: Catalysts for >C=O Hydrogenation and H/D Exchange Involving both Homo‐ and Heterolytic H2 Activation
Authors: Dahlenburg Lutz , Götz Rainer
Published: February 2004

Chiral and achiral P,N‐chelated IrI complexes of the general type [(COD)Ir(P∩NR1R2)]BF4, where COD = η4‐1,5‐C8H12 and P∩NR1R2 = (1R,2R)‐, (1S,2S)‐, or (1R,2S)‐Ph2PC1H(Ph)C2H(Me)NR1R2 (NR1R2 = NH2, NHMe, NHCH2Ph, NHCHMe2, NMe2), Ph2PCH2CR2NH2 (R = H, Me), or 2‐Ph2PC6H4NHMe, have been prepared by treating [Ir(COD)2]BF4 with the required β‐aminophosphane in THF. The monolithiated ligands Ph2PCH2CMe2N(Li)H and 2‐Ph2PC6H4N(Li)Me interacted with [{(COD)Ir(μ‐Cl)}2] to give the neutral alkyl‐ and arylamido compounds [(COD)Ir(Ph2PCH2CMe2NH)] and [(COD)Ir(2‐Ph2PC6H4NMe)]. All IrI complexes [(COD)Ir(P∩NR1R2)]BF4 acted as catalysts for the direct hydrogenation of alkyl aryl ketones to the corresponding 1‐phenylalkanols, if combined with an alkaline or amine base in methanol under H2 (10−50 bar) between 25 and 50 °C. The reaction occurred with modest to moderate enantioselectivity (ca. 20−75% ee) if chelate complexes bearing the various optically active β‐aminophosphanes were used as catalysts. The base‐free amido complexes [(COD)Ir(P∩NR)] displayed similar catalytic activity to the combined systems [(COD)Ir(P∩NHR)]BF4−KOH (P∩NHR = Ph2PCH2CMe2NH2, 2‐Ph2PC6H4NHMe). The ability of both the cationic β‐amino‐ and the neutral β‐amidophosphane IrI complexes to undergo oxidative H2 addition and the observation of H2/D+ as well as H2/D2 exchange processes during catalysis provided evidence for a mechanism involving reversible “[IrIII(H)2−P∩NHR]+ ↔ [(η2‐H2)−IrIII(H)−P∩NR]+” proton‐to‐hydride transfer and heterolytic H2 cleavage on amino−dihydride and amido−dihydrogen−monohydride tautomers. The crystal structures of [(COD)Ir{(1S,2S)‐Ph2PCH(Ph)CH(Me)NHCH2Ph}]BF4·2THF, [(COD)Ir{1R,2S‐Ph2PCH(Ph)CH(Me)NHMe}]BF4·THF, and the orthometalated 18e IrI complex [(COD)Ir{(1R,2S)‐Ph2PCH(C6H4‐o)CH(Me)NHCHMe2}], which resulted from treatment of [(COD)Ir{(1R,2S)‐Ph2PCH(Ph)CH(Me)NHCHMe2}]BF4 with excess KOH, have been determined by single crystal X‐ray diffraction studies. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Manganese Oxydiacetate Complexes: Synthesis, Structure and Magnetic Properties
Authors: Grirrane Abdessamad , Pastor Antonio , Álvarez Eleuterio , Mealli Carlo , Ienco Andrea , Rosa Patrick , Montilla Francisco , Galindo Agustín
Published: February 2004

The aerobic aqueous solution syntheses and structures of monomeric and polymeric MnII complexes containing the oxydiacetate ligand [O(CH2COO)22− = oda] are reported. The magnetic properties of the polymeric products have also been investigated. The initially obtained species [{Mn(oda)(H2O)}·H2O]n (1) has been reacted with bidentate or tridentate N‐donor ligands such as o‐phenanthroline (phen), 2,2′‐bipyridine (bipy) and 2,2′:6,2′′‐terpyridine (terpy) to give the complexes [{Mn(oda)(phen)}·4H2O]n (2), [Mn(oda)(bipy)(H2O)]·2H2O (3) and [Mn(oda)(terpy)]·2H2O (4), respectively. Species 1−4 are the first Mn‐oda structures determined by X‐ray methods. In all cases, the oda acts as a tridentate ligand toward one metal and adopts the typical planar arrangement. However, while the 3 and 4 are monomers, 2 and 1 are polymers as oda exploits both atoms of its carboxylate groups to coordinate other metals; 1 consists of a three‐dimensional diamond‐type network, while 2 is one‐dimensional, consisting of an extended chain of {Mn(oda)(phen)} subunits. For both compounds, magnetic susceptibility measurements down to 2 K showed only weak antiferromagnetic interactions between high‐spin MnII ions. Despite the expectedly similar coordinating capabilities of N‐donor ligands, the bipy complex 3 is a monomer with the six‐coordination completed by one water ligand. The tridentate nature of simultaneously present oda and terpy ligands excludes the coordination of water in complex 4, the geometry of which is distorted from the octahedron, most likely due to a peculiar packing effect. Finally, the known five‐coordinate complex [MnCl2(terpy)] (5), a side product of our synthetic experiments, has also been structurally characterized. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis, Characterization and Near‐Infrared Photoluminescence of Monoporphyrinate Lanthanide Complexes Containing an Anionic Tripodal Ligand
Authors: He Hongshan , Guo Jianping , Zhao Zhixin , Wong Wai‐Kwok , Wong Wai‐Yeung , Lo Wing‐Kit , Li King‐Fai , Luo Li , Cheah Kok‐Wai
Published: February 2004

Twelve neutral stable complexes of ytterbium(III) and erbium(III) coordinated by anionic hydridotris(pyrazol‐1‐yl)borate andmeso‐tetraphenylporphyrinate, and its derivatives with different substituents in theparaposition of the phenyl groups, were prepared and characterized. Crystal structure analyses revealed that seven nitrogen atoms, four from the porphyrinate dianion and three from the anionic tripodal ligand, are symmetrically coordinated to the lanthanide ions. Photophysical investigations of the complexes showed an enhancement of near‐infrared photoluminescence as compared to aqua‐coordinated monoporphyrinate lanthanide complexes. The solvent effect and substituent effects on the photoluminescent properties of the complexes were also investigated (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).
Synthesis, Characterization and Properties of Transition Metal Pd/Pt [60]Fullerene Complexes Containing Phosphane Ligands − Crystal Structure of [Pd(η2‐C60){Ph2PCH2(CH2OCH2)2CH2PPh2}]
Authors: Song Li‐Cheng , Yu Guang‐Ao , Wang Hu‐Ting , Su Fu‐Hai , Hu Qing‐Mei , Song Ying‐Lin , Gao Ya‐Chen
Published: February 2004

A solution of C60 in toluene reacts with Pd(dba)2 or Pd2(dba)3 (dba = dibenzylideneacetone) and monophosphanes in a 1:1:2 molar ratio to give the corresponding Pd monophosphane fullerene derivatives [Pd(η2‐C60)L2] [L = P(2‐Fu)3 (Fu = furyl) 1; L = P(2‐Fu)Ph2 2; L = PPh2H 3; L = P(Fc)Ph2 (Fc = ferrocenyl) 4; L = P(Fc)2Ph 5], whereas reaction with M(dba)2 (M = Pd, Pt) and subsequent treatment with diphosphanes in 1:1:1 molar ratio afforded the corresponding Pd/Pt diphosphane fullerene complexes [Pd(η2‐C60){Ph2PCH2(CH2OCH2)nCH2PPh2}] (n = 1 6; n = 2 7; n = 3 8) and [Pt(η2‐C60){Ph2PCH2(CH2OCH2)nCH2PPh2}] (n = 1 9; n = 2 10; n =3 11). All the new fullerene complexes 1−11 were characterized by elemental analysis, IR, 1H NMR and 31P NMR spectroscopy, as well as by X‐ray diffraction analysis (for 7). The optical limiting properties of 3−5 were determined and the possible pathways for the “one pot” reactions leading to 1−11 are briefly discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis, Structural, Magnetic and Electrochemical Studies of Antiferromagnetically Coupled Symmetric Oxamidate‐Bridged Binuclear Copper(II) Complexes
Authors: Saravanakumar Duraisamy , Sengottuvelan Nallathambi , Narayanan Vengidusamy , Kandaswamy Muthusamy , Chinnakali Kandaswamy , Senthilkumar Gopal , Fun Hoong Kun
Published: February 2004

The new binuclear copper(II) complexes Cu2L1−3 and [Cu2L4,5](ClO4)2 were synthesized by reaction of the monomeric cis‐N,N′‐bis(3‐aminopropyl)oxamidatocopper(II) complex [Cu(oxpn)] with acetylacetone, benzoylacetone, salicylaldehyde, 2‐pyridinecarboxaldehyde and diacetyl monoxime in the presence of copper(II) acetate or perchlorate owing to the trans isomerisation of the cis‐oxamidato complex. The crystal structure of Cu2L1 consists of centrosymmetric binuclear copper(II) ions which are bridged by an oxamidato group in the trans conformation with a copper−copper distance of 5.121 Å. Each copper(II) ion occupies an inner site of the N2O2 donor with a distorted square‐planar environment. Electrochemical studies showed that two quasireversible one‐electron reduction waves are obtained in the cathodic region (E1pc = −0.48 to −1.02 V, E2pc = −1.08 to −1.34 V). The conproportionation constants Kcon for the mixed‐valence CuICuII complexes have been determined electrochemically. Room‐temperature magnetic‐moment studies of binuclear copper(II) complexes reveal the presence of a strong antiferromagnetic interaction (μeff = 1.14−1.24 μB) which is also observed from the broad spectra with g = 2.1. A variable‐temperature magnetic‐susceptibility study of the complexes 1 and 4 gives J values of −510 cm−1 and −497 cm−1 respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Dimeric Metallo‐Organic Supramolecular Quinoxaline Stacking Synthons
Authors: Heirtzler Fenton , Dias Sandra , Neuburger Markus
Published: February 2004

Condensation of ortho‐phenylene diamines with an unsymmetrical 2,6′‐bipyridyl‐2′′‐pyridyl α‐diketone (2) affords helical ligands 3a and 3b that self‐assemble in the presence of copper(I) to produce the helical, dimeric metallo‐organic complexes [3a2Cu2][PF6]2 and [3b2Cu2][PF6]2. These complexes have a flat, double‐decker‐like structure that results from atopomeric twisting in the ligand scaffolding, as confirmed by X‐ray crystal structural analysis on [3a2Cu2][PF6]2. This study also indicates a close parallel between the distances involved in inter‐ and intramolecular stacking phenomena. Detailed NMR spectroscopic analysis of both complexes indicates that their dications possess very closely related solution‐state structures. Achieving this self‐assembly program is an important step towards realizing dimerically self‐assembled metallo‐organic materials that have a discotic alignment. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Some Properties and Molecular Orbitals of Planar Heterodinuclear Phthalocyanines
Authors: Kobayashi Nagao , Ogata Hiroshi
Published: February 2004

The electronic absorption and magnetic circular dichroism (MCD) spectra, and differential pulse (DP) voltammograms of planar heterodinuclear phthalocyanine (Pc) dimers consisting of Pc and pyrazinoporphyrazine (PyZ), [Mt2PcPyZ (Mt = H2 and Zn)] and of Pc and naphthalocyanine (Nc), [Mt2PcNc (Mt = H2 and Co)] have been recorded. These dimers commonly show broad absorption bands between ca. 500 and 1000 nm, while the DP voltammograms suggest that the dimers are unstable towards oxidation, and that the two relatively independent chromophore units interact with one another. Molecular orbital (MO) calculations using the ZINDO/S Hamiltonian were performed in order to enhance the interpretation of the experimental results. Dimer orbitals were expressed by coupling the orbitals of the same symmetry, of the constituting mononucleates. It was suggested that for the HOMO of the dimers, the contribution of the more electron‐rich moiety is large, while conversely for the LUMO, the contribution of the more electron‐deficient moiety is large. The calculations suggested that there are three prominent transitions in the Q band region of the heterodimers. The intensity and position of these bands were suggested to be affected by the constituting mononucleates. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)