bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydride Route for the Palladium‐Catalysed Cyclocarbonylation of Monoterpenes
Authors: Nguyen Duc Hanh , Laurenczy Gábor , Urrutigoïty Martine , Kalck Philippe 
Published: September 2005

AbstractThis paper focuses on the mechanism by which a monoterpene undergoes a cyclocarbonylation reaction catalysed by a palladium complex. Evidence is provided, based on intermediate species observed under pressure or with various ligands, that the catalytic cycle follows a hydride route starting from [Pd(H)(SnCl3)L2]. The [Pd(H)(SnCl3)L2] complexes (L = PPh3 or PCy3) have been observed for the first time by multinuclear NMR spectroscopy. Cationic hydride complexes or palladium(0) precursors show either no or poor reactivity. Studies related to model platinum complex chemistry have detected an acylplatinum species. Most of the observations have been done on the cyclocarbonylation of isopulegol, dihydromyrcenol or isolimonene into the corresponding lactones or cyclopentanones. The use of dihydromyrcene allowed us to observe the acylplatinum complex and the corresponding elusive acylpalladium species. The co‐catalytic role of SnCl2 is also demonstrated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Multiple Regulated Assembly, Crystal Structures and Magnetic Properties of Porous Coordination Polymers with Flexible Ligands
Authors: Sun Chang‐Yan , Zheng Xiang‐Jun , Gao Song , Li Li‐Cun , Jin Lin‐Pei 
Published: September 2005

AbstractFour novel coordination polymers of NiII and CoII with flexible ligands, namely [Ni(oba)(bpe)]n·nH2O (1), [Co(oba)(bpe)]n (2), [Ni2(oba)2(bpy)2(H2O)2]n·nbpy (3), and [Co(oba)(bpy)1/2]n (4) [H2oba = 4,4′‐oxybis(benzoic acid), bpe = 1,2‐bis(4‐pyridyl)ethane, bpy = 4,4′‐bipyridine] were synthesised by hydrothermal reactions and characterised by single‐crystal X‐ray diffraction, elemental analysis and IR spectroscopy. The NiII ions in complex 1 are linked by flexible oba and bpe ligands to form square‐grid‐like corrugated sheets. These sheets are interpenetrated with each other, resulting in the formation of a 3D porous network with lattice water molecules in the channels. The variable temperature X‐ray diffraction analysis shows that the framework is stable up to 300 °C despite the complete removal of the lattice water molecules during the heat treatment. Complex 2 can be regarded as possessing a α‐polonium‐related topology. Triple interpenetration occurs to form a nonporous structure. In complex 3, the oba and bpy ligands link NiII ions into 1D train‐like boxes. These boxes are entangled, with the aid of hydrogen bonds, leading to the formation of a 3D porous supramolecular architecture. Free bpy ligands reside in the channels. The CoII ions in complex 4 are linked by oba and bpy ligands to form a complicated 3D coordination polymer. The lattice water molecules in complex 1 and free bpy ligands in complex 3 can be regarded as templates that play an important role in the formation of the porous structures of complexes 1 and 3. The magnetic properties of complexes 1, 2, and 4 have also been investigated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
On the Borderline between cis and trans in Organometallic(Phosphane)platinum(II) Complexes
Authors: Gudat Dietrich , Jain Vimal K. , Klein Axel , Schurr Thilo , Záliš Stanislav 
Published: September 2005

AbstractThe borderline between the cis and trans configurations in square‐planar diarylplatinum(II) complexes with triethylphosphane ligands [Pt(Ar)2(PEt3)2] [Ar = 2,4,6‐trimethylphenyl (mesityl), 2,6‐dimethylphenyl, 2‐methylphenyl, 3‐methylphenyl, 4‐methylphenyl and phenyl] has been investigated by a combination of multinuclear (1H, 13C, 31P and 195Pt) NMR spectroscopy, X‐ray crystallography and quantum chemical (DFT) calculations. When formed under thermodynamic conditions, the complexes show a clear cut‐off between cis (tolyl and phenyl complexes) and trans (2,6‐xylyl and mesityl complexes). The syn and anti stereoisomers were identified for the 2‐methylphenyl and 3‐methylphenyl derivatives. Calculated data (structural isomers or NMR) are in excellent agreement with experimental findings. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Supramolecular Arrangement of C60 and Phenol into a Square Packing Arrangement of π‐π Interacting and Hydrogen‐Bonded Rods in C60·5C6H5OH
Authors: Schulz‐Dobrick Martin , Panthöfer Martin , Jansen Martin 
Published: September 2005

AbstractThe supramolecular adduct C60·5C6H5OH was obtained as single crystals by the slow hydrolysis of a solution of C60 in triphenylphosphite. The crystal structure was determined with atomic resolution by single‐crystal X‐ray diffraction [triclinic, space group P$\tilde {1}$, a = 1003.52(14) pm, b = 1011.71(14) pm, c = 1264.17(17) pm, α = 88.566(2) °, β = 84.026(2) °, γ = 83.485(2) °, V = 1.2681(3) nm3, Z = 1]. The overall structure can be described as a distorted square packing pattern of hydrogen‐bonded and π‐π interacting rods,1∞[C60(C6H5OH)4]. The fullerene molecules are fully ordered and the C–C bond lengths exhibit remarkably small variations within the 6:6 and 6:5 subsets. The results are discussed in the context of an analysis of reliable crystal structure data for several different fullerene co‐crystal compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
The Influence of the Neutral Coligand on the Spectroscopic Properties and Crystal Structures of Lithium Tri(tert‐butyl)silylarsanides of the Type[(L)LiAs(H)SitBu3] (L = DME, THF)
Authors: Westerhausen Matthias , Krofta Mathias , Mayer Peter , Piotrowski Holger 
Published: September 2005

AbstractThe reaction of [(dme)LiAsH2] with F3CSO3SitBu3 yields tri(tert‐butyl)silylarsane (1). The reaction of 1 with n‐butyllithium in 1,2‐dimethoxyethane gives [(dme)LiAs(H)SitBu3]2 (2), whereas the lithiation of 1 in THF leads to the formation of the one‐dimensional polymer [(THF)LiAs(H)SitBu3]∞ (3). The Li–As bond lengths of both of these compounds show a similar value of approximately 260 pm. However, the smaller coordination number of the lithium atom in 3 leads to a short Li–O distance of 190 pm, whereas in 2, which has a tetracoordinate lithium atom, an average bond length of 199 pm is observed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis, Structure and Photoluminescent Studies of Two Novel Layered Uranium Coordination Polymers Constructed from UO(OH) Polyhedra and Pyridinedicarboxylates
Authors: Zheng Yan‐Zhen , Tong Ming‐Liang , Chen Xiao‐Ming 
Published: September 2005

AbstractTwo new uranium coordination polymers have been obtained from the hydrothermal reaction of (UO2)(CH3COO)2·2H2O with 3,4‐pyridinedicarboxylic acid (3,4‐pydaH2) or 2,4‐pyridinedicarboxylic acid (2,4‐pydaH2). [(UO2)3(μ3‐O)(μ3‐OH)2(3,4‐pydaH)(3,4‐pyda)0.5]n (1) crystallizes in the orthorhombic space group Pccn with a = 18.168(2), b = 12.635(1), c = 16.149(1) Å, V = 3707.0(5) Å3, and Z = 8. [(UO2)3(μ3‐O)(μ3‐OH)(μ2‐OH)(2,4‐pyda)(H2O)2]n·nH2O (2) is in the orthorhombic space group Pbcn with a = 22.788(2), b = 7.1468(5), c = 21.627(1) Å, V = 3522.1(4) Å3, and Z = 8. Complex 1 features a wave‐like 2D layer that is constructed by connecting the 1D UO(OH) ribbons by the V‐shaped 3,4‐pyda or 3,4‐pydaH ligands. Complex 2 is a rare hexameric species amongst uranium compounds and features a (4,4) planar “open‐layer”, which is constructed by the 4‐connected hexameric UO(OH) polyhedra and the 2‐connected 2,4‐pyda ligands. The fluorescence emission (521 nm) of 2 is red‐shifted by about 13 nm (emission) and about 40 nm (excitation) compared to that of 1, and the lifetimes increase with the polymerization of UO(OH) polyhedra (145 μs for 1 compared to 24.4 μs for 2). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Vibrational Spectra of Eight‐Coordinate Niobium and Tantalum Complexes with Peroxo Ligands: A Theoretical Simulation
Authors: Bayot Daisy , Devillers Michel , Peeters Daniel 
Published: September 2005

AbstractA theoretical interpretation of the experimental observations made by vibrational IR and Raman spectroscopy on eight‐coordinate peroxo complexes of niobium(V) and tantalum(V) is carried out. The theoretical study, realised on stoichiometric models of general formula [M(O2)4]3–, [M(O2)3L2]x–, cis‐ and trans‐[M(O2)2L4]y– and [M(O2)L6]z– (M = NbV or TaV), provides the normal modes of vibrations involving peroxo ligands, their corresponding calculated frequency and their activity in IR and/or Raman spectroscopy. The theoretical results from the model complexes are compared with experimental IR and Raman spectroscopic data. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
B‐Substituted (Arene)ruthenacarborane–Sulfonium, –Thioether and–Mercaptan Complexes: Mild Single and Double Dealkylation and Structural Implications in the Antipodal Distance
Authors: Planas José Giner , Viñas Clara , Teixidor Francesc , Light Mark E. , Hursthouse Michael B. , Ogilvie Helen R. 
Published: September 2005

AbstractReactions of [RuCl2(η6‐arene)]2 (arene = benzene, p‐cymene) with nido‐[7‐R‐10‐L‐7,8‐C2B9H9]– in THF at room temperature for 3 d give the (arene)ruthenacarborane complexes closo‐[3‐Ru(η6‐arene)‐1‐R‐8‐L‐1,2‐C2B9H9]+ {arene = benzene, R = H [L = Me2S (1a), THT (1b), EtPhS (1c)], R = Me [L = Me2S (2a)]; arene = p‐cymene, R = H [L = Me2S (3a)]} and mercaptan closo‐[3‐Ru(η6‐arene)‐1‐R‐8‐HS‐1,2‐C2B9H9] [arene = benzene, R = H (4), Me (5); arene = p‐cymene, R = H (6)] in yields of 20–40 % and 22–29 %, respectively. The asymmetric ligand nido‐[9‐Me2S‐7,8‐C2B9H10]– leads to the thioether complex closo‐[3‐Ru(η6‐benzene)‐7‐MeS‐1,2‐C2B9H10] (8) in 34 % yield under the same reaction conditions. The crystal structure of 1a is described and compared with those of 4 and 8. The fully assigned 11B NMR spectroscopic data for a whole series of ruthenacarboranes having B‐substituted sulfonium, thioether and mercaptan groups are presented. These data show a relation between antipodal cluster atom distances (antipodal distance) and antipodal effect (AE) in the crystal structures of these complexes and for other families of heteroboranes such as closo‐[EB11H11] and closo‐[EB9H9]. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Triazenes by Acid‐Mediated Opening of the Dihydro‐1,2,3‐triazole Ring of1,3‐Dipolar Cycloadducts of Organic Azides to Cyclic Ketene N,N‐Acetals
Authors: Quast Helmut , Ach Manfred , Regnat Dieter 
Published: September 2005

AbstractSpirocyclic 1,3‐dipolar cycloadducts 1 and 4 of azides to heterocyclic ketene N,N‐acetals open their dihydro‐1,2,3‐triazole ring in the presence of weak Brønsted acids to afford novel 1,3‐substituted triazenes 2X and 5X, respectively, which form colorless, crystallized tetrafluoroborates (X = BF4) and hexafluorophosphates (X = PF6). Ring‐opening is reversed in alkaline solutions. Methyl triflate methylates the dihydro‐1,2,3‐triazole ring of 1a and 4 at N‐3 and thus induces ring‐cleavage to 1,3,3‐trialkyltriazenes 3 and 6, respectively. The 1,3‐substituted triazenes 2aX, 2bBF4, 2dX and 5X exist as tautomers that have the larger substituents, which include the heterocyclic rings, connected with the azo group (N‐1). By contrast, triazene 2cPF6 has a bulky alkyl group at each terminal nitrogen and hence forms two rapidly equilibrating tautomers of similar stability. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Self‐power associations: the possession of power impacts women's self‐concepts
Authors: Haines Elizabeth L. , Kray Laura J. 
Published: September 2005

AbstractWomen's self‐identification with social power was assessed in three studies using the Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998). In Experiment 1, women held weaker implicit and explicit associations between self and power than did men. Experiment 2 demonstrated that women assigned to a high power group have stronger implicit self‐power associations than do women in a low power group. Experiment 3 showed that women assigned to a high power role have stronger implicit self‐masculine associations than do women assigned to a low power role, but social power did not affect explicit associations with masculinity. These studies suggest that gender differences in implicit self‐concept may be malleable depending on context and social roles. Copyright © 2005 John Wiley & Sons, Ltd.
Don't ignore the other half: the impact of ingroup identification on implicit measures of prejudice
Authors: Sassenberg Kai , Wieber Frank 
Published: September 2005

AbstractRecently several implicit measures of prejudice have been developed. Prejudice indices based on these measures are computed from response differences to positive and negative targets resulting from outgroup compared to ingroup stimuli. Up to now the focus of research involving these measures has mainly been on attitudes and relations to outgroups (i.e. negative attitudes towards the outgroup). It is suggested here that implicit measures of prejudice are also influenced by one's relation towards the ingroup (i.e. ingroup identification), because they involve ingroup as well as outgroup stimuli. A correlational study and an experiment were conducted that supported this prediction. Implications for the application of implicit measures are discussed. Copyright © 2005 John Wiley & Sons, Ltd.
The burden of benevolent sexism: how it contributes to the maintenance of gender inequalities
Authors: Barreto Manuela , Ellemers Naomi 
Published: September 2005

AbstractThis study (N = 235) examines the responses of male and female participants to information about the alleged endorsement of either hostile or benevolent sexist beliefs by a sample of either men or women. We predicted that people endorsing benevolent sexist statements would be less likely to be perceived as sexist than those endorsing hostile sexist views, and examined the judgmental process through which people fail to recognize benevolent sexism as a form of prejudice. We argue that benevolent sexists do not match the mental prototype of sexist perpetrators, because they are seen as likeable. Our results confirm that because benevolent sexists are evaluated more positively than hostile sexists, they are less likely to be seen as sexists. This judgmental process occurs relatively independently of emotional responses to hostile vs. benevolent sexism. These results are discussed in terms of their relevance to the maintenance of gender inequalities. Copyright © 2005 John Wiley & Sons, Ltd.
When differences matter: intergroup distinctiveness and the evaluation of impostors
Authors: Jetten Jolanda , Summerville Natasha , Hornsey Matthew J. , Mewse Avril J. 
Published: September 2005

AbstractThe present study examined the effect of intergroup distinctiveness and group membership on evaluations of impostors. We predicted that ingroup members would be harsher than outgroup members on an impostor and that perceptions of intergroup distinctiveness would further moderate these evaluations. Specifically, we tested the social identity theory prediction that low intergroup distinctiveness would lead to greater derogation of the impostor (the ‘reactive distinctiveness’ hypothesis) against the self‐categorization hypothesis that high intergroup distinctiveness would instigate more derogation of an impostor (the ‘reflective distinctiveness’ hypothesis). In this study, vegetarians (ingroup members) and meat eaters (outgroup members) were presented with a target claiming to be vegetarian, but caught indulging in a meat dish. We found that ingroup members derogated the impostor more and felt less pleased about discovering the impostor behaviour than did outgroup members. In line with the reflective distinctiveness hypothesis, the heightened derogation displayed by ingroup members only emerged when intergroup distinctiveness was high, an effect that was mediated by ratings of group identification. The discussion focuses on the different responses intergroup distinctiveness may evoke. Copyright © 2005 John Wiley & Sons, Ltd.
Responses to verifying and enhancing appraisals from romantic partners: the role of trait importance and trait visibility
Authors: Campbell Lorne 
Published: September 2005

AbstractAn experiment assessed when people respond more positively to verifying and enhancing appraisals from romantic partners. Two‐hundred and fifty‐eight individuals comprising 129 dating couples participated in this research. Couples privately rated their self‐concept on traits that were either high or low on trait visibility, rated how important each trait was to them, and rated their partners. A computer program ostensibly compared their self‐ratings with appraisals from their partners on traits they selected as being high or low in personal importance, and participants received either verifying or enhancing feedback. Confirming predictions, people believed their partners understood them more when they received verifying feedback, but felt their partners saw the best in them when they received enhancing feedback. Additionally, people responded more positively to verifying appraisals on important, less visible traits, and enhancing appraisals on important, highly visible traits. Results are discussed in terms of preferences for enhancing and verifying feedback in romantic relationships. Copyright © 2005 John Wiley & Sons, Ltd.
Experimentally manipulated high in‐group status can buffer personal self‐esteem against discrimination
Authors: Platow Michael J. , Byrne Leanne , Ryan Michelle K. 
Published: September 2005

AbstractWe present an experiment in which the relative status of an in‐group and the discriminatory nature of a decision maker's intergroup behaviour (in‐group‐favouring/out‐group‐favouring/even‐handed) were independently manipulated to observe their effects on self‐esteem. Adopting a Social Identity Theory framework, and following from previous empirical work, we predicted that discrimination against one's in‐group would lead to lower self‐esteem among members of a low‐status group but not among members of a high‐status group. This prediction was confirmed. Copyright © 2005 John Wiley & Sons, Ltd.
Capillary electrophoresis in N,N‐dimethylformamide
Authors: Porras Simo P. , Kenndler Ernst 
Published: September 2005

AbstractN,N‐Dimethylformamide (DMF) is a dipolar protophilic solvent with physicochemical properties that makes it suitable as solvent for capillary electrophoresis (CE). It is prerequisite for the proper application of CE to adjust and to change the pH of the background electrolyte (BGE) in a defined manner. This was done in the present work using benzoic acid‐benzoate by selecting different concentration ratios of acid and salt, and calculating the theoretical pH from the activity‐corrected Henderson–Hasselbalch equation. The mobilities of the analytes (chloro‐ and nitro‐substituted phenolates) were found to follow reasonably well the typical sigmoid mobility versus pH curve as predicted by theory. The actual mobilities and pKa values (at 25°C) of the analytes were derived from these curves. pKa values were in the range of 11.1–11.7, being thus 3–4.4 units higher than in water. This pKa shift is caused by the destabilization of the analyte anion and the better stability (solubility) of the molecular analyte acid in DMF, which overcome the higher basicity of DMF compared to water. Absolute mobilities were calculated from the actual mobilities; they were between 32×10−9 and 42×10−9 m2/V×s. Slight deviations of the measured mobilities from the theoretical mobility versus pH curve were discussed on the bases of ion pairing and heteroconjugation and homoconjugation of either buffer components or buffer components and analytes. Heteroconjugation was used as a mechanism for the electrically driven separation of neutral analyte molecules in a BGE where salicylate acted as complex forming ion. Rough estimation of the complexation constants for the phenolic analytes gave values in the range of 100–200 L/mol. Addition of water to the solvent decreased the effect of heteroconjugation, but it was still present up to the surprisingly high concentration of 20% water. Electrophoretically relevant parameters like ionic mobilities and pKa values, and conjugation and ion pairing are dependent on the water content of the solvent. The water uptake of DMF was measured when exposed to humidity of ambient air. The resulted behavior of the water uptake was found rather similar to that for acetonitrile and methanol.
Study on sensitivity development of 2,3‐dihydroxybenzoic acid by capillary zone electrophoresis–amperometric detection with p‐methyl benzoate as stacking agent
Authors: Wang Qingjiang , Chen Xiang , Lu Jin , He Pingang , Fang Yuzhi 
Published: September 2005

AbstractFor its high reactivity and very short half‐life, the hydroxyl radical (OH·) in vivo is very difficult to be detected. Usually, it is indirectly quantified by determining 2,3‐dihydroxybenzoic acid (2,3‐DHBA) and 2,5‐dihydroxybenzoic acid (2,5‐DHBA), which are the reaction products of salicylic acid (SA) and OH·. Because 2,5‐DHBA could be directly formed by the P450 enzyme, only 2,3‐DHBA is regarded as the real biomarker of OH·in biological studies. But the very low concentration of OH· in human bodies makes its determination very difficult and complicated. In this paper, a simple online stacking capillary zone electrophoresis coupled with amperometric detection (CZE‐AD) method was explored to improve the detection sensitivity of 2,3‐DHBA to reach the requirements in biological analysis. A mixture solution of 12.5 mmol/L Na2B4O7–25 mmol/L NaH2PO4 (pH 7.9) was used as the running buffer and p‐methyl benzoate was selected as a suitable stacker. The effects of the concentration, pH value, and injection time of p‐methyl benzoate on stacking efficiency were carefully studied. Under the optimum stacking CZE‐AD conditions, the detection sensitivity of 2,3‐DHBA was improved about 20‐fold and its detection limit reached the 10−9 mol/L level. The experimental results showed that this was a potential method to determine OH· in vivo.
Aptamer–oligonucleotide binding studied by capillary electrophoresis: Cation effect and separation efficiency
Authors: André Claire , Xicluna Alain , Guillaume Yves‐Claude 
Published: September 2005

AbstractNovel features of DNA structure, recognition and discrimination have been recently elucidated through the solution structural characterization of DNA aptamers that bind cofactors, amino acids and peptides with high affinity and specificity. Multidimensional nuclear magnetic resonance methodologies have been successfully applied to solve the solution structures. In this work, it was demonstrated that capillary electrophoresis was a powerful tool allowing the fundamental study of the binding mechanism between a DNA aptamer and three ligands, adenosine and adenylate compounds, i.e., adenosine diphosphate (ADP) and adenosine triphosphate (ATP). In order to gain further insight into this binding, thermodynamic measurements under different values of parameters (such as salt nature and its concentration (x) in the run buffer) were carried out. The results showed that dehydration at the binding interface, van der Waals interactions, H‐bonding and adjustment of the aptamer recognition surface were implied in the aptamer–ligand association. As well, it was demonstrated that the addition in the medium of the sodium monovalent cation Na+ or the nickel divalent cation Ni2+ decreased the complex formation. Separation efficiency and peak shape can also be improved by Mg2+ divalent cation, which increased the mass transfer kinetics during the ligand–aptamer binding process. A significant separation for the worst separated pair of peaks on the electropherogram ((ADP, ATP) peak pair) was thus achieved.