bluuebunny/crossref_metadata_2025_split huggingface dataset:
Über das Hydratisomer Gd3(H2ClCCOO)9(H2O)5
Authors: Rohde Alexander , Urland Werner 
Published: December 2003

AbstractOn the Hydrate Isomer Gd3(H2ClCCOO)9(H2O)5Single crystals of Gd3(H2ClCCOO)9(H2O)5 have been obtained by reaction of Gd2O3 with an aqueous solution of H2ClCCOOH. The compound crystallizes in the monoclinic space group P 21/a (Z = 4, a = 1438.2(3), b = 1870.2(4), c = 1475.9(3) pm, β = 95.37(2)°). There are three kinds of crystallographically independent Gd3+ ions. All of them are ninefold coordinated, two of them are each coordinated by a tricapped trigonal prism, whereas the third one is coordinated by a monocapped square antiprism. The compound represents an hydrate isomer of the known Gd3(H2ClCCOO)9(H2O)4 ·H2O.
Synthesis, Crystal Structures and Thermal Properties of the New Copper(I) Pseudohalide Coordination Polymers Catena[(μ2‐thiocyanato‐N, S)‐(1‐ethyl‐2‐methylpyrazine‐N)]copper(I) and Poly[(di‐μ2‐thiocyanato‐N, S)‐(μ2‐1‐ethyl‐2‐methylpyrazine‐N, N′)]dicopper(I)
Authors: Näther Christian , Jeß Inke , Kowallik Petra 
Published: December 2003

AbstractReaction of copper(I) thiocyanate with 1‐ethyl‐2‐methyl‐pyrazine in acetonitrile yields the two new coordination polymers catena[(μ2‐thiocyanato‐N, S)‐(1‐ethyl‐2‐methylpyrazine‐N)] copper(I)(I) and poly[(di‐μ2‐thiocyanato‐N, S)‐(μ2‐1‐ethyl‐2‐methylpyrazine‐N, N′)] di‐copper(I) (II). The crystal structure of I is composed of CuSCN double chains in which each copper atom is connected to two thiocyanate anions and two 1‐ethyl‐2‐methyl‐pyrazine ligands. In this compound only one nitrogen atom of the 1‐ethyl‐2‐methyl‐pyrazine ligand is involved in copper coordination. The crystal structure of II is composed of CuSCN layers that are connected by the N‐donor ligands via μ‐N, N′ coordination into a three‐dimensional coordination network. On heating the amine rich compound I loses half of the ligands and transforms into the amine‐poorer compound II which occurs as an intermediate. Compound II decomposes on further heating to CuSCN. This reaction was investigated using simultaneous differential thermoanalysis and thermogravimetry coupled with mass spectroscopy and temperature dependent X‐ray powder diffraction.
Co[(C6H10)(NH3)2][C6H2(COO)4] · 2H2O und Zn[(C6H12)(NH3)2][C6H2(COO)4] · 1/2H2O ‐ Zwei zeolithartige dreidimensionale Koordinationspolymere
Authors: Köferstein Roberto , Robl Christian 
Published: December 2003

AbstractMonokline Einkristalle von Co[(C6H10)(NH3)2][C6H2(COO)4]·2H2O (1) wurden in wässeriger Lösung bei 80 °C erhalten. Raumgruppe C2/c (Nr. 15), a = 1065.92(8), b = 1568.97(9), c = 1140.88(9) pm, β = 90.101(6)°, V = 1.9080(2) nm3, Z = 4. Co2+ besetzt eine zweizählige kristallographische Achse und ist verzerrt tetraedrisch durch vier Sauerstoffatome der Pyromellitatanionen koordiniert (Co‐O 197.87(12) und 200.64(12) pm). Aus der Verbindung von Co2+ mit C6H2(COO)44‐ resultiert ein dreidimensionales Koordinationspolymer mit kanalartigen Hohlräumen, die von Wassermolekülen und (C6H10)(NH3)22+‐Kationen belegt sind, welche die negative Überschußladung des Gerüstes kompensieren. Bei der thermogravimetrischen Untersuchung an Luft erwies sich das Anhydrid der Verbindung zwischen 198 und 361 °C als stabil. Die weitere Zersetzung führte zu CoO. Zn[(C6H12)(NH3)2][C6H2(COO)4] · 1/2H2O (2) wurde analog zu 1 unter Verwendung von 1, 6‐Diaminohexan hergestellt. Raumgruppe P21/n (Nr. 14), a = 1087.78(8), b = 1515.18(11), c = 1162.21(10) pm, β = 96.249(7)°, V = 1.9042(3) nm3, Z = 4. Zn2+ ist ebenfalls wie Co2+ tetraedrisch von vier Sauerstoffatomen der Pyromellitatanionen koordiniert (Zn—O 195.0(4) ‐ 197.8(4)). Aus der Verknüpfung von Zn2+ mit den Pyromellitatanionen resultiert ein dreidimensionales Gerüst, das sehr große Ähnlichkeiten mit der Struktur von 1 aufweist und in seinen Hohlräumen (C6H12)(NH3)22+‐Kationen und Wassermoleküle beherbergt. 2 war in wasserfreier Form zwischen ca. 120 und 340 °C stabil, anschließend erfolgte die Zersetzung zu ZnO, die bei 700 °C abgeschlossen war.
Photochemische Reaktionen von Cyclopentadienylbis(ethen)rhodium mit 2‐ und 4‐Vinylpyridin
Authors: Müller Jörn , Hirsch Cordula , Ha Kwang 
Published: December 2003

AbstractBei der UV‐Bestrahlung von [CpRh(C2H4)2] (1) (Cp = η5‐C5H5) in Hexan in Gegenwart von 2‐Vinylpyridin erfolgt einerseits schrittweise Substitution der Ethenliganden durch die Vinylgruppe unter Bildung der einkernigen Komplexe [CpRh(C2H4)(η2‐C2H3C5H4N)] (2) und [CpRh(η2‐C2H3C5H4N)2] (3). In zwei weiteren zweikernigen Reaktionsprodukten tritt andererseits zusätzlich N‐Koordination auf, nämlich in [{CpRh(μ‐η1:η2‐2‐vinylpyridin)}2] (4) und in [(μ‐H)(μ‐η1:η1:η2‐2‐vinylidenpyridin)(CpR h)2] (5). DieVerbindung 5 enthält neben einer unsymmetrischen Hydridobrücke einen durch C‐H‐Aktivierung des Vinylsubstituenten in der β‐Position entstandenen Aza‐rhoda‐cyclopentadien‐Ring. Die Photoreaktion von 1 mit 4‐Vinylpyridin liefert dagegen neben Oligomeren des Liganden ausschließlich den zu 2 analogen Komplex 6. Die neuen Verbindungen wurden analytisch und spektroskopisch charakterisiert, im Falle von 5 auch durch Röntgenstrukturanalyse.
Self‐assembly of a Novel trans‐Oxamidato‐bridged Copper(II) Compound with a Neutral Oxamidate‐Ester Ligand as a Spacer. Crystal Structure, Spectroscopy, and Magnetism of a Chain of Dinuclear Units
Authors: van Albada Gerard A. , Mohamadou Aminou , Reedijk Jan , Kooijman Huub , Spek Anthony L. 
Published: December 2003

AbstractThe structural, spectroscopic and magnetic properties of a new dinuclear‐based polymeric oxamidato‐bridged CuII compound, [Cu2(H2oxen)(oxen)(H2O)(ClO4)2]n(C2H6O)2n (in which H2oxen = N, N′‐bis(2‐aminoethyl)oxamide) is reported. The X‐ray structure analysis reveals the triclinic space group P1¯ with a = 7.0857(10) , b = 10.333(2), c = 11.285(2)Å, α = 71.599(7), β = 83.047(7), γ = 83.238(8)°, Z = 2. The coordination around the CuII ion is distorted octahedral, the basal plane is formed by two N atoms and one O atom of the deprotonated ligand (distances in the range 1.919(2), 2.028(2)Å) and one N‐atom of the second ligand, which acts as the “spacer” ligand (Cu‐N distance 1.971(2)Å). The apical positions are occupied by a water molecule (Cu‐O1 distance 2.445(2)Å) and an O atom of a perchlorate anion at a semi‐coordination distance of 2.912(2)Å. The dinuclear units are connected with a H2oxen ligand forming an indefinite 2‐D polymeric array. The Cu‐Cu separation through trans‐oxen ligand within de dinuclear entity is 5.2548(11)Å and the Cu‐Cu‐ separation through the H2 oxen‐spacer ligand is 11.458(2)Å. Magnetic susceptibility measurements have been performed over a temperature range of 5‐350 K and resulted in an antiferromagnetic behaviour with a singlet‐triplet energy gap J = ‐558.1 cm‐1.
Synthesis and Structural Characterization of a New Tetranuclear Macrocyclic Copper(I) Complex
Authors: Utz Diana , Heinemann Frank W. , Mukherjee Jhumpa , Mukherjee Rabindranath , Schindler Siegfried 
Published: December 2003

AbstractA tetranuclear copper(I) complex [Cu4(L2)Cl4] with a new macrocyclic ligand derived from the [4+4] condensation of ethylenediamine and isophthalaldehyde was synthesized and structurally characterized. The copper(I) ions are coordinated in a distorted tetrahedral manner by two imine nitrogen and two chloro donor atoms. The copper copper separation is 3.056(2)Å.
Synthesis, Structure, and Spectroscopic Properties of a Dinuclear FeIII(μ2‐O)FeIII Complex Using a Strongly Electron‐Donating Ligand: Implications for the Generation of New High‐Valent Species
Authors: Glaser Thorsten , Pawelke Roland H. , Heidemeier Maik 
Published: December 2003

AbstractThe dinuclear complex [LFeIII(μ2‐O)FeIIIL] (1) (H2L = ‐N, N′‐dimethyl‐N, N′‐bis(3, 5‐di‐tert‐butyl‐2‐hydroxybenzyl)‐1, 2diaminoethane) has been synthesized and structurally characterized by elemental analysis, MALDI‐TOF MS, FTIR, and single crystal X‐ray diffraction. The electronic structure has been investigated by means of electronic absorption, electrochemistry, Mössbauer spectroscopy, and variable‐temperature magnetic susceptibility measurements. The iron atoms are five‐coordinated in an idealized square‐pyramidal coordination environment. The N2O2 donor set of L2— forms the equatorial plane while the bridging oxo‐ligand is in the axial position forming a linear Fe—O—Fe unit. The Mössbauer spectrum at 80 K consists of one quadrupole doublet with an isomer shift of 0.45 mm s—1 and a quadrupole splitting of 1.22 mm s—1. The low isomer shift is indicative of highly covalent metal‐ligand bonds resulting in electron‐rich FeIII high spin centers (Si = 5/2). Variable‐temperature magnetic susceptibility measurement reveals an intramolecular antiferromagnetic coupling (J = —96 cm—1). Strong LMCT transitions in the vis‐region of the absorption spectrum are in accordance to the highly covalent nature of the FeIII sites. The electrochemical analysis reveals two oxidative electron‐transfer waves at E1/2 = +0.28 V and E1/2 = +0.45 V vs Fc+/Fc. These experimental data provide insight into the electronic structure of the dinuclear complex and into the ability of the strongly electron‐donating ligand L2— to stabilize high‐valent dinuclear iron species.
Growth of Calcite Single Crystals Underneath Monolayers of 5, 11, 17, 23‐Tetra‐t‐butyl‐25, 26, 27, 28‐tetrakis(carboxymethoxy)calix[4]arene
Authors: Volkmer Dirk , Fricke Marc 
Published: December 2003

AbstractThe amphiphilic 5, 11, 17, 23‐tetra‐t‐butyl‐25, 26, 27, 28‐tetrakis(carboxymethoxy)calix[4]arene (1) forms stable monolayers at the air‐water interface which serve as template to induce growth of CaCO3(calcite) single crystals. The nucleation density and the preferred orientation(s) of calcite single crystals depend on the surface pressure applied to the monolayer. Models of the pressure‐dependant aggregation of amphiphiles at the air‐water interface are derived from the crystal structures of the novel Ca coordination compounds [(Ca(C52H60O12))2Ca(H2O)2(CH3OH)3Ca(H2O)2(CH3OH)2]·12CH3OH·4H2O (2) and [Ca(C52H60O12)Ca(H2O)2.5(MeOH)0.5]·7H2O·CH3OH (3). Structural data are analyzed in terms of supramolecular packing arrangements and Ca coordination motifs of the constituting amphiphilic macrocycles.
Synthesis and Characterization of a Siderophore‐based Luminescent Sensor for Molybdate
Authors: Jedner Stephanie B. , Perutz Robin N. , Duhme‐Klair Anne‐K. 
Published: December 2003

AbstractBy connecting a bidentate siderophore to a luminescent tris(2, 2′‐bipyridyl)ruthenium(II) unit, a modular sensor reagent has been synthesised and characterised which selectively signals the presence of molybdate in solution through a decrease in emission intensity.
Bis[acetylacetonato(1—)‐O, O]di(cyanato‐N)silicon(IV): A Neutral Hexacoordinate Silicon Complex with Two Cyanato‐N Ligands
Authors: Tacke Reinhold , Bertermann Rüdiger , Penka Martin , Seiler Oliver 
Published: December 2003

AbstractThe neutral hexacoordinate silicon(IV) complex cis‐[(acac)2Si(NCO)2] (cis‐8; acac = acetylacetonato‐O, O) was synthesized, starting from Si(NCO)4. Compound cis‐8 was structurally characterized in the solid state (13C, 15N, and 29Si MAS NMR; crystal structure analysis) and in solution (1H, 13C, and 29Si NMR). The experimental investigations were complemented by computational studies (RI‐MP2 geometry optimizations of cis‐8 and trans‐8 and of the corresponding cyanato‐O isomers cis‐[(acac)2Si (OCN)2] (cis‐9) and trans‐[(acac)2Si(OCN)2] (trans‐9); calculations of the 29Si NMR chemical shifts of cis‐8, trans‐8, cis‐9 and trans‐9 using the optimized structures).
Halogen‐Halogen‐Wechselwirkungen im Kristall von 2 ImIBr · Br‐CF2CF2‐I (Im = 1, 3‐Diisopropyl‐4, 5‐dimethylimidazoly [1]
Authors: Kuhn Norbert , Abu‐Rayyan Ahmed , Steimann Manfred 
Published: December 2003

AbstractInteractions between Halogen Atoms in the Crystal of 2 ImIBr · Br‐CF2CF2‐I (Im = 1, 3‐Diisopropyl‐4, 5‐dimethylimidazoly[1]2, 3‐Dihydro‐1, 3‐diisopropyl‐4, 5‐dimethylimidazol‐2‐ylidene (3, Im) reacts with Br‐CF2CF2‐I to give the adduct 2 Im‐I‐Br · Br‐CF2CF2‐I (5). The crystal structure analysis of 5 exhibits near linear C‐I‐Br interactions in addition to short Br‐Br and Br‐I contacts to the Br‐CF2CF2‐I fragment.
Biometallorganische Koordinationsverbindungen: Synthese und Strukturen von Übergangsmetallkomplexen mit Tropidinyl‐ und Tropidin‐Liganden
Authors: Tamm Matthias , Kunst Andreas , Hahn F. Ekkehardt , Pape Tania , Fröhlich Roland 
Published: December 2003

AbstractDie Deprotonierung des Alkens Tropidin bzw. 8‐Methyl‐8‐azabicyclo[3.2.1]oct‐2‐en (1) mit n‐Butylnatrium führt in guten Ausbeuten zum Natriumsalz des Tropidinyl‐Anions (2). Die Reaktion mit Me3SnCl liefert 4‐Trimethylstannyltropidin (3), welches als Ausgangsmaterial für den Aufbau von Tropidinyl‐Übergangsmetallkomplexen dient. Die Komplexe [(2)M(CO)3] (M = Mn, 4a; M = Re, 4b) können durch Umsetzung von 3 mit den Bromiden [M(CO)5Br] synthetisiert werden, während [(2)Ru(PPh3)2Cl] (5) durch Reaktion mit [Ru(PPh3)3Cl2] erhalten wird. Der Tropidinyl‐Ligand 2 koordiniert in den Komplexen 4 und 5 sowohl über das verbrückende Stickstoffatom als auch über die drei allylischen Kohlenstoffatome und kann mit seinen getrennten 2σ‐ und 4π‐Elektronen‐Donorzentren als Cp‐analoger Ligand aufgefaßt werden. Die Reaktion des Chloro‐Komplexes 5 mit Superhydrid, Li[BEt3H], ergibt das Hydrid [(2)Ru(PPh3)2H] (6). Bei der Kristallisation von 6 wird der Peroxo‐Komplex [(1)Ru(PPh3)2(O2)] (7) isoliert, der den Tropidin‐Liganden 1 enthält. Die Komplexe 4a, 5·CH2Cl2 und 7 konnten durch Einkristall‐Röntgenstrukturanalysen charakterisiert werden.
Stability of new implicit iteration procedures for a class of nonlinear set‐valued mixed variational inequalities
Authors: Fang Y.‐p. , Deng C.‐x. 
Published: December 2003

AbstractIn this paper, we develop some new implicit iteration procedures for solving a class of nonlinear set‐valued mixed variational inequalities. We also introduce a concept of stability of implicit iteration procedures and discuss the convergence and stability of the iterative sequences generated by the algorithms. The results presented in this paper extend and improve the corresponding results of Huang [11].
Solution of the Lyapunov matrix equation for a system with a time‐dependent stiffness matrix
Authors: Pommer C. , Kliem W. 
Published: December 2003

AbstractThe stability of the linearized model of a rotor system with non‐symmetric strain and axial loads is investigated. Since we are using a fixed reference system, the differential equations have the advantage to be free of Coriolis and centrifugal forces. A disadvantage is nevertheless the occurrence of time‐dependent periodic terms in the stiffness matrix. However, by solving the Lyapunov matrix equation we can formulate several stability conditions for the rotor system. Hereby the positive definiteness of a certain averaged stiffness matrix plays a crucial role.
Elliptic integral solutions of variable‐arc‐length elastica under an inclined follower force
Authors: Chucheepsakul S. , Phungpaigram B. 
Published: December 2003

AbstractThis paper presents exact closed‐formed solutions using elliptic integrals for large deflection analysis of elastica of a beam with variable arc‐length subjected to an inclined follower force. The beam is hinged at end but slides freely over the support at the other end. In the undeformed state, the inclined follower force applied at any distance from the hinged end making an angle γ with respect to vertical axis while in the deformed state its direction remains at an angle γ from the normal to the beam axis. The set of nonlinear equations is obtained from the boundary conditions, and solved iteratively for the solutions. The effect of the direction and the position of the follower force on the beam bending behaviour is demonstrated. Comparisons of equilibrium configurations of the beam under non‐follower force and follower force are also given.
Adolescent religiosity and sexuality: an investigation of reciprocal influences
Authors: Hardy Sam A , Raffaelli Marcela 
Published: December 2003

ABSTRACTThe present study examined potential bi‐directional associations between religiosity and first sexual intercourse. The sample, drawn from the National Longitudinal Survey of Youth, included 303 teens (22% Hispanic, 35% Black, 43% White; 53% male) aged 15–16 in 1996 and 17–18 in 1998. All teens included in the sample were virgins at Time 1. In the longitudinal analyses, higher Time 1 religiosity (a composite of importance of religion and frequency of church attendance) was associated with a lower likelihood of first sexual intercourse between Time 1 and Time 2. However, transition to sexual activity between Time 1 and Time 2 was not significantly related to Time 2 religiosity. Thus, results do not support a bi‐directional association; instead, it appears that teens with higher levels of religiosity tend to delay sexual involvement more than those with lower levels of religiosity.
Young male prisoners in a Young Offenders’ Institution: their contact with suicidal behaviour by others
Authors: Hales H , Davison S , Misch P , Taylor P.J 
Published: December 2003

ABSTRACTPrison suicide rates are increasing. The impact of witnessing a suicide or how many people do so is unknown. The aim of this study was to find how many young people detained in a Young Offenders’ Institution (YOI) have had contact with another's suicide attempt and to test for association between this and own self‐harming behaviour. A questionnaire, developed for the project, was distributed within a YOI. 74% (355/480) responded.One hundred and fifty‐one (43%) of the young men reported that they knew someone who had attempted suicide, 48 of them knowing someone who had thereby died. The contact with a non‐fatal suicide attempted by others was associated with own self‐harm (OR 1.73, CI 1.39–21.4, p<0.01); contact with completed suicide had no such association. The most important factor that increased the chance of knowing a suicide attempter was actual length of time spent in prison up to the time of the study; 95 (63%) of the young men with such contact had it in prison. No other significant vulnerability factors were identified.It seems likely that imprisonment is a specific vulnerability factor for self‐harm, one explanation being that it increases the risk of exposure to a contact with suicidal behaviour by others. Further work is called for to test relationships between such exposure and own behaviour over time, and to gather first hand accounts from the young men in such circumstances in order to understand the meaning for them of the contact with suicidal behaviour by others. This would inform appropriate intervention strategies, and could save much morbidity, and even mortality.
Gender issues in family poultry production systems in low-income food-deficit countries
Authors: Guèye E.F. 
Published: December 2003

AbstractDespite efforts to develop intensive poultry production, family poultry (FP) is still very important in low-income, food-deficit countries (LIFDCs). In LIFDCs, the keeping of poultry by local communities has been practiced for many generations. FP is an appropriate system for supplying the fast-growing human population with high-quality protein. It can also provide additional income to the generally resource-poor small farmers, especially women. Although requiring low levels of inputs, FP contributes significantly to food security, poverty alleviation and ecologically sound management of natural resources. FP is also a source of employment for underprivileged groups and less-favored areas in LIFDCs. Developing schemes that aim to promote and improve the FP sub-sector in a way that is sustainable must not underestimate the roles and contributions of women. However, getting new information to the front line of production requires more gender-disaggregated data. This paper stresses the need to design, implement, monitor and evaluate FP development programs by taking into account socio-cultural, especially gender, issues.
What Caused the Asian Crises: An Early Warning System Approach
Authors: Berg A. , Pattillo C. 
Published: December 2003

We estimate a simple probit model of the probability of balance‐of‐payments crises over a panel of developing countries through 1995. We then forecast crisis probabilities for 1997. We find that a simple model composed of four traditional macroeconomic variables and one ‘second generation’ variable performs well in predicting the Asia crises. The Thai and Malaysian crises had predominantly first‐generation features, while the crises in Korea and Indonesia are, to some extent, predictable largely on the basis of our second‐generation variable.(J.E.L.: F31, F47).
Solving the Currency Conundrum
Authors: Eichengreen Barry 
Published: December 2003

This paper reviews the prospects for the exchange rate system in different parts of the world. It discounts radical changes like a single world currency and a trio of regional monetary unions: in Europe, where intergration is political as well as economic and financial, the euro should provide the basis for an expanding zone of monetary stability; in the Americas, in contrast, dollarization is likely to be the solution for countries with strong financial links to the USA that find it difficult to run an autonomous monetary policy; and in Asia, continued floating is the only plausible outcome, given the obstacles to the alternatives.(J.E.L.: F3)
Monetary Disequilibrium, Endogenous Money, Stability and the Determinacy of Inflation
Authors: Chappell David , Matthews Kent 
Published: December 2003

This paper examines the stability of the disequilibrium money model, with endogenous money and transitory interest rate control by the Central Bank. In the tradition of the post‐Keynesian literature, the money supply is determined by bank lending and disequilibrium between money demand and supply determines the business cycle. The rate of interest is assumed to react to an inflation target and inflation responds to the business cycle. The paper examines the stability of the model under three inflation response systems: the accelerationist model, adaptive expectations and rational expectations.(J.E.L.: E3, E4, E5).
The New Basel Capital Adequacy Framework
Authors: Carosio Giovanni 
Published: December 2003

The Basel Committee on Banking Supervision is about to publish a second consultative paper on the reform of the 1988 Accord on capital adequacy. The new document takes into account the comments received on the June 1999 consultative paper, gives a much clearer picture of crucial aspects of the reform that were only presented in very general terms in the earlier paper, and quantifies most of the parameters that will be needed to calculate the capital requirements.Although considerable progress has been made towards reaching operational status, several aspects of the regulation still need to be worked out and further reflection is needed on the best way to tackle some of the more problematic issues that have been identified. Comments, suggestions, criticisms such as today’s seminar will certainly provide, are therefore most welcome. There will be time to take them into consideration, as the final draft of the regulation will not be completed before the end of 2001.My presentation is divided into three parts: I first illustrate the objectives of the reform, then describe the essential features of the new regulation, and finally discuss the possible impacts of its implementation.(J.E.L. G21, G28).