bluuebunny/crossref_metadata_2025_split huggingface dataset:
Die Kristallstrukturen von Ph3AsCI2 und β-Ph3AsBr2 / Crystal Structures of Ph3AsCI2 and β-Ph3AsBr2
Authors: Neumüller Bernhard , Chitsaz Soheila , Dehnicke Kurt 
Published: February 2015

Colourless single crystals of Ph3AsCl2 as well as of β-Ph3AsBr2 were obtained from acetonitrile solutions and were suitable for X-ray structure determinations. Ph3AsCl2: Space group P212121, Z = 4, lattice dimensions at -90 °C: a = 1247.9(2), b = 1267.5(1), c = 1033.4(1) pm, R x = 0.0484.
β-Ph3AsBr2: Space group P1̄ , Z = 4, lattice dimensions at -80 °C: a = 949.1(1), b = 1189.7(1), c = 1693.7(2) pm, a = 98.32(1)°, ß = 103.64(1)°, γ = 109.44(1)°, R x - 0.0628. The structures consist of Ph3AsX2 molecules (X = Cl, Br) with trigonalbipyramidal coordination of the arsenic atom with the halogen atoms in the axial positions.
Synthesis and Structure of Chiral Silatranes Derived from Terpenes
Authors: Wagner Gabriele , Herrmann Rudolf , Pedersen BjØrn , Scherer Wolfgang 
Published: February 2015

Abstract
Starting with the chiral pool compounds (-)-menthone, (-)-limonene, (-)-β-pinene, and (-)-carvone, new homochiral triethanolamine derivatives were obtained and converted to chi­ral silatranes. These silatranes were characterized by crystal structure analyses and NMR techniques. Conformational analyses in the solid state and in solution show that the chiral terpene residues determine the direction of the ring puckering of the silatrane moiety.
Syntheses and Characterization of 1-Haloazagermatranes
Authors: Shutov Pavel L. , Karlov Sergey S. , Lorberth Jörg , Zaitseva Galina S. 
Published: February 2015

Abstract
Germanium, Azagermatranes The reaction of tris(dimethylamino)halogermanes, (Me2N)3GeHal (7, Hal = Cl; 8 , Hal = Br), with tris(2-aminoethyl)amines, N(CH2CH2NHR)3 (5, R = H; 6 , R = Me), yield l-halo-N,N',N"-azagermatranes (1, X = Cl, R = H; 2, X = Br, R = H; 3, X = Cl, R = Me; 4, X = Br, R = Me). Treatment of 4 with n-butyllithium affords l-n-butyl-N,N',N"-trimethylazagermatrane (14) in high yield. Reactions of n-BuLi with 7 or (Me2N)4Ge (13) lead to the formation of (Me2N)3Ge-n-Bu (15). On treatment of 15 with 5 the 1 -n-butylazagermatrane 16 was obtained. The molecular composition and the structures of all new compounds were established by elemental analyses, 1H and 13C NMR spectroscopy and mass spectrometry.
Synthese und Charakterisierung von cis- und trans-Dicyclohexyl-3,3′,4,4′- tetracarbonsäuren und ihren Dianhydriden / Syntheses and Characterization of cis- and trans-Dicyclohexyl-3,3′,4,4′- tetracarboxylic Acids and their Dianhydrides
Authors: Shiotani Akinori 
Published: February 2015

Abstract
cis- and trans-Dicyclohexyl-3,3′,4,4′-tetracarboxylic acid and their dianhydrides were prepared from tetramethyl dicyclohexyl-3,3′,4,4′-tetra-carboxylates by hydrolysis and subsequent dehydration. The trans dianhydride 2b was found to be sensitive to temperature. However, once the imide ring is formed in the reaction with an amine, the model compound is thermostable. The products were characterized by 1H and 13C NMR, and also by two-dimensional COSY spectroscopy. In the hydrolysis of cis-tetramethyl dicyclohexyl-3,3′,4,4′-tetracarboxylates in steam under high-pressure, trans-dicyclohexyl-3,3′,4,4′-tetracarboxylic acid was formed, while the treatment of cis-dicyclohexyl-3,3′,4,4′-tetracarboxylic acid in steam under high-pressure afforded also trans-dicyclohexyl-3,3′,4,4′-tetracarboxylic acid. In a deuterium tracer experiment of cis-1a, the 3,3′,4,4′-tetradeuterated dicyclohexyl-3,3′,4,4′-tetracarboxylic acid 2a was formed. An isomerization mechanism was postulated from this findings.
A One-Dimensional Polymeric Form of the Polycation Te8
2+ in the Structure of Te8[Bi4Cl14]
Authors: Beck Johannes , Stankowski Alexander 
Published: February 2015

Abstract
The reaction of Te, TeCl4 and BiCl3 in a sealed evacuated glass ampoule in a temperature gradient 160 to 90 °C yields Te8[Bi4Cl14] as black platelike crystals with a golden lustre which are deposited in the temperature zone 150 to 130 °C. The best yield is obtained with a Te/TeCl4/BiCl3 molar ratio of 15/3/4. The crystal structure determination (orthorhombic, P212121, a = 879.9(3), b = 1642.3(4), c = 2267.3(8) pm, Z = 4) shows that Te8[Bi4Cl14] consists of a novel one-dimensional (Te8
2+)„ polycation and a two-dimensional chlorobismutate anion Bi4Cl14
2-. The structure of the cation consists of boat shaped Te6 rings which are connected in the 1,4-positions by Te2 groups to a one-dimensional polymeric strand. The structure is substantially different from the previously reported Te8
2+ polycations in Te8[WCl6]2 and Te8[MCl6] (M = Zr, Hf, Re) where discrete bicyclic clusters with only weak interionic interactions are present. The Bi4Cl14
2- ion can be described as built up of BiCl3 molecules which are connected by Cl- ions to a two-dimensional network [(BiCl3)4(Cl-)2]n.
Kristall- und elektronische Struktur von LaAlSi2 / Crystal and Electronic Structure of LaAlSi2
Authors: Kranenberg Christian , Johrendt Dirk , Mewis Albrecht , Kockelmann Winfried 
Published: February 2015

Abstract
LaAlSi2 (a = 4.196(2), c = 11.437(7) Å; P3̄ml; Z = 2) was synthesized by arc-melting of preheated mixtures of the elements. The compound was investigated by means of X-ray methods and by neutron diffraction. The crystal structure can be described as a stacking variant of two different segments. The first one corresponds to the CaAl2Si2 structure type (LaAl2Si2), the second one with the A1B2 structure type (LaSi2). The segments are stacked along [001]. The electronic structure of the compound is discussed on the basis of LMTO band structure calculations.
Secondary Bonding Interactions in Some Halopyridinium and Dihalopyridinium Halides
Authors: Frey Matthias , Jones Peter G. 
Published: February 2015

Abstract
The packing motifs of 2-and 3-chloropyridinium chloride can be interpreted in terms of classical hydrogen bonds N+-H···Cl- and non-classical C-H···Cl-" interactions, with halo-gen-halogen contacts playing a subordinate role. In the corresponding bromine derivatives, Br···Br interactions are much more important. Of the dihalo derivatives, 3,5-dichloropyridinium chloride crystallises with classical linear hydrogen bonds of the form N+-H···Cl- , but its chlorine-chlorine interactions are at best weak; the corresponding bromine derivative displays aggregates of bromine atoms and three-centre hydrogen bonds N+-H (···Br-)2 .
29Si-29Si and 29Si-13C Indirect Nuclear Spin-Spin Coupling, and Isotope-Induced Chemical Shifts 1Δ 12/13C(29Si) and 1Δ 28/29Si(13C), Determined for Silenes Stabilized by Intramolecular N-Si Coordination
Authors: Wrackmeyer Bernd , Oehme Hartmut 
Published: February 2015

Abstract
Silicon, Silenes Two intramolecularly donor-stabilized silenes, l-(8-dimethylamino-l-naphthyl)-l,2,2-tris-(trimethylsilyl)silene (1), and l-[bis-2 ,6 -(dimethylaminomethyl)phenyl]-l,2 ,2 -tris(trimethyl-silyl)silene 2, were studied by 2 9 Si and C NMR spectroscopy, using polarization transfer techniques in order to determine coupling constants V (2 9 Si,2 9 Si) in = 1,2, 3) and '/ (2 9 Si,l3 C) together with isotope-induced chemical shifts 1 zA12/l3 C(2 9 Si) and Z\2 8 / ~9 Si(C).
Pyrazino-methyl-ethylenedithio- tetrathiafulvalene, Precursor o τ-Phase Conductors
Authors: Papavassiliou G. C. , Terzis A. , Raptopoulou C. P. 
Published: February 2015

Abstract
Modifications of the previously reported meth­ods of preparation of racemic pyrazino-methyl-ethylenedithio-tetrathiafulvalene, i.e., 2-(5,6-dihy-dro-5-methyl-1,3-dithiolo[4,5-b][1,4]dithiin-2-ylidene)-1,3-dithiolo[4,5-b]pyrazine, and their cat­ ion radical salts with linear counter anions are re­ ported. ESR spectra and preliminary X-ray dif­ fraction measurements indicate that the salts crystallize in the τ-phase (tetragonal system).
Synthesis and Crystal Structure of (dmaaH)2(dmaH)2[P12Sn12N12(NH)2] · 4 dmaa, dmaa = N,N-Dimethylacetamide, dma = Dimethylamine, an Anhydrous Example of the P12N14Cage
Authors: Roth Stephan , Schnick Wolfgang 
Published: February 2015

Abstract
The title compound (dmaaH)2(dmaH)2[P12S12N12(NH)2] · 4 dmaa (1) was obtained by crys­tallization from a saturated solution of anhydrous P12S12N8(NH)6 in N,N-dimethylacetamide (dmaa) as large single crystals. According to the X-ray structure determination (P21/n, a = 1421.8(1), b = 1556.5(2), c = 1645.8(1) pm, ß = 112.207(6)°, Z = 2, 6388 observed reflections, R1 = 0.046, wR2 = 0.111) the anionic cage is built up from twelve P3N3 rings in boat confor­ mation. N,N-dimethylammonium ions (dmaH+) are directly connected to the cage, and pairs of N,N-dimethylacetamidonium ions (dmaaH+) and N,N-dimethylacetamide molecules (dmaa) are interconnected by hydrogen-bonds.
Interpenetrierende Clusterstränge in der Kristallstruktur von K0,77Nb6Cl15 / Interpenetrating Cluster Chains in the Structure of K0.77Nb6Cl15
Authors: Nägele Andreas , Day Cynthia , Lachgar Abdessadek , Meyer H.-Jürgen 
Published: February 2015

The solid state reaction of KCl, NbCl5 and Nb powder at 760 °C yielded black crystals of KNb6Cl15. The structure of the compound has been determined using single-crystal X-ray methods. KNb6Cl15 crystallizes in the orthorhombic space group Pmma (no. 51) with lattice constants a = 1780.1(2), b = 1341.4(1), and c = 925.5(1) pm, Z = 4, and R1 = 0.039 for all 2727 observed reflections.
[(Nb6Cl12
i)Cl6/2
a-a]- anions in the structure are linked via two Cla-a bridges to form one set of linear and one set of kinked chains along the crystallographic c and a directions. Four remaining Cla-a bridges interconnect both sets of chains to a three-dimensional network. The potassium occupancy on a 4k site was refined to a value of 0.384(3) consistent with the formula K0.77Nb6Cl15-.
Ternäre Niobchloride des Formeltyps ANb6Cl15 wurden bereits verschiedentlich beschrieben. Verbindungen mit A = Li [1] und Na [2] kristallisieren kubisch (Ia3̅d) mit identischen Schweratomstrukturen. Die Alkalimetall-Ionen Li (KZ = 4) und Na (KZ = 6 ) besetzen in den Strukturen ANb6Cl15 aber unterschiedliche Splitlagen und sind dynamisch fehlgeordnet. Die Vertreter mit A = In und TI [3] kristallisieren orthorhombisch (Pmma). Ihre Kationen befinden sich in zweifach überdachten, würfelförmigen Cl-Umgebungen (KZ = 10). Die Kenntnis des Formeltyps ANb6Cl15 mit schweren Alkalimetallen ist noch unvollständig. Einkristallstrukturuntersuchungen für A = Rb, Cs ergaben Kationenfehlordnungen [4, 5].
Für die Verbindung KNb6Cl15 wurde eine Einkristallstrukturbestimmung durchgeführt (Tab. 1). Die Verbindung kristallisiert orthorhombisch in der Raumgruppe Pmma (Nr. 51) mit den Gitterkonstanten a = 1780,1(2), b = 1341,4(1) und c = 925,5(1) pm mit Z = 4 und ist isotyp zu den Inund TI-Verbindungen. Die Besetzung der K-Position (4k-Lage, mx-Punktsymmetrie) wurde zu 0,384(3) verfeinert, was der Zusammensetzung K0.77Nb6Cl15 entspricht (Tab. 2)#. Die Nb-Nb-Abstände in KNb6Cl15 liegen zwischen 291,47(6) und 296,45(7) pm, die Bindungslängen Nb-ClI betragen 243,3(1) - 247,18(9) und die Nb-Cla-Abstände 258,7(2) - 271,40(9) pm.
Ternary Rare Earth and Uranium Nickel Arsenides Ln2NiAs2 (Ln = Tb -Yb), LnNiAs (Ln = La -Nd, Sm, Gd, Dy -Yb), and UNiAs
Authors: Jeitschko Wolfgang , Terbüchte Ludger J. , Rodewald Ute Ch. 
Published: February 2015

Abstract
The new compounds Tm2NiAs2 and Yb2NiAs2 crystallize with a hexagonal structure similar to that reported for Zr2NiAs2. It was refined for Tm2NiAs2 from single-crystal X-ray data in the polar space group P63mc\ a = 408.4(1), c = 1374.2(3) pm, R = 0.044 for 176 structure factors and 16 variable parameters. The compounds Ln2NiAs2 (Ln = Tb -Er) are confirmed to crystallize with an analogous structure from X-ray powder data. In contrast to the earlier structure refinement of Zr2NiAs2 in the higher-symmetric space group P 63/mmc, where the honeycomb layers of nickel and arsenic atoms are described as planar, these layers are puckered in Tm2NiAs2. These compounds are expected to undergo a displacive phase transition, with the centrosymmetric space group P63/mmc to be correct at high temperature. Since the room temperature structure is polar, these compounds might be classified as ferroelectric from a symmetry point of view. The equiatomic title compounds LnNiAs and UNiAs crystallize with a related hexagonal structure corresponding to a superstructure of the AIB2 type with lattice constants varying between a = 416.2(1), c = 1636.1(4) pm for LaNiAs and a = 401.9(2), c = 1488.5(5) pm for YbNiAs. The crystal chemistry of these hexagonal structures is briefly discussed. Using oxidation numbers chemical bonding in the lanthanoid containing compounds may be rationalized with the formulas (Ln+3)2Ni(As-3)2 and Ln+3NiAs-3, thus suggesting semiconducting behavior.
Na2ZrSe3, ein neues Chalcogenometallat(IV) mit Schichtstruktur/Na2ZrSe3, a New Chalcogenometallate(IV) with a Layered Structure
Authors: Harringer Norbert A. , Kolb Andreas , Klepp Kurt O. 
Published: February 2015

Abstract
Orange red crystals of Na2ZrSe3 were obtained by the reaction of Na2Se, Zr and Se at 800 °C. The new compound is monoclinic, s. g. C2/m with a = 6.952(2), b = 12.01(1), c = 7.257(2) Å, ß = 108.81(2)°, Z = 4. Its crystal structure was determined from single crystal diffractometer data (Mo-Kα-radiation) and refined to a conventional R of 0.016. It is characterized by layers based on a distorted ccp packing of Se-atoms where all metal atoms occupy octahedral voids in an ordered fashion. Zr atoms are located on the nodes of a 63-net forming CrCl3 type selenozirconate layer (d(Zr-Se) = 2.702 Å).
DFT Calculations of the Structures and IR Frequencies of the Anionic Fulminate Complexes [Co(CNO)6]3-, [Ni(CNO)4]2-, [Zn(CNO)4]2-, [Pt(CNO)4]2-, [Au(CNO)2]- and [Hg(CNO)4]2-
Authors: Beck Wolfgang , Klapötke Thomas M. 
Published: February 2015

Abstract
The structural parameters and IR frequencies of the following anionic fulminate complexes were computed at the density functional BPW91 level of theory using a 6-31++G(2d) basis for C, N, O, Co, Ni, and Zn and quasi-relativistic ECP60MWB core potentials for Pt, Au and Hg:
[Co(CNO)6]3- (Oh), [Ni(CNO)4]2-(D4h),
[Zn(CNO)4]2- (Td), [Pt(CNO4]2-(D4h),
[Au(CNO)2]- (Dxh) and [Hg(CNO)4]2-(Td). The structures were optimised within the symmetries stated above and were found to represent true minima (number of imaginary frequencies, NIMAG = 0). The agreement between the calcu­ lated structural parameters and characteristic asymmetric and symmetric CNO stretching fre­ quencies is very good for all complexes.
Periodic Solutions for Damped Vibration Problems
Authors: Ziheng Zhang  , Hongjun Li  
Published: February 2015

In this paper we are concerned with the following damped vibration problemÂ where , Â with Â and , Â is -periodic in Â such that Â is a -periodic, positive definite symmetric matrix and Â satisfies the global Ambrosetti-Rabinowitz condition or is subquadratic at infinity. By use of the Mountain Pass Theorem or the genus properties in the critical theory, we establish some new criteria to guarantee the existence and multiplicity of periodic solutions. Recent results in the literature are generalized and significantly improved.
Prevalence of Duchenne and Becker Muscular Dystrophies in the United States
Authors: Romitti Paul A. , Zhu Yong , Puzhankara Soman , James Katherine A. , Nabukera Sarah K. , Zamba Gideon K.D. , Ciafaloni Emma , Cunniff Christopher , Druschel Charlotte M. , Mathews Katherine D. , Matthews Dennis J. , Meaney F. John , Andrews Jennifer G. , Conway Kristin M. Caspers , Fox Deborah J. , Street Natalie , Adams Melissa M. , Bolen Julie 
Published: February 2015

OBJECTIVE:To estimate prevalence of childhood-onset Duchenne and Becker muscular dystrophies (DBMD) in 6 sites in the United States by race/ethnicity and phenotype (Duchenne muscular dystrophy [DMD] or Becker muscular dystrophy [BMD]).METHODS:In 2002, the Centers for Disease Control and Prevention established the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet) to conduct longitudinal, population-based surveillance and research of DBMD in the United States. Six sites conducted active, multiple-source case finding and record abstraction to identify MD STARnet cases born January 1982 to December 2011. We used cross-sectional analyses to estimate prevalence of DBMD per 10 000 boys, ages 5 to 9 years, for 4 quinquennia (1991–1995, 1996–2000, 2001–2005, and 2006–2010) and prevalence per 10 000 male individuals, ages 5 to 24 years, in 2010. Prevalence was also estimated by race/ethnicity and phenotype.RESULTS:Overall, 649 cases resided in an MD STARnet site during ≥1 quinquennia. Prevalence estimates per 10 000 boys, ages 5 to 9 years, were 1.93, 2.05, 2.04, and 1.51, respectively, for 1991–1995, 1996–2000, 2001–2005, and 2006–2010. Prevalence tended to be higher for Hispanic individuals than non-Hispanic white or black individuals, and higher for DMD than BMD. In 2010, prevalence of DBMD was 1.38 per 10 000 male individuals, ages 5 to 24 years.CONCLUSIONS:We present population-based prevalence estimates for DBMD in 6 US sites. Prevalence differed by race/ethnicity, suggesting potential cultural and socioeconomic influences in the diagnosis of DBMD. Prevalence also was higher for DMD than BMD. Continued longitudinal surveillance will permit us to examine racial/ethnic and socioeconomic differences in treatment and outcomes for MD STARnet cases.
Chemical and Crystal Characterization of the Oxide Film Formed in 304L SS Under Autoclave Conditions, With and Without Crevice Formation
Authors: Sánchez Ángeles Díaz , Ramírez Aida Contreras , Juárez Carlos Arganis 
Published: February 2015

ABSTRACTThe principles of Stress Corrosion Cracking (SCC) are supported in the behavior of the oxide film formed into a crack; in fact the active dissolution of metal atoms after a film rupture and until fill repassivation is the base of slip dissolution model which is a good model to justified the crack tip advance in stainless steels (SS) used in vessel internal components for the nuclear industry. This paper shows the analyzed made at the oxide film formed on samples of 304L SS sensitized and non sensitized, under autoclave conditions (288°C, 8MPa) with and without crevice geometric formation, using SEM, XRD and Raman Spectra.The crevice and no crevice condition allow establish the difference of an oxide formed on a free surface (no crevice) and the oxide formed on the wall in a crack (crevice); the chemical and physical properties of oxide film can alter the mechanism and kinetics of SCC process, so the difference between these two conditions will give more information about the behavior of the oxide film.
Spark Plasma Sintering of Yttria-Stabilized Zirconia/Titanium Nitride Composites
Authors: Silva Paulo S. M. , Fonseca Fabio C. 
Published: February 2015

ABSTRACTComposites of 8 mol% yttria-stabilized zirconia (YSZ) and titanium nitride (TiN) were obtained by mechanical mixing of commercial powders. High-density samples of (1-x) YSZ / x TiN, with x = 0, 25, 50, and 75 wt.%, were obtained by spark plasma sintering (SPS) at 1450 °C for 5 min. Surface contamination with carbon from the SPS was eliminated by diamond sawing of parallel surfaces. X-rays diffraction analyses showed that samples are composed by a mixture of the initial phases, without appreciable reaction as inferred from calculated lattice parameters. dc 4-probe electrical measurements in the 100-850°C under showed that samples have a metallic behavior, indicating that the percolation threshold was attained for the sample with the lowest content of the TiN (x=25 wt.%), which corresponds to ∼27 vol.%.
Undergraduate Material Research in a Land Grant HBCU to Sustain Local Farmers Communities
Authors: Volkis Victoria V. , Sauder Deborah G. 
Published: February 2015

ABSTRACTLand-Grant Universities including those that were developed under the second Morrill Act in 1890 have historically been a key resource for the best scientifically based information for agricultural production. The University of Maryland Eastern Shore (UMES) is situated on the Eastern Shore of Maryland, a critical area, with small farms and underserved farmers. This unique location serves as an interface between University specialty crop research and those farmers. While prices of crops such as corn and soy, which traditionally have been a major source of income for local farmers, have increased dramatically over the past years, small farms cannot generate enough income from these commodity crops alone, and a need alternatives for extra income. At UMES agricultural, chemical and material research specialists formed a special research and training cluster in which they work jointly on non-traditional and non-food related applications of specialty crops in the field of material research leading to non-traditional applications of such crops. Examples of such research are: (i) blending natural specialty crops extracts with polymers to develop natural and effective anti-foaling coating to prevent biofilm formation on objects including military ships, platforms etc.; (ii) using biocompatible polymeric chitosan-based blends as sorbents for reversible carbon dioxide capturing and controlled release in algae-growing reactors and in the process of transforming biomass into alcohol by fermentation to increase the effectiveness of biomass use. Only about 20% of students-researchers in the cluster are graduate students and the rest are undergraduates. The main focus is to provide undergraduate students with research experience as a powerful tool for their education and career development. Focus on students performing outstanding research through their undergraduate education is the main priority in UMES. Working on the material research projects described above, our material cluster has developed some educational practices for effectively involving undergraduate students into research. These practices include early involvement, the development of special workshops and training settings for fast project starts, working in small groups lead by more experienced students, picking projects that can be easily divided into small tasks suitable to undergraduate student’s schedules, and participation in scientific conferences for undergraduates and others. In this presentation we will review two material research projects for undergraduate students mentioned above and will show how our best practices are implemented in each of these projects.
A Case Study Examination of Structure and Function in a State Health Department Chronic Disease Unit
Authors: Alongi Jeanne 
Published: February 2015

Objectives. I explored the structural and operational practices of the chronic disease prevention and control unit of a state health department and proposed a conceptual model of structure, function, and effectiveness for future study. Methods. My exploratory case study examined 7 elements of organizational structure and practice. My interviews with staff and external stakeholders of a single chronic disease unit yielded quantitative and qualitative data that I coded by perspective, process, relationship, and activity. I analyzed these for patterns and emerging themes. Results. Chi-square analysis revealed significant correlations among collaboration with goal ambiguity, political support, and responsiveness, and evidence-based decisions with goal ambiguity and responsiveness. Conclusions. Although my study design did not permit conclusions about causality, my findings suggested that some elements of the model might facilitate effectiveness for chronic disease units and should be studied further. My findings might have important implications for identifying levers around which capacity can be built that may strengthen effectiveness.