bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, Structure and Characterization of Two New Complexes [Cu2(C3H2O4)2(C4H4N2)]·2H2O and [Zn2(OH2)2(C3H2O4)2(C4H4N2)]
Authors: Zhang Xiutang , Lu Canzhong , Zhang Quanzheng , Lu Shaofang , Yang Wenbin , Liu Jiacheng , Zhuang Honghui 
Published: March 2003

AbstractTwo new complexes with three‐dimensional extended frameworks linked by pyrazine and malonate ligands, namely [Cu2(C3H2O4)2(C4H4N2)]·2H2O and [Zn2(OH2)2(C3H2O4)2(C4H4N2)], have been prepared and characterized by X‐ray crystallography, IR, EPR and UV/Vis spectroscopy, their magnetic properties and electrical conductivity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Solid‐State Adducts between C60 and Decamethylferrocene
Authors: Arrais Aldo , Diana Eliano , Gobetto Roberto , Milanesio Marco , Viterbo Davide , Stanghellini Pier Luigi 
Published: March 2003

AbstractCo‐deposition from concentrated solutions of C60 and Fe[C5(CH3)5]2 affords two solid products in different yields. The major product 1, in the form of regular shaped crystals, has been investigated by X‐ray diffraction, 13C CPMAS NMR and vibrational spectroscopy, which showed it to be a co‐crystalline adduct of C60 and Fe[C5(CH3)5]2 with no significant electron charge transfer between the two building blocks. The minor product 2, in the form of an amorphous powder, has been investigated by vibrational techniques. Both IR and Raman spectra are consistent with a solid structure in which electron transfer between the two units appears to be possible. ((© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis, Structure, and Characterization of [RAl(μ‐NHEt)(μ‐NEt)2Si(NHEt)]2 (R = Me, Et)
Authors: Kaskel Stefan , Lehmann Christian W. , Chaplais Gerald , Schlichte Klaus , Khanna Meik 
Published: March 2003

AbstractThe reaction between tetrakis(ethylamino)silane, Si(NHEt)4 (1) and trialkylaluminium compounds AlR3 [R = Me (2), R = Et (3)] results in partial deprotonation of 1 and subsequent formation of a new dimeric alumosilazane in high yield. Single‐crystal X‐ray analyses reveal the structure of two new four‐membered ring compounds [RAl(μ‐NHEt)(μ‐NEt)2Si(NHEt)]2 [R = Me (4), R = Et (5)]. They are isostructural and crystallize in the triclinic space group P$\bar 1$
(No. 2) with a = 8.3052(8) Å, b = 9.8323(9) Å, c = 10.324(1) Å, α = 115.498(4)°, β = 97.684(4)°, γ = 94.382(4)° (4) and a = 8.2319(3) Å, b = 9.3748(5) Å, c = 10.8221(6) Å, α = 107.035(2)°, β = 104.435(2)°, γ = 94.375(2)° (5). The alternating edge‐ and corner‐sharing SiN4‐ and AlCN3‐tetrahedra represent a new structural motif with μ‐NHEt and μ‐NEt groups in one double bridge. The compounds were further characterized by elemental analysis, mass spectrometry, and NMR and IR spectroscopy. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Structure and Reactivity Studies on Dinuclear Copper Complexes of the Ligand α,α′‐Bis{bis[1‐(1′‐methyl‐2′‐benzimidazolyl)methyl]amino}‐m‐xylene
Authors: Battaini Giuseppe , Casella Luigi , Gullotti Michele , Monzani Enrico , Nardin Giorgio , Perotti Angelo , Randaccio Lucio , Santagostini Laura , Heinemann Frank W. , Schindler Siegfried 
Published: March 2003

AbstractThe ligand α,α′‐bis{bis[1‐(1′‐methyl‐2′‐benzimidazolyl)methyl]amino}‐m‐xylene (L‐55) forms the complexes [CuI2(L‐55)(MeCN)2](PF6)2 (1) and [CuII2(L‐55)(OMe)2][ClO4]2 (2), in which an extremely weak axial amine interaction is imposed by the small five‐membered benzimidazole chelating ring units. This structural feature has been characterized by X‐ray crystal structure determination. In 1, the CuI centers are three‐coordinate with ligation from two benzimidazolyl and one acetonitrile N‐donors, in a slightly distorted trigonal arrangement. In 2, each CuII center has a distorted square‐planar geometry and coordinates to the benzimidazolyl N atoms and the bridging methoxy groups in the basal positions, with a much weaker interaction with the tertiary amine N in an apical position. These structural features affect the reactivities of the copper(I)− and copper(II)−L‐55 complexes toward dioxygen and hydrogen peroxide, respectively. [CuI2(L‐55)(MeCN)2]2+ does not produce a stable peroxo complex, but undergoes an irreversible oxidation to copper(II) species, while [CuII2(L‐55)(H2O)2]4+ reacts slowly with hydrogen peroxide to undergo regiospecific hydroxylation of the ligand at one benzylic carbon atom, which causes decomposition of the complex. [Cu2(L‐55)(H2O)2]4+ is easily converted into its bis(μ‐hydroxo) adduct [Cu2(L‐55)(OH)2]2+. This pH‐driven equilibrium was monitored by paramagnetic 1H NMR spectroscopy, and the solution magnetic properties of the complexes were determined by the Evans susceptibility method. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Novel Adducts of the Anticancer Drug Oxaliplatin with Glutathione and Redox Reactions with Glutathione Disulfide
Authors: Fakih Sarah , Munk Vivienne P. , Shipman Michelle A. , Murdoch Piedad del Socorro , Parkinson John A. , Sadler Peter J. 
Published: March 2003

AbstractReactions of [Pt(rac‐1,2‐DACH)Cl2], [Pt(1R,2R‐DACH)Cl2] and the anticancer drug oxaliplatin with the tripeptide glutathione and glutathione disulfide have been studied by HPLC, ESI‐MS and NMR methods. The same two major products are formed in each reaction: a thiolate‐bridged dimer and a novel thiolate‐bridged dinuclear macrochelate containing a nine‐membered chelate ring. Redox reactions of PtII anticancer drugs with biological disulfides are of potential importance to their mechanism of action. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis, Reactivity, Crystal Structures and Catalytic Activity of New Chelating Bisimidazolium‐Carbene Complexes of Rh
Authors: Poyatos Macarena , Mas‐Marzá Elena , Mata José A. , Sanaú Mercedes , Peris Eduardo 
Published: March 2003

AbstractA series of new bridging, chelating and pincer N‐heterocyclic carbenes of RhI and RhIII have been obtained under mild conditions. The compounds have been fully characterised and their crystal structures determined. The chelate‐pincer coordination of the ligands means that the stability of these compounds is significantly greater than other carbene complexes of Rh. The compounds have been tested in catalytic reactions such as hydrogen transfer from alcohols to ketones, and hydrosilylation of terminal olefins and alkynes; they show a high activity for both processes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Crystal Structure of Bis[acetone‐1‐naphthoylhydrazinato(−1)]copper(II) and Investigations of Intermolecular Interactions
Authors: Tomić Zoran D. , Leovac Vukadin M. , Pokorni Srdjan V. , Zobel Dieter , Zarić Snežana D. 
Published: March 2003

AbstractIn the crystal structure of the bis(acetone‐1‐naphthoylhydrazinato)copper(II) complex there are interactions of neighbouring molecules via naphthyl groups; the naphthyl group of one molecule interacts with the copper centre and CH3group of another molecule. The geometry of the crystal structure and dispositions of charges in the naphthyl and chelate rings indicate that there are stacking interactions between the aromatic ring and, not only the copper atom, but also the whole chelate ring. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
The First Structurally Characterized Trinuclear Dipicolinato Manganese Complex and its Conversion into a Mononuclear Species by Ligand Substitution
Authors: Ma Chengbing , Chen Changneng , Liu Qiutian , Liao Daizheng , Li Licun 
Published: March 2003

AbstractThe novel complex [Mn3(pdc)3(bpy)3(H2O)2] (1) (H2pdc = 2,6‐pyridinedicarboxylic acid, also known as 2,6‐dipicolinic acid; bpy = 2,2′‐bipyridine), has been obtained from the reaction of polymeric [MnK2(pdc)2(H2O)7]n (2) with bpy, and is the first example of a structurally characterized, trinuclear Mn complex incorporating dipicolinato ligands. All the MnII centers are seven‐coordinate in severely distorted pentagonal‐bipyramidal geometries. The conversion of 1 to mononuclear [Mn(pdc)(bpy)(Him)2] (3) (Him = imidazole), which is the first seven‐coordinate Mn complex with a Him ligand, has also been achieved by substitution of the labile ligand in 1 by Him. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Coordination Chemistry of Nitrile and Amino Pendant Arm Derivatives of [9]aneN2S and [9]aneNS2 with PdII and CuII
Authors: Arca Massimiliano , Blake Alexander J. , Lippolis Vito , Montesu Daniela R. , McMaster Jonathan , Tei Lorenzo , Schröder Martin 
Published: March 2003

AbstractPalladium(II) and copper(II) complexes [Pd(L1)Cl2], [Pd(L3)Cl2], [Cu(L1)Cl2], [Cu(L3)Cl2], [Pd(L2)][BF4]2, [Pd(L4)Cl]BF4, [Cu(L2)][NO3]2 and [Cu(L4)Cl]PF6 of the nitrile (L1 and L3) and amino (L2 and L4) pendant arm derivatives of 1‐thia‐4,7‐diazacyclononane ([9]aneN2S) and 7‐aza‐1,4‐dithiacyclononane ([9]aneNS2) have been prepared and fully characterised. In each case, a square‐pyramidal coordination sphere is observed at both metal ions with either one or two Cl− anions completing the donor set. The tridentate nine‐membered macrocyclic moiety adopts a [333] conformation in all the complexes obtained. The five‐membered chelate rings involving the donor atoms of the basal plane adopt a gauche configuration with very similar degrees of puckering. The “innocent” nitrile pendant arms in L1 and L3 do not bind to the metal ions, but still appear to influence the binding of the tridentate macrocyclic frameworks via the tertiary amine sites. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Intercalation of Poly(Ethylene Oxide) Derivatives into Layered Double Hydroxides
Authors: Leroux Fabrice , Aranda Pilar , Besse Jean‐Pierre , Ruiz‐Hitzky Eduardo 
Published: March 2003

AbstractMono‐ and bi‐functional guest molecules, poly(ethylene glycol)‐n‐alkyl‐3‐sulfopropyl diether (PEG‐AS) and poly(ethylene glycol)dicarboxylic acid (PEG‐DC), containing hydrophilic polyoxyethylene (PEO) chains of different ethylene oxide units (EOUs) are incorporated between the layers of Cu2Cr(OH)6Cl·nH2O hydrotalcite‐type materials. The intercalation compounds are characterized by chemical analysis, adsorption measurements, XRD, SEM, FTIR and 13C CP‐MAS spectroscopy. It is found that the polyoxyethylene chain of PEG‐DC distorts its helical symmetry when it is intercalated in the LDH galleries. The basal spacing of PEG‐AS nanocomposites is independent of the number, n, of EOUs in the polymer chain. In addition to changes in the IR bands, 13C CP‐MAS spectra are modified with new resonance peaks at more deshielded values. These facts suggest a strong interaction of polyether chains with the LDH inner‐surface, with the hydrophobic alkyl tail dangling into the interlamellar space. It is shown that the terminal functionalities dictate the arrangement of the PEO chains. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis of Tetrahemispheraplexes with Ammonium, Alkylammonium or Alkaline Metal Ions as Exohedral Guests via Self‐Assembly or Guest Exchange
Authors: Saalfrank Rolf W. , Demleitner Bernhard , Glaser Horst , Maid Harald , Reihs Stefan , Bauer Walter , Maluenga Monica , Hampel Frank , Teichert Markus , Krautscheid Harald 
Published: March 2003

AbstractTo study the interplay between the steric demand of the guest and the space available at the host, we have prepared the tetraammonium complexes {(NH4)4∩[Mg4(L1/2)6]} 1, tetrakis(methylammonium) complexes {(Me‐NH3)4∩[Mg4(L1/2)6]} 2, tetrakis(ethylammonium) complex {(Et‐NH3)4∩[Mg4(L1)6]} 3, and mixed sodium tris(ethylammonium) complex {Na(Et‐NH3)3∩[Mg4(L2)6]} 4. The tetrahemispheraplexes 1−4 were available in one‐pot syntheses. The tetrakis(alkylammonium) clusters {(R1−NH3)4∩[Mg4(L1)6]} 5 and the mixed diammonium‐bis(p‐methoxybenzylammonium) cluster {(NH4)2(R2−NH3)2∩[Mg4(L1)6]} 6, however, were prepared by exchange of the ammonium ions of 1a by alkylammonium ions. Similarly, exchange of the four ammonium ions of 1b by alkaline metal cations afforded the tetraalkaline metal tetrahemispheraplexes {M4∩[Mg4(L2)6]} 7.
Electrochemical Biosensors for Detection of Biological Warfare Agents
Authors: Shah Jasmin , Wilkins Ebtisam 
Published: March 2003

AbstractThis review discusses current development in electrochemical biosensors for detection of biological warfare agents. This could include bacteria, viruses and toxins that are aerosoled deliberately in air, food or water to spread terrorism and cause disease or death to humans, animals or plants. The rapid and unequivocal detection and identification of biological warfare agents is a major challenge for any government including military, health and other government agents. Reliable, specific characterization and identification of the microorganism from sampling location, either air, water, soil or others is required. This review will survey different types of electrochemical biosensors has been developed based on the following: i) Immunosensors ii) PCR (DNA base Sensor) iii) Bacteria or whole cell sensor and iv) Enzyme sensor. This article gives an overview of electrochemical biosensor for detection of biological warfare agents. Electrochemical biosensors have the advantages of sensitivity, selectivity, to operate in turbid media, and amenable to miniaturization. Recent developments in immunofiltration, flow injection, and flow‐through electrochemical biosensors for bacteria, viruses, and toxin detection are reviewed. The current research and development in biosensors for biological warfare agents detection is of interest to the public as well as to the defense is also discussed.
Nanodiamond Thin Film Electrodes: Metal Electro‐Deposition and Stripping Processes
Authors: Chi Hian Lau , Grehan Kieron J. , Goeting Christiaan H. , Compton Richard G. , Foord John S. , Marken Frank 
Published: March 2003

AbstractThe properties of a nanodiamond thin film deposit formed on titanium substrates in a microwave‐plasma enhanced CVD process, are investigated for applications in electroanalysis. The nanodiamond deposit consists of intergrown nano‐sized platelets of diamond with a high sp2 carbon content giving it high electrical conductivity and electrochemical reactivity. Nanodiamond thin film electrodes (of approximately 2 μm thickness) are characterized by electron microscopy and electrochemical methods. First, for a reversible one electron redox system, Ru(NH3)63+/2+, nanodiamond is shown to give well‐defined diffusion controlled voltammetric responses. Next, metal deposition processes are shown to proceed on nanodiamond with high reversibility and high efficiency compared to processes reported on boron‐doped diamond. The nucleation of gold is shown to be facile at edge sites, which are abundant on the nanodiamond surface. For the deposition and stripping of both gold and copper, a stripping efficiency (the ratio of electro‐dissolution charge to electro‐deposition charge) of close to unity is detected even at low concentrations of analyte. The effect of thermal annealing in air is shown to drastically modify the electrode characteristics probably due to interfacial oxidation, loss of active sp2 sites, and loss of conductivity.
Investigation of the Effect of Different Glassy Carbon Materials on the Performance of Prussian Blue Based Sensors for Hydrogen Peroxide
Authors: Ricci Francesco , Palleschi Giuseppe , Yigzaw Yirgalem , Gorton Lo , Ruzgas Tautgirdas , Karyakin Arkady 
Published: March 2003

AbstractThree different kinds of glassy carbon (GC‐R, GC‐K, GC‐G) were equally pretreated, further modified with electrochemically deposited Prussian Blue and used as sensors for hydrogen peroxide at an applied potential of −50 mV (vs. Ag|AgCl). Their performance was evaluated with respect to the following parameters: the coverage and electrochemistry of the electrodeposited Prussian Blue, the sensitivity and the lower limit of detection for hydrogen peroxide, and the operational stability of the sensors. GC‐R showed the best behavior concerning the surface coverage and the operational stability of the electrodeposited Prussian Blue. For this electrode the sensitivity for hydrogen peroxide (10 μM) was 0.25 A/M cm2 and the detection limit was 0.1 μM. Scanning electron microscopy was used to study the surfaces of the three electrodes before and after the electrodeposition of Prussian Blue and to search for the reason for the three different behaviors between the different glassy carbon materials. The Prussian Blue modified GC‐R was also used for the construction of a glucose biosensor based on immobilizing glucose oxidase in Nafion membranes on top of electrodeposited Prussian Blue layer. The operational stability of the glucose biosensors was studied in the flow injection mode at an applied potential of −50 mV (vs. Ag|AgCl) and alternatively injecting standard solutions of hydrogen peroxide (10 μM) and glucose (1 mM) for 3 h. For the GC‐R based biosensor a 2.8% decrease of the initial glucose response was observed.
Which Parameters Affect the Response of the Channel Biosensor?
Authors: Losic Dusan , Zhao Min , Shapter Joe G. , Gooding J. Justin 
Published: March 2003

AbstractThe important parameters in defining the response of the portable channel biosensor described previously are explored by connecting the portable flow cell to a gravity feed flow system and using a highly defined enzyme immobilization protocol which ensures the enzyme reaction is a surface reaction. The enzyme glucose oxidase (GOD) was immobilized by covalent attachment to a self‐assembled monolayer modified gold surface. As a glucose solution flowed down the rectangular duct defined by the flow cell, it passed over the enzyme layer where the enzyme reaction produced hydrogen peroxide. The hydrogen peroxide was swept further downstream to the detector electrode. The response of such an enzyme electrode was shown to be limited by mass transport of the cosubstrate oxygen to the enzyme layer. Increasing the amount of oxygen in the sample meant the response of the biosensor became limited by the enzyme kinetics. The influence of parameters such as flow rate, height of the channel, enzyme layer length and the gap between the enzyme layer and the detector electrode were explored.
Electrochemical Characterization of Poly(N‐acetylaniline)/Nafion Composite Film in Neutral and Basic Aqueous Solutions
Authors: Zheng Longzhen , Wu Shouguo , Lin Xiangqin , Shi Chunhua , Nie Lei , Rui Lei 
Published: March 2003

AbstractElectrochemical synthesis of poly(N‐acetylaniline) (PNAANI)/Nafion composite film was carried out by cyclic voltammetry (CV). Its surface morphology, which was evaluated by scanning electron microscopy (SEM), revealed that PNAANI was dispersed into the Nafion film uniformly. X‐ray photoelectron spectrum (XPS) of the composite film was also examined. The electroactivity of the composite film was high in neutral and basic solutions, and the stability of PNAANI/Nafion film in neutral and basic solutions was excellent.
A New Approximate Formulation of the Koutecky Function
Authors: Ruiz Morales Juan Carlos , Placeres Jesús César Rodríguez , Barrera Niebla Manuel , Trujillo Jacinto del Castillo Juan José , Germá Luis Rodríguez 
Published: March 2003

AbstractA new approximate formulation of the Koutecky function is proposed, with two new equations; one for the approximate calculation of the Koutecky function F(χ) in terms of its argument χ and the inverse χ=f [F(χ)]. Both use only two adjustable parameters, substantially more precise than the Smith‐McCord‐Hung and Oldham‐Parry formulations. The dependence χ=f [F(χ)] permits a more accurate general equation for polarographic waves to be deducted.
Characteristics of Cl‐ and Au‐Containing Nanocomplex and Its Effect on the Following Electrodeposition of Polypyrrole
Authors: Liu Yu‐Chuan , Liang Yu‐Sheng 
Published: March 2003

AbstractIn this study, polypyrrole (PPy) films were electrochemically deposited on gold substrates roughened by a triangular‐wave oxidation‐reduction cycle (ORC) with different anodic and cathodic vertexes in an aqueous solution containing 0.1 N NaCl. In ORC treatment, the Cl‐ and Au‐containing nanocomplex was formed on the surface of gold. The results indicate that the crystalline orientation and diameter of Au are significantly different before and after ORC treatment. Also the redox behavior in ORC, surface morphology formed and depth profile of Cl in the nanocomplex are influenced by the anodic and cathodic vertexes used in roughening Au. The roughened Au demonstrates an electrocatalytic activity for pyrrole polymerization. Correspondingly, the characteristics of PPy films electrodeposited on these roughened Au substrates are notable. They include the surface‐enhanced Raman scattering (SERS) effect shown, a higher conductivity obtained and an increase in oxidation level demonstrated.
A Study on the Electrochemical and Electrochemiluminescent Behavior of Homogentisic Acid at Carbon Electrodes
Authors: Chi Yuwu , Duan Jianping , Feng Zhao Zheng , Chen Hongqinq , Chen Guonan 
Published: March 2003

AbstractThe electrochemical oxidation and electrochemiluminescent behavior of homogentisic acid (HGA) has been studied in aqueous solutions over a wide pH range by linear sweep voltammetry, cyclic voltammetry, chronocoulometry at a glassy carbon electrode, by controlled potential electrolysis at a large area spectroscopic graphite electrode, and by spectroelectrochemistry at an optically transparent drilled holes graphite (DHG) electrode in a thin‐layer cell. The studies reveal that the electrochemical oxidation of HGA at carbon electrodes is a reversible process involving two‐electron, two‐proton transfer. In addition to the electrochemical oxidation, the chemical oxidation of HGA by dissolved oxygen was investigated by spectroscopic method combined with voltammetry. It was revealed that HGA is fairly stable in strongly acidic media but readily oxidized by dissolved oxygen in alkaline media giving rise to 1,4‐benzoquinone‐2‐acetic acid, the same product as that of electrooxidation of HGA. This oxidation product is stable in acidic, neutral and weakly alkaline media, but can further degrade in strongly alkaline media yielding oxalate as the final product. The electrochemiluminescent mechanism of HGA in the presence of Ru(bpy)32+ at a glassy carbon electrode was also investigated in detail, based on which a sensitive ECL method for determination of HGA was developed, and the detection limit was 3.0×10−8 mol L−1.
An Amperometric Biosensor Based on the Coimmobilization of Horseradish Peroxidase and Methylene Blue on a Carbon Nanotubes Modified Electrode
Authors: Xu Jin‐Zhong , Zhu Jun‐Jie , Wu Qiang , Hu Zheng , Chen Hong‐Yuan 
Published: March 2003

AbstractA novel hydrogen peroxide biosensor has been constructed based on the characteristics of the carbon nanotube. The multiwall carbon nanotube (MWNT) was used as a coimmobilization matrix to incorporate horseradish peroxidase (HRP) and electron transfer mediator methylene blue (MB) onto a glassy carbon electrode surface. Cyclic voltammetry and amperometric measurements were employed to demonstrate the feasibility of methylene blue as an electron carrier between the immobilized peroxidase and the surface of glassy carbon electrode. The amperometric response of this resulting biosensor to H2O2 shows a linear relation in the range from 4 μM to 2 mM. The detection limit was 1 μM when the signal to noise ratio is 3. The presence of dopamine and ascorbic acid hardly affects the sensitive determination of H2O2. This biosensor also possesses very good stability and reproducibility.