bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tricarbonyl Derivatives of Manganese(I) with Diphosphinite Chelating Ligands
Authors: Bravo Jorge , Castro Jesús A. , Freijanes Eduardo , García–Fontán Soledad , Lamas Elvira M. , Rodríguez‐Seoane Pilar 
Published: August 2005

AbstractReaction of [MnBr(CO)3L] [L = Ph2POCH2CH2OPPh2, L1, {(CH3)2CH}2POCH2CH2OP{CH(CH3)2}2, L2] with AgO3SCF3 and AgO2CCF3 in dichloromethane afforded the new complexes [Mn(O3SCF3)(CO)3L] and [Mn(O2CCF3)(CO)3L], respectively. Substitution of O3SCF3 resulted in the new species [Mn(SCN)(CO)3L], [Mn(NCCH3)(CO)3L](O3SCF3) and, in the case of L2, [Mn(CN)(CO)3L2]. By contrast, any attempt to displace the O2CCF3 ligand in the same way was unsuccessful. After maintaining for some days the complex [Mn(CH3CN)(CO)3L1](O3SCF3) in dichloromethane at room temperature, the new complex [MnCl(CO)3L1] was formed. All the new complexes were characterized by elemental analysis, mass spectrometry and IR and NMR spectroscopies. In the case of [Mn(O3SCF3)(CO)3L1], [Mn(O2CCF3) (CO)3L1], [MnCl(CO)3L1], [Mn(CH3CN) (CO)3L2] (O3SCF3), [Mn(CN)(CO)3L2] and [Mn(O2CCF3)(CO)3L2], together with the previously synthesized complex [MnBr(CO)3L2], suitable crystals for X‐ray structural analysis were isolated. In all of them the Mn atom adopts six‐coordination by bonding to the three CO ligands, the two P atoms of L and either one C atom (CN), one oxygen atom (O2CCF3, O3SCF3), one N atom (CH3CN, SCN) or the halogen atom (Cl, Br).
High Pressure Synthesis and Characterization of New Members of the RuSr2(RE, Ce)2Cu2O10 Family (RE = Y, Dy)
Authors: Gallardo‐Amores José Manuel , Martínez José Luis , Morán Emilio 
Published: August 2005

AbstractNew members of the RuSr2(RE2−x, Cex)Cu2O10 family of magnetically ordered phases have been synthesized under high pressure / high temperature conditions for RE = Y (x = 0.5, 0.7) and Dy (x = 0.5). All compounds show tetragonal symmetry with cell parameters a ≈ 3.82 Å and c ≈ 28.4 Å. Magnetic susceptibility vs temperature measurements show ferromagnetic behaviour of these compounds with TM = 120–140 K, depending on Ce content. These compounds are semiconducting and tend to transform into insulator, by increasing Ce content, as observed by the temperature dependence of the resistance.
Synthesis, Crystal Structure and Magnetic Properties of [Fe(bpe)4(H2O)2](TCNQ)2 (bpe = trans‐1,2‐bis(4‐pyridyl)ethane and TCNQ = tetracyanoquinodimethane)
Authors: Galet Ana , Muñoz M. Carmen , Agustí Gloria , Martínez Víctor , Gaspar Ana B. , Real José Antonio 
Published: August 2005

AbstractThe synthesis, structure and magnetic properties of [Fe(bpe)4(H2O)2](TCNQ)2 (1) are reported. 1 crystallizes in the triclinic P$\bar{1}$ space group, a = 13.481(5), b = 14.887(3), c = 16.663(4) Å, α = 101.048(18), β = 112.84(2), γ = 90.92(2)°, V = 3009.6(14) Å3, Z = 2. The iron atom defines a compressed octahedron with the equatorial positions occupied by the bpe molecules which act as monodentate ligands and the two axial positions occupied by water molecules. The TCNQ− radical counterions are uncoordinated and interact by pairs defining (TCNQ)22− units strongly coupled antiferromagnetically. The iron(II) atoms are in the high spin state and its magnetic behaviour indicates the occurrence of zero‐field splitting of the S = 2 ground state.
Crystal Structure of the Ordered Double Perovskite, Sr2NiTeO6
Authors: Martín L. Ortega‐San , Chapman J. P. , Cuello G. , González‐Calbet J. , Arriortua M. I. , Rojo T. 
Published: August 2005

AbstractThe crystal structure of the ordered double perovskite Sr2MnTeO6 has been refined at ambient temperature from high resolution neutron and X‐ray powder diffraction data in the monoclinic space group I 1 2/m 1 with a = 5.6166(1) Å, b = 5.5807(1) Å, c = 7.8797(1) Å and β = 90.048(2)°. The structure is the result of out‐of‐phase (–) rotations of virtually undistorted NiO6 and TeO6 octahedra in the (0 – –) sense about two of the axes of the ideal cubic perovskite. Electron diffraction measurements have been used to confirm the proposed space group and structure.
Synthesis and Characterization of a H+ Exchanged Zirconate
Authors: Orera A. , Kuhn A. , Alvarado F. García 
Published: August 2005

AbstractA new protonated oxide has been synthesized by ion exchange of lithium by proton in lithium metazirconate, Li2ZrO3. Easy and complete ion exchange has been achieved in acidic medium. Characterization of the protonated solid by means of X–ray powder diffraction and thermogravimetric analysis allow to propose the nominal formulation “H2ZrO3”. However vibrational spectroscopy suggests that a more appropriate formulation would be as an oxyhydroxide ZrO(OH)2.
Synthesis and Characterization of Pyrrolthiosemicarbazone Complexes of Palladium(II). Crystal Structures of [{Pd[C4H4NC(H)=NNC(S)NHMe](Cl)}2{μ‐Ph2P(CH2)3PPh2}] and[Pd{C4H4NC(H)=NNC(S)NHMe}{Ph2P(CH2)2PPh2‐P, P}](Cl)
Authors: Adrio Luis , Alberdi Gemma , Amoedo Adriana , Lata Darío , Fernández Alberto , Martínez Javier , Pereira M. Teresa , Vila José M. 
Published: August 2005

AbstractReaction of the thiosemicarbazone ligands C4H4NC(H)=NN(H)C(S)NHR (R = Me, a; Et, b) with Li2[PdCl4] gave the dinuclear complexes [Pd{C4H4NC(H)=NNC(S)NHR}(μ‐Cl)]2 (R = Me, 1a; Et, 1b) with a central Pd2Cl2 core and with deprotonation of the thiosemicarbazones at the hydrazinic nitrogen atom. Treatment of 1a and 1b with triphenylphosphine gave the mononuclear compounds [Pd{C4H4C(H)=NNC(S)NHR}(Cl)(PPh3)] (R = Me, 2a; Et, 2b), whereas reaction of 1a and 1b with tertiary diphosphines gave mono‐ and dinuclear compounds, as appropriate, with the corresponding diphosphine acting as a monodentate (6b), chelating (3a) and bridging ligand (4a, 5a, 4b, 5b). Treatment of 1a and 1b with (Ph2PCH2CH2PPh2)W(CO)5 gave the new heterobimetallic complexes 7a and 7b. The crystal structures of complexes 3a and 4a are described.
Synthesis, Characterization and Magnetic Properties of New Dinuclear Copper(II) Complexes with N,N′‐Disubstituted Dithiooxamides derived from α‐Amino Acids
Authors: Borrás J. , Carballo R. , Castiñeiras A. , Gómez‐Conde M. C. , Fernández‐Vidal M. C. , Niclós J. 
Published: August 2005

AbstractFour new dinuclear copper(II) complexes have been synthesized and have the general formula [Cu2(L)(H2O)2], where L = GLYDTO [N,N′‐bis(carboxymethyl)dithiooxamide], ALADTO [N,N′‐bis(carboxyethyl)dithiooxamide], VALDTO [N,N′‐bis(1‐carboxy‐2‐methylpropyl)dithiooxamide] and LEUDTO [N,N′‐bis(1‐carboxy‐3‐methylbutyl)dithiooxamide]. The complexes were characterized by elemental analysis as well as by IR, electronic and EPR spectroscopy. These techniques provided evidence for the presence of the CuNO2S chromophore. Magnetic susceptibility measurements on all the complexes in the range 4–300 K show the existence of a dominant antiferromagnetic interaction with −J values greater than 300 cm−1. Thermal decomposition behaviour of the complexes was studied by thermogravimetry.
A Direct Amination of Isoprene by Aniline – Catalyzed by Palladium Complexes
Authors: Petrushkina E.A. , Mysova N. E. , Orlinkov A. V. 
Published: August 2005

AbstractThe reaction of isoprene with aniline, catalyzed by Pd (acac)2–(RO)3P‐CF3COOH, (1:4:4) (R = Me, Et, acac = (CH3CO)2CH‐) in MeCN solution, results in high (up to 89 mol.%) selectivity of N–(3‐methyl‐2‐buten‐1‐yl) aniline. The presence of telomeric products in the reaction mixture is observed at a P/Pd ratio of 1:2 and 1:1. The use of (1,1,1‐trifluoro, 4‐perfluorocyclo hexyl ‐2,4‐butanedionato) palladium as the catalyst gives rise to 92 mol% mol.selectivity of telomers by the favored tail‐to‐head and head to head coupling.
Study of the Interaction of Bis(4‐pyridylthio)methane with Copper(II) Chloride and Bromide
Authors: Amoedo‐Portela Almudena , Carballo Rosa , Casas José S. , García‐Martínez Emilia , Lago‐Blanco Ana B. , Sánchez‐González Angeles , Sordo José , Vázquez‐López Ezequiel M. 
Published: August 2005

AbstractThe new ligand bis(4‐pyridylthio)methane (4‐bpytm) (1) and its complexes [CuX2(4‐bpytm)] and [CuX2(4‐bpytm)2] (X = Cl and Br) (2 – 5) have been prepared and characterized by elemental analysis, IR‐Raman, UV/Vis spectroscopy. The structures of (4‐bpytm) (1), [CuCl2(4‐bpytm)2] (3) and [CuBr2(4‐bpytm)2] (4) were determined by single‐crystal X‐ray diffraction analysis. X‐ray analysis of the 1:2 derivatives reveals that the copper atom has a distorted (4 + 2) octahedral environment. The copper atom is coordinated by four nitrogen atoms from four bridging 4‐bpytm ligands and two halogen atoms. The axial Cu–N bonds are considerably longer than the equatorial Cu–N bonds owing to JahñTeller distortion. CuX2 units are linked to each other through bridging 4‐bpytm ligands to form a 2D interpenetrated coordination polymer. The structural parameters of the 4‐bpytm ligand in these complexes were compared with those of the free ligand.
Molecular and Supramolecular Structures of 1‐Phenyl‐4‐phenylacetyl‐2‐thiosemicarbazide (H2L) and its Complexes with Diphenyllead(IV) Chloride and Acetate
Authors: Casas J. S. , Castellano E. E. , Ellena J. , García‐Tasende M. S. , Sánchez A. , Sordo J. , Touceda A. 
Published: August 2005

AbstractReaction of 1‐phenyl‐4‐phenylacetyl‐2‐thiosemicarbazide (H2L) with diphenyllead(IV) dichloride and acetate afforded the complexes [PbPh2Cl2(H2L)2] and [PbPh2L]. The ligand and the complexes were characterized by elemental analyses, 1H and 13C NMR spectroscopy and X‐ray crystallography. In the asymmetric unit of crystals of the ligand there are four independent molecules of H2L and four molecules of water, which associate in the lattice as two independent sheets. The complex [PbPh2Cl2(H2L)2]·4MeOH has slightly distorted all‐trans octahedral geometry around the lead atom, and the fact that the ligand is S‐bound rather than O‐bound suggests that PbPh2Cl2 behaves as a “soft” Lewis acid. Hydrogen bonds involving NH groups, Cl atoms and MeOH molecules form a three‐dimensional supramolecular structure. In [PbPh2L]·Me2CO, the L2− anion bridges between two metal centres, binding to one strongly via the N and S atoms and weakly via the O atom, and to the other via the O atom, thus creating polymeric chains along the b axis. The double deprotonation and metallation of H2L induce significant changes in its configuration and lengthen the C‐S and C‐O bonds, suggesting an evolution of the dianion towards a thiol‐enol form.
Study of the Dielectric Properties of the Perovskite LaMn0.5Co0.5O3–δ
Authors: Yáñez‐Vilar S. , Castro‐Couceiro A. , Rivas‐Murias B. , Fondado A. , Mira J. , Rivas J. , Señarís‐Rodríguez M. A. 
Published: August 2005

AbstractPolycrystalline samples of the charge ordered mixed oxide LaMn0.5Co0.5O3−δ (TCO = 400 K) have been prepared by the nitrate decomposition method. These samples are biphasic, according to XRPD, and except one, oxygen defficient (δ ≈ 0.04‐0.05). The study of the dielectric properties of these samples reveal that LaMn0.5Co0.5O3−δ displays a high dielectric constant, specially at room temperature and low frequencies. This ε′r is seen to be strongly dependent on the particle size and not so much on the oxygen defficiency and the best properties are found in the sample with biggest particle size (ϕ = 7 μm) for which ε′r (300 K) ≈ 105 up to 2x104 Hz. Analysis of the role of the grain size and the electrode contacts on the obtained data reveal that this mixed oxide has an intrinsic dielectric constant that is rather high for this type of compounds (ε′r,∞ ≈ 30) and that is further enhanced by extrinsic Maxwell‐Wagner effects. We relate such enhanced intrinsic dielectric constant to the electronic process of charge ordering present in this material below 400 K.
Metabolic gas kinetics depend upon the level of exercise performed
Authors: Witte Klaus K.A. , Thackray Simon D.R. , Lindsay Kenneth A. , Cleland John G.F. , Clark Andrew L. 
Published: August 2005

AbstractBackground:The kinetics of oxygen and carbon dioxide at the onset of and recovery from exercise are slowed in patients with chronic heart failure (CHF). The aim of the present study was to establish whether the kinetics of O2 are influenced by the work rate.Methods:Thirteen CHF patients and 12 control subjects underwent bicycle‐based peak exercise testing with metabolic gas exchange analysis. Each subject then exercised at 15%, 25% and 50% of the maximal workload achieved until reaching steady state. Time constants for onset (Tonset) and offset (Toffset) for O2 uptake and CO2 output were correlated to the workload and the percentage of peak performed during the steady state tests.Results:Patients had lower peak oxygen uptake () and the relation between ventilation and carbon dioxide output was steeper in patients than controls. Toffset for both oxygen (O2) and carbon dioxide (CO2) from peak exercise was significantly greater in the patients than the controls and correlated with peak (r=0.56, p<0.005 and r=0.58, p<0.005). Tonset and Toffset for o2 were increased in patients for each of the steady state tests and peak correlated with T for recovery of o2 (r=0.44; p<0.05 from 15%, r=0.35; p=<0.05 from 25%, and r=0.54; p<0.01 from 50%). There was a correlation between the Tonset (r=0.42; p<0.0005 for O2 and r=0.23; p<0.05 for CO2) and Toffset (r=0.49; p<0.0001 for O2 and r=0.42; p<0.0005 for CO2) and oxygen uptake as a percentage of peak exercise.Conclusions:This study demonstrates that the time constants of onset and offset for oxygen are dependent upon the degree of exertion performed relative to the individual's peak capacity.
Describing safe motherhood programs for priority setting: The case of Burkina Faso
Authors: Hounton S.H. , Meda N. , Hussein J. , Sombie I. , Conombo G. , Graham W.J. 
Published: August 2005

AbstractObjective: This study was implemented to describe safe motherhood programs in Burkina Faso for planning and programming purposes. Methods: Twenty safe motherhood programs were described from November 2003 through May 2004 using a structured questionnaire, interviews with safe motherhood program managers and document reviews. Results: Only 2 of the 20 programs were designed to improve the availability of comprehensive emergency obstetric care, and only 2 comprehensively addressed all components of skilled attendance at delivery. Other gaps identified included poor availability of baseline data, few monitoring measures, and lack of planning for evaluation needs. National geographical coverage was also uneven. Conclusion: A systematic overview of safe motherhood programs in a country can help to set priorities and aid in decision making for the allocation of resources towards contextually relevant strategies to curtail maternal mortality and severe morbidity. Planning for program design and evaluation may also be aided by such a process.
Hawthorne, Pearl, and the Primal Sin of Culture
Authors: BUDICK EMILY MILLER 
Published: August 2005

In his long critical essay entitled simply “Hawthorne” (published in 1879), Henry James narrates the story of his own coming to know Hawthorne's most famous work of fiction, The Scarlet Letter. Speaking in an impersonal third person, James, “who was a child at the time,” explains that heremembers dimly the sensation that book produced, and the little shudder with which people alluded to it, as if a peculiar horror were mixed in its attractions. He was too young to read it himself, but its title, upon which he fixed his eyes as the book lay upon the table, had a mysterious charm. … Of course it was difficult to explain to a child the significance of poor Hester Prynne's blood-coloured A. But the mystery was at last partly dispelled by his being taken to see a collection of pictures (the annual exhibition of the National Academy), where he encountered a representation of a pale, handsome woman, in a quaint black dress and white coif, holding between her knees an elfish-looking little girl, fantastically dressed and crowned with flowers. Embroidered on the woman's breast was a great crimson A, over which the child's fingers, as she glanced strangely out of the picture, were maliciously playing. I was told that this was Hester Prynne and little Pearl, and that when I grew older I might read their interesting history.
Forever Nearing the Finish Line: Heritage Policy and the Problem of Memory in Postwar Beirut
Authors: Fricke Adrienne 
Published: August 2005

Between 1976 and 1991, central Beirut, repository of centuries of historic structures, was substantially destroyed by civil war. In 1994, a private company known by its French acronym Solidère was created by government decree and given the task of reconstructing the center of Beirut. Despite political problems, the Solidère project brought the hope of social recovery through economic renewal; yet progress should not come at the cost of memory.How can Beirut, destroyed, be a site of both recovery and erasure? Even though traditional legal and political discourses acknowledge that cultural heritage holds a powerful position in reconstruction, there are few tools for capturing its functions. Using heuristics originally employed in archeology and art history, this article addresses psychological aspects of reconstruction by discussing contemporary Lebanese art. If culture is defined not only as what people do buthow they make sense of what they have done, the enormity of the political problems of post–civil war reconstruction become clear. National governments hoping to consolidate authority would do well to consider how best to approach public places resonant with emotionally charged memories.Policymakers should consider the complex benefits of negative heritage in drafting laws that will enable its protection. Legal reform carried out with the goal of balanced heritage policies that accommodate negative heritage is key for postconflict urban spaces. By acknowledging the weight of the past, such policies would also bolster confidence in the emergent government and the political process.
Leishmania major encodes an unusual peroxidase that is a close homologue of plant ascorbate peroxidase: a novel role of the transmembrane domain
Authors: Adak Subrata , Datta Alok K. 
Published: August 2005

Haem-containing enzymes (peroxidase and catalase) are widely distributed among prokaryotes and eukaryotes and play a vital role in H2O2 detoxification. But, to date, no haem-containing enzymatic defence against toxic H2O2 has been discovered in Leishmania species. We cloned, expressed and purified an unusual plant-like APX (ascorbate peroxidase) from Leishmania major (LmAPX) and characterized its catalytic parameters under steady-state conditions. Examination of its protein sequence indicated approx. 30–60% identity with other APXs. The N-terminal extension of LmAPX is characterized by a charged region followed by a stretch of 22 amino acids containing a transmembrane domain. To understand how the transmembrane domain influences the structure–function of LmAPX, we generated, purified and extensively characterized a variant that lacked the transmembrane domain. Eliminating the transmembrane domain had no impact on substrate-binding affinity but slowed down ascorbate oxidation and increased resistance to H2O2-dependent inactivation in the absence of electron donor by 480-fold. Spectral studies show that H2O2 can quickly oxidize the native enzyme to compound (II), which subsequently is reduced back to the native enzyme by an electron donor. In contrast, ascorbate-free transmembrane domain-containing enzyme did not react with H2O2, as revealed by the absence of compound (II) formation. Our findings suggest that the single copy LmAPX gene may play an important role in detoxification of H2O2 that is generated by endogenous processes and as a result of external influences such as the oxidative burst of infected host macrophages or during drug metabolism by Leishmania.
Isolation, subunit composition and interaction of the NDH-1 complexes from Thermosynechococcus elongatus BP-1
Authors: Zhang Pengpeng , Battchikova Natalia , Paakkarinen Virpi , Katoh Hirokazu , Iwai Masako , Ikeuchi Masahiko , Pakrasi Himadri B. , Ogawa Teruo , Aro Eva-Mari 
Published: August 2005

NDH (NADH-quinone oxidoreductase)-1 complexes in cyanobacteria have specific functions in respiration and cyclic electron flow as well as in active CO2 uptake. In order to isolate NDH-1 complexes and to study complex–complex interactions, several strains of Thermosynechococcus elongatus were constructed by adding a His-tag (histidine tag) to different subunits of NDH-1. Two strains with His-tag on CupA and NdhL were successfully used to isolate NDH-1 complexes by one-step Ni2+ column chromatography. BN (blue-native)/SDS/PAGE analysis of the proteins eluted from the Ni2+ column revealed the presence of three complexes with molecular masses of about 450, 300 and 190 kDa, which were identified by MS to be NDH-1L, NDH-1M and NDH-1S respectively, previously found in Synechocystis sp. PCC 6803. A larger complex of about 490 kDa was also isolated from the NdhL-His strain. This complex, designated ‘NDH-1MS’, was composed of NDH-1M and NDH-1S. NDH-1L complex was recovered from WT (wild-type) cells of T. elongatus by Ni2+ column chromatography. NdhF1 subunit present only in NDH-1L has a sequence of -HHDHHSHH- internally, which appears to have an affinity for the Ni2+ column. NDH-1S or NDH-1M was not recovered from WT cells by chromatography of this kind. The BN/SDS/PAGE analysis of membranes solubilized by a low concentration of detergent indicated the presence of abundant NDH-1MS, but not NDH-1M or NDH-1S. These results clearly demonstrated that NDH-1S is associated with NDH-1M in vivo.
NMR structural analysis of a peptide mimic of the bridging sheet of HIV-1 gp120 in methanol and water
Authors: Chakraborty Kausik , Shivakumar P. , Raghothama S. , Varadarajan Raghavan 
Published: August 2005

gp120 is a subunit of the Env (viral envelope protein) of HIV-1. The protein consists of inner and outer domains linked by a bridging sheet. Several gp120 residues that bind the neutralizing antibody 17b as well as the cellular co-receptor CCR5 (CC chemokine receptor 5), are located in the bridging sheet. Peptides that mimic the 17b-binding regions of gp120 would be useful potential immunogens for the generation of neutralizing antibodies against HIV-1. Towards this end, a 26-residue, four-stranded β-sheet peptide was designed on the basis of the structure of the bridging sheet, and its structure was characterized in methanol by NMR. In methanol, amide and α-proton resonances were well resolved and dispersed. A number of interstrand NOEs (nuclear Overhauser effects) were observed, providing good evidence for multiple turn β-hairpin structure. NOEs also provided good evidence for all Xxx–D-Pro bonds in the trans configuration and all three turns formed by a two residue D-Pro–Gly segment to be of type II′ turn. The structure conforms well to the designed four-stranded β-sheet structure. Approx. 20% of the peptide was estimated to adopt a folded conformation in water, as evidenced by CD spectroscopy. This was consistent with smaller, but still significant, downfield shifts of CαH protons relative to random-coil values. A second peptide was designed with two disulphide bonds to further constrain the peptide backbone. While structured in methanol, this peptide, like the previous one, also exhibits only partial structure formation in water, as evidenced by CD spectroscopy.