bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural and Magnetic Characterization of a Linear Trinuclear Copper Complex Formed through Ligand Sharing
Authors: Song Yufei , Gamez Patrick , Roubeau Olivier , Lutz Martin , Spek Anthony L. , Reedijk Jan 
Published: August 2003

AbstractReaction of bis(2‐hydroxybenzyl)‐1,3‐diamino‐2‐propanol (H2bhbdp) with copper perchlorate in methanol leads to the assembly of a trinuclear complex with the general formula [Cu3(bhbdp)2(CH3OH)2(ClO4)2] (1). The complex was characterized by X‐ray crystallography, Ligand Field, IR and ESR spectroscopy, and magnetic susceptibility. The structure of the complex contains a linear trinuclear array of copper ions [the Cu(1)−Cu(2)−Cu(1a) angle is 180° by symmetry], in octahedral, square planar and octahedral environments, respectively. The external Cu1 and Cu1a centers are coordinated by two amine nitrogens, two phenolate oxygen donors, one methoxide oxygen and one oxygen from a perchlorate, while the central Cu2 is coordinated by four phenolate oxygens through ligand sharing. A strong antiferromagnetic interaction between the adjacent CuII ions dominates the magnetic properties of 1 leading to an S = 1/2 ground state which is fully populated below 150 K. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Pendent Arm Formation and Extension accompanying Macrocycle Synthesis − A New Class of Ryongamines?
Authors: Harrowfield Jack , Kim Yang , Lee Young Hoon , Thuéry Pierre 
Published: August 2003

AbstractReaction of the CuII complex of the podand hexamine “sen”, CH3C(CH2NHCH2CH2NH2)3, with formaldehyde and nitroethane under basic conditions provides, as one of the principal products, a complex containing a new ligand which is not only macrocyclic but which has resulted also from reactions to extend one podand arm, to introduce an aminal bridge and to oxidise one of the donor‐N atom units to an imine. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Efficient Asymmetric Synthesis of Δ‐ and Λ‐Enantiomers of (Bipyridyl)ruthenium Complexes and Crystallographic Analysis of Δ‐Bis(2,2′‐bipyridine)(2,2′‐bipyridine‐4,4′‐dicarboxylato)ruthenium: Diastereoselective Homo‐ and Heterochiral Ion Pairing Revisited
Authors: Caspar Régis , Amouri Hani , Gruselle Michel , Cordier Christine , Malézieux Bernard , Duval Raphäel , Leveque Hubert 
Published: August 2003

AbstractIn our original article,[1] the captions for Figures 2, 3 and 4 (page 501) are incorrect. We wrongly attributed the CD curves with the solid line to the Δ‐enantiomers 4a, 4a and 5a and those with dotted lines to the �‐enantiomers 3b, 4b and 5b. The correct captions are as follows: Figure 2. CD curves for 3a (dotted line) and 3b (solid line) in acetonitrile Figure 3. CD curves for 5a (dotted line) and 5b (solid line) in acetonitrile Figure 4. CD curves for 4a (dotted line) and 4b (solid line) in acetonitrile
Seismic response of multi‐supported structures by proper orthogonal decomposition
Authors: Tubino Federica , Carassale Luigi , Solari Giovanni 
Published: August 2003

AbstractThe seismic analysis of structures is usually carried out considering the ground motion as fully‐correlated in space and determining the structural response by pseudo‐deterministic methods such as the response spectrum technique. Actually, the partial correlation of the seismic acceleration may influence heavily the behaviour of spatially extended structures, such as bridges, viaducts or pipelines. In order to take its partial correlation into account, the seismic ground motion is schematized as a stochastic process dependent on time and on space; the hypotheses of stationarity and homogeneity are used to obtain simple and general results. The influence of the partial correlation of the seismic ground motion on the structural response is investigated by introducing suitable Equivalent Spectra. The acceleration of the support‐points of the structure is represented by the Proper Orthogonal Decomposition (POD), defining the modes of the earthquake. The method is formulated for any kind of multi‐degree‐of‐freedom system and is applied, as a case study, to an ideal single‐storey multi‐supported frame with an axially rigid beam. In the case of two supports, the POD decouples the pseudo‐static and the dynamic contributions to the structural response. This property is preserved for structural systems with many supports, where only the lower modes of the earthquake, usually the first two POD modes, are responsible for the structural response. Copyright © 2003 John Wiley & Sons, Ltd.
Robust active vibration suppression control with constraint on the control signal: application to flexible structures
Authors: Forrai A. , Hashimoto S. , Funato H. , Kamiyama K. 
Published: August 2003

AbstractA unified mathematical framework, sustained by experimental results, is presented for robust controller design taking into account the constraint on the control signal. The design procedure is exemplified for an active vibration suppression control problem with applications to flexible structures. The considered experimental set‐up is a three‐storey flexible structure with an active mass driver placed on the last storey. First, the considered flexible structure is identified and the model's parametric uncertainties are deduced. Next, control constraints are presented for the robust control design problem, taking into account the restriction imposed on the control signal. Finally, the effectiveness of the control system is tested through experiments, when the input disturbance is assumed to be a sinusoidal one as well as a historical earthquake record (1940 El Centro record). Copyright © 2003 John Wiley & Sons, Ltd.
Seismic risk assessments and GIS technology: applications to infrastructures in the Friuli–Venezia Giulia region (NE Italy)
Authors: Codermatz Raffaella , Nicolich Rinaldo , Slejko Dario 
Published: August 2003

AbstractThis paper illustrates the seismic risk preliminary estimates of two different groups of structures located on the territory of the Friuli–Venezia Giulia region (NE Italy) : the first group includes some special industrial plants, and the second group includes bridges and tunnels belonging to the regional highway network. The part of the study on special industrial plants tries to evaluate the degree of expected damage, taking into account their structural typology and ground shaking expressed in terms of macroseismic intensity. The second part of the study is an application of the HAZUS methodology to the tunnels and bridges of a highway network: the combination of expected ground shaking and the construction characteristics lead to very different risk levels, especially when considering the bridges. The resulting damage levels to bridges and tunnels are still only indicative because of the fragility curves used in the evaluations: they were developed for existing bridge and tunnel structural typologies in the U.S.A. Moreover, both examples show the power of GIS technology in storing, elaborating, and mapping spatial data. Copyright © 2003 John Wiley & Sons, Ltd.
Comparison of spectral ratio techniques for estimation of site effects using microtremor data and earthquake motions recorded at the surface and in boreholes
Authors: Rodríguez Víctor H. S. , Midorikawa Saburoh 
Published: August 2003

AbstractThe authors apply soil response estimation techniques employing accelerograms for fifteen earthquakes recorded at the Yokohama Strong Motion Network and its vertical array of nine sites, plus microtremor data recorded at all 150 sites. Assessment of the reliability of surface to reference site spectral ratios, and horizontal to vertical spectral ratios of S‐waves, coda, and microtremors, relied on cross‐validation with both surface to borehole spectral ratios, and theoretical soil response functions for vertically incident SH plane waves calculated from the vertical array recordings and logging data, respectively. The results indicate the following: (1) the reference site method provides more accurate soil response estimations; (2) the H/V of microtremors provides relatively better soil response estimations than its S‐wave and coda counterparts; and (3) the H/V of microtremors provides coincident soil response estimations at two‐thirds of the sites when considering no more than ±30% mismatch in the determination of the predominant periods. The matching of parameters obtained from the analysis of microtremors, combined with their relatively low economic cost and the possibility of recording without strict spatial or time restrictions turns microtremors into a particularly appealing approach. Copyright © 2003 John Wiley & Sons, Ltd.
A method of calculating the non‐linear seismic response of a building braced with viscoelastic dampers
Authors: Choi Hyun , Kim Wook‐Bae , Lee Sang‐Jo 
Published: August 2003

AbstractBuildings are continually subject to dynamic loads, such as wind load, seismic ground motion, and even the load from internal utility machines. The recent trend of constructing more flexible high‐rise buildings underscores the importance of including viscoelastic dampers in building designs. Viscoelastic dampers are used to control the dynamic response of a building. If the seismic design is based only on the linear response spectrum, considerable error may occur when calculating the seismic response of a building; rubber viscoelastic dampers show non‐linear hysteretic damping that is quite different from viscous damping.This study generated a non‐linear response spectrum using a non‐linear oscillator model to simulate a building with viscoelastic dampers installed. The parameters used in the non‐linear damper model were obtained experimentally from dynamic loading tests. The results show that viscoelastic dampers effectively reduce the seismic displacement response of a structure, but transmit more seismic force to the structure, which essentially increases its seismic acceleration response. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of causal and acausal filters on elastic and inelastic response spectra
Authors: Boore David M. , Akkar Sinan 
Published: August 2003

AbstractWith increasing interest in displacement spectra and long‐period motions, it is important to check the sensitivity of both elastic and inelastic response spectra to the filtering that is often necessary to remove long period artifacts, even from many modern digital recordings. Using two records of very different character from the M=7.1, 1999 Hector Mine, California, earthquake, we find that the response spectra can be sensitive to the corner periods used in causal filtering, even for oscillator periods much less than the filter corner periods. The effect is most pronounced for inelastic response spectra, where the ratio of response spectra computed from accelerations filtered at 25 and 200 sec can be close to a factor of 2 for oscillator periods less than 5 sec. Published in 2003 by John Wiley Sons, Ltd.
Soil–structure interaction in yielding systems
Authors: Avilés Javier , Pérez‐Rocha Luis E. 
Published: August 2003

AbstractThe effects of soil–structure interaction in yielding systems are evaluated, including both kinematic and inertial interaction. The concepts developed previously for interacting elastic systems are extended to include the non‐linear behavior of the structure. A simple soil–structure system representative of code‐ designed buildings is investigated. The replacement oscillator approach used in practice to account for the elastic interaction effects is adjusted to consider the inelastic interaction effects. This is done by means of a non‐linear replacement oscillator defined by an effective ductility together with the known effective period and damping of the system for the elastic condition. To demonstrate the efficiency of this simplified approach, extensive numerical evaluations are conducted for elastoplastic structures with embedded foundation in a soil layer over elastic bedrock, excited by vertically propagating shear waves. Both strength and displacement demands are computed with and without regard to the effect of foundation flexibility, taking as control motion the great 1985 Michoacan earthquake recorded at a site representative of the soft zone in Mexico City. Results are properly interpreted to show the relative effects of interaction for elastic and yielding systems. Finally, it is demonstrated how to implement this information in the context of code design of buildings. Copyright © 2003 John Wiley & Sons, Ltd.
Formic Acid Catalyzed Rearrangement of Thevinols (=4,5‐Epoxy‐3,6‐dimethoxy‐α,17‐dimethyl‐6,14‐ethenomorphinan‐7‐methanols) and Their Vinylogous Analogues: Effects of 5β‐Methyl Substitution
Authors: Grundt Peter , Martinez‐Bermejo Fernando , Lewis John W. , Husbands Stephen M. 
Published: August 2003

AbstractIn a limited number of cases, 14‐alkenylcodeinones (=14‐alkenyl‐7,8‐didehydro‐4,5‐epoxy‐3‐methoxy‐17‐methylmorphinan‐6‐ones) can be obtained by formic acid treatment of thevinols (=4,5‐epoxy‐3,6‐dimethoxy‐α,17‐dimethyl‐6,14‐ethenomorphinan‐7‐methanols), but under these conditions the equivalent 14‐alkenyl‐7,8‐dihydrocodeinones undergo further rearrangement (Scheme 1 and Table). Introduction of a 5β‐methyl group allows the 18,19‐dihydrothevinol precursors to be rearranged to 14‐alkenyl‐7,8‐dihydrocodeinones, but similar manipulation of the vinylogues of these thevinols is generally unable to prevent full rearrangement to 5,14‐bridged thebainone derivatives.
Nucleotides. Part LXXI
Authors: Sigmund Harald , Pfleiderer Wolfgang 
Published: August 2003

AbstractA new labelling technique attaching fluorescein via a carbamoyl linker directly to the amino groups of the nucleobases was developed. The amino groups were first converted to the phenoxycarbonyl derivatives (→10, 15, 19, 58), which reacted under mild conditions with 5‐aminofluorescein to give the corresponding N‐[(fluorescein‐5‐ylamino)carbonyl] derivatives (→11–14, 16, 17, 20, 59, 60). The introduction of the 5‐aminofluorescein residue into properly protected adenylyl‐adenosine dimers (→39, 40) and trimer (→50) worked well, and final deprotection of these uniformly blocked precursors led on treatment with DBU (1,8‐diazabicyclo[5.4.0]undec‐7‐ene), in one step to dimer 41 and trimer 51. Synthesis of an appropriately protected monomeric phosphoramidite building block (→75) was more difficult, since introduction of the 2‐(4‐nitrophenyl)ethyl residue into the fluorescein moiety in 59 led mainly to trisubstitution to give 61 including the urea function. Formation of the adenylyl dimer 66 and trimer 67 proceeded in the usual manner by phosphoramidite chemistry; however, deprotection of 67 with DBU was incomplete since the O‐alkyl group at the urea moiety was found to be very stable. Finally, the appropriate phosphoramidite building block 75 could be synthesized by the sequence 59→72→73→74→75. The phosphoramidite 75 was used for the synthesis of dimer 77 and trimer 79 by solution chemistry, as well as for that of various oligonucleotides by the machine‐aided approach on solid support carrying the fluorophore at different positions of the chain (→84–87). The attachment of the fluorescein fluorophor via a short carbamoyl linker onto the 6‐amino group of 2′‐deoxyadenosine enables such molecules to function very well in fluorescence‐polarization experiments.
Synthesis and Biological Evaluation of 14‐Alkoxymorphinans. Part 19
Authors: Schüllner Falko , Meditz Ruth , Krassnig Roland , Morandell Günther , Kalinin Valery N. , Sandler Ellen , Spetea Mariana , White Angela , Schmidhammer Helmut , Berzetei‐Gurske Ilona P. 
Published: August 2003

AbstractThe 14‐O‐benzylnaltrexones 3–6 were prepared from naltrexone (2) in several steps. The novel compounds were biologically evaluated in radioligand binding and in [35S]GTPγS functional assays in comparison to the reference compound naltrexone. In the binding assay, compounds 3–6 exhibited preference for κ opioid receptors, while the parent compound naltrexone shows preference for μ receptors. In the functional assay, μ antagonist potency of compounds 3–6 was in the range of naltrexone, while κ antagonist potency was considerably higher for most novel compounds in comparison to naltrexone.
Induced Circular Dichroism and Magnetic Circular Dichroism Spectra of Maleimide and Related Molecules
Authors: Kawamura Masahiro , Higashi Miwako 
Published: August 2003

AbstractThe induced circular dichroism (ICD) spectra of the inclusion complexes of maleimide, phthalimide, and naphthalene‐2,3‐dicarboximide with β‐ or γ‐cyclodextrin (CDx) have been measured. The structure of the CDx inclusion complexes are interpreted by the signs and shapes of ICD spectra compared with the results of PPP calculations. In maleimide and naphthalene‐2,3‐dicarboximide, the ICD spectra of the β‐CDx inclusion complex are very similar to those of the γ‐CDx inclusion complex in spite of the differences in dimensions between the cavity of β‐CDx and that of γ‐CDx. In phthalimide, the ICD spectra of the β‐CDx inclusion complex are very different from those of the γ‐CDx inclusion complex. The split‐type ICD bands at 220–235 nm show that the dimer of phthalimide is formed in the presence of β‐CDx.
Metabolism of Deuterated Isomeric 6,7‐Dihydroxydodecanoic Acids in Saccharomyces cerevisiae – Diastereo‐ and Enantioselective Formation and Characterization of 5‐Hydroxydecano‐4‐lactone (=4,5‐Dihydro‐5‐(1‐hydroxyhexyl)furan‐2(3H)‐one) Isomers
Authors: Garbe Leif‐A. , Tressl Roland 
Published: August 2003

AbstractThe chemical synthesis of deuterated isomeric 6,7‐dihydroxydodecanoic acid methyl esters 1 and the subsequent metabolism of esters 1 and the corresponding acids 1a in liquid cultures of the yeast Saccharomyces cerevisiae was investigated. Incubation experiments with (6R,7R)‐ or (6S,7S)‐6,7‐dihydroxy(6,7‐2H2)dodecanoic acid methyl ester ((6R,7R)‐ or (6S,7S)‐(6,7‐2H2)‐1, resp.) and (±)‐threo‐ or (±)‐erythro‐6,7‐dihydroxy(6,7‐2H2)dodecanoic acid ((±)‐threo‐ or (±)‐erythro‐(6,7‐2H2)‐1a, resp.) elucidated their metabolic pathway in yeast (Tables 1–3). The main products were isomeric 2H‐labeled 5‐hydroxydecano‐4‐lactones 2. The absolute configuration of the four isomeric lactones 2 was assigned by chemical synthesis via Sharpless asymmetric dihydroxylation and chiral gas chromatography (Lipodex ® E). The enantiomers of threo‐2 were separated without derivatization on Lipodex ® E; in contrast, the enantiomers of erythro‐2 could be separated only after transformation to their 5‐O‐(trifluoroacetyl) derivatives. Biotransformation of the methyl ester (6R,7R)‐(6,7‐2H2)‐1 led to (4R,5R)‐ and (4S,5R)‐(2,5‐2H2)‐2 (ratio ca. 4 : 1; Table 2). Estimation of the label content and position of (4S,5R)‐(2,5‐2H2)‐2 showed 95% label at C(5), 68% label at C(2), and no 2H at C(4) (Table 2). Therefore, oxidation and subsequent reduction with inversion at C(4) of 4,5‐dihydroxydecanoic acid and transfer of 2H from C(4) to C(2) is postulated. The 5‐hydroxydecano‐4‐lactones 2 are of biochemical importance: during the fermentation of Streptomyces griseus, (4S,5R)‐2, known as L‐factor, occurs temporarily before the antibiotic production, and (−)‐muricatacin (=(4R,5R)‐5‐hydroxy‐heptadecano‐4‐lactone), a homologue of (4R,5R)‐2, is an anticancer agent.
Low Temperature 1H‐, 19F‐, and 31P‐PGSE Diffusion Measurements. Applications to Cationic Alcohol Complexes
Authors: Martínez‐Viviente Eloísa , Pregosin Paul S. 
Published: August 2003

AbstractThe problems associated with low‐temperature pulsed‐gradient spin‐echo (PGSE) NMR diffusion measurements are discussed. The influence of convection is overcome by employing a coaxial insert inside a normal 5 mm NMR tube. By means of this configuration, correct diffusion constants and temperature‐independent hydrodynamic radii can be obtained. Low‐temperature 1H‐, 19F‐, and 31P‐PGSE measurements on unstable cationic alcohol complexes of palladium and tungsten (in MeOH and CH2Cl2) are reported. For [W(Cp)(adamant‐1‐ol)(CO)3](CF3SO3), a strong hydrogen bond between the alcohol OH group and the trifluoromethanesulfonate anion is demonstrated.
Methyl Fluorocarbonyl Disulfide (FC(O)SSMe): A Theoretical Study on the Structural and Conformational Properties of Its Neutral Ground State and Lowest‐Lying Cationic State
Authors: Erben Mauricio F. , Della Védova Carlos O. 
Published: August 2003

AbstractIn this work, we present a theoretical study on the structural and conformational properties of FC(O)SSMe in its neutral and cationic ground states. The structure of the neutral molecule, as deduced from HartreeFock (HF), Density Functional Theory (DFT), and MøllerPlesset (MP2) methods, agrees with the experimentally determined value for the CSSC dihedral angle (CS bonds gauche with respect to each other) and with the syn preference of the SSCO dihedral angle (CO bond syn with respect to the SS bond). The calculated values for these two dihedral angles are 81.9 and 4.2 degrees, respectively. From the energy difference of the anti vs. syn conformer computed at the CCSD(T)/6‐311++G** level of theory, a 3% contribution of a less‐stable conformer at room temperature is proposed. The potential barrier of rotation about the SS bond is 5.7 kcal/mol (B3PW91/6‐311++G** approximation). The FC(O)SSMe molecule adopts a planar structure after ionization, the anti conformer (CSSC dihedral angle 180°) being the most‐stable form. For the first ionization of the title compound, the adiabatic ionization potential (IPad) derived from the three mentioned theoretical methods (using the 6‐311++G** basis sets) is 8.48, 9.06, and 8.99 eV, whereas the vertical ionization potential (IPver) is 8.96, 9.79, and 9.62 eV, respectively (experimental value: 9.0 eV). The results are compared with previous experimental studies carried out for the neutral and charged species interpreted on the basis of the Natural Bond Orbital (NBO) analysis. From these calculations, the importance of the anomeric and mesomeric effects becomes evident. The preferred conformation can be quantitatively explained by evaluation of donor/acceptor interaction energies.
Synthesis of Polyfunctional Aromatic Ring Systems (Phloroglucide Analogs) under Microwave Irradiation
Authors: Khalafi‐Nezhad Ali , Rad Mohammad Navid Soltani , Hakimelahi Gholam Hossein 
Published: August 2003

AbstractAn efficient and rapid synthesis of phloroglucide analogs under microwave irradiation is described. The solid‐phase condensation reaction of the 4‐halo‐2,6‐bis(hydroxymethyl)phenols 1a,b with other substituted phenols in the presence of ZnCl2 afforded the target molecules in much higher yields than by classical solution‐phase synthesis and allowed us to prepare new phloroglucide analogs possessing sensitive functional groups difficult to access by established means.