bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theory of electron confinement and electron effective mass in dilute nitride alloys and heterostructures
Authors: O'Reilly E. P. , Lindsay A. , Tomić S. , Klar P. J. 
Published: October 2004

AbstractThe band‐anti‐crossing (BAC) model describes the strong band‐gap bowing at low N composition x in Ga(In)NxAs1–x in terms of an interaction between the conduction band edge and a higher‐lying band of localized nitrogen resonant states. We first present an analytical technique based on the BAC model to calculate electron energies in Ga(In)NAs square quantum well (QW) structures. We then show through detailed comparison with photoreflectance measurements that the BAC model successfully describes ground and excited state interband transition energies in bulk and QW GaNAs samples, both at ambient pressure and as a function of hydrostatic pressure. Turning to the conduction band dispersion, we find that the two‐level BAC model is insufficient, and must be modified to give a quantitative understanding of the unexpectedly large electron effective mass values observed in some GaNAs samples, which we attribute to hybridisation between the conduction band edge and nitrogen states close to the band edge. We predict a non‐monotonic variation of electron mass with hydrostatic pressure in many GaNAs samples. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Aortopulmonary window with ventricular septal defect and pulmonary atresia: prenatal diagnosis and successful early surgical correction
Authors: Kuehn A. , Oberhoffer R. , Vogt M. , Lange R. , Hess J. 
Published: October 2004

AbstractWe report a case in which aortopulmonary window (APW) in combination with pulmonary atresia was diagnosed correctly in a neonate by echocardiography. Prenatal echocardiography showed progression of tetralogy of Fallot to pulmonary atresia with retrograde pulmonary perfusion, concealing the concomitant APW in fetal life. Due to intractable heart failure, primary correction was successfully performed at the age of 4 weeks (weight 2280 g). Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Sr10[Mo2N6][MoN4]2 and β‐Sr3MoN4
Authors: Bailey Mark S. , McGuire Michael A. , DiSalvo Francis J. 
Published: October 2004

AbstractTwo new phases in the strontium‐molybdenum‐nitrogen phase diagram have been synthesized. Single crystals of Sr10[Mo2N6][MoN4]2 were grown from a mixed sodium‐gallium melt at 900 °C in a sealed niobium tube. It crystallizes in the triclinic space group $P{\bar 1}$ (Z = 1) with a = 6.421(1), b = 9.190(2), c = 9.263(2) Å and α = 64.939(5), β = 82.961(6) and γ = 89.692(6)°. The new, orthorhombic polymorph of Sr3MoN4 was synthesized as a polycrystalline powder from an intimate mixture of Sr2N and molybdenum metal in the presence of N2. Rietveld analysis shows it to crystallize in Pbca (Z = 8) with a = 10.4835(2), b = 9.7374(2) and c = 11.5114(2) Å. Studies suggest that excess nitrogen is essential to the formation of this polymorph. Sr10[Mo2N6][MoN4]2 is the first molybdenum nitride to contain the anionic unit [Mo2N6]8‐, which appears as isolated, edge‐sharing pairs of MoN4 that facilitate MoV‐MoV bonding. This compound also contains isolated [MoN4]6‐ tetrahedra and the presence of these two units results in the first mixed valent molybdenum nitride. Resistivity measurements show it to be insulating.
Einkristalluntersuchungen an Cs[AuF4], Cs[Au2F7] und U2F7[AuF4]
Authors: Schmidt R. , Müller B. G. 
Published: October 2004

AbstractAnhand von Einkristalldaten konnte mit blaßgelbem Cs[AuF4] das letzte Alkalimetallfluoroaurat M[AuF4] (M = Li‐Cs) strukturell charakterisiert werden. Es kristallisiert orthorhombisch in einem neuen Strukturtyp, Immm (Nr.71) mit a = 548, 6, b = 658, 9 und c = 1265, 5 pm, Z = 4.Als Nebenprodukt wurde gelb‐braunes Cs[Au2F7] erhalten. Die Verbindung kristallisiert monoklin, C2/c (Nr.15) mit a = 1136, 5, b = 1082, 0 und c = 737, 4 pm, β = 123, 4, Z = 4. Charakteristisches Strukturmerkmal ist die bei Fluoroauraten bislang erstmals beobachtete [Au2F7]‐‐Baugruppe.Schließlich gelang noch die gezielte Synthese von blaßgelbem U2F7[AuF4]. Die Atomanordnung entspricht der in Th2F7[AuF4] (I4/mmm, a = 1132, 37, c = 632, 99 pm, Z = 4).
Kopplung metallorganischer Reaktionszentren durch den nichtplanaren Brückenliganden 2, 3‐Bis(2‐pyridyl)pyrazin
Authors: Berger Sascha , Scheiring Thomas , Fiedler Jan , Kaim Wolfgang 
Published: October 2004

AbstractDer vielverwendete Ligand 2, 3‐bppz = 2, 3‐Bis(2‐pyridyl)pyrazin und seine Komplexe [(2, 3‐bppz){(C5Me5)ClM}n](PF6)n, M = Rh oder Ir und n = 1 oder 2, wurden durch cyclische Voltammetrie und UV/VIS‐Spektroelektrochemie untersucht. Sowohl für die einkernigen als auch — ungewöhnlicherweise — für die zweikernigen Komplexe werden nur Chlorid‐dissoziative Zweielektronenreduktionsprozesse beobachtet. Einer der Vorläuferkomplexe, [(2, 3‐bppz)(C5Me5)ClIr]Cl·2H2O, konnte strukturell charakterisiert werden, er weist eine deutlich nichtplanare Konformation des 2, 3‐bppz‐Liganden auf.
K10M4M′4S17 (M = Mn, Fe, Co, Zn; M′ = Sn, Ge) and Cs10Cd4Sn4S17: Compounds with a Discrete Supertetrahedral Cluster
Authors: Palchik Oleg , Iyer Ratnasabapathy G. , Canlas Christian G. , Weliky David P. , Kanatzidis Mercouri G. 
Published: October 2004

AbstractThe cluster compounds K10Zn4Sn4S17, K10Mn4Sn4S17, K10Fe4Sn4S17, K10Co4Sn4S17, Cs10Cd4Sn4S17 and K10Zn4Ge4S17 are described. The structures of these compounds, refined by single‐crystal X‐ray diffraction techniques, contain the discrete cluster [M4M′4S17]10‐ (M = Zn, Mn, Co, Fe, Cd; M′ = Sn or Ge) which has the structure of Si8C17H36. It is built from the sulfur‐connected tetrahedral SnS4 and MS4 units with the additional quadruply bridging sulfur atom at the center of the cluster. All compound show some solubility and stability in water and formamide. Cs10Cd4Sn4S17 and K10Zn4Ge4S17 show photoluminescence at room temperature.The magnetic properties of K10Mn4Sn4S17, K10Fe4Sn4S17, K10Co4Sn4S17 indicate strong antiferromagnetic interactions arising from spin coupling within the cluster but their magnetic susceptibility is characterized with a discrepancy between field‐cooled and zero field‐cooled measurements.
Anion Distribution in Zr2ON2
Authors: Bredow Thomas , Lerch Martin 
Published: October 2004

AbstractThe effect of the distribution of N and O ions on the lattice energy of Zr2ON2 has been investigated with periodic first‐principles calculations. It was found that the ordered Ibca structure is energetically unstable with respect to interchanges of N and O atoms. The stabilization has been correlated with the N‐N and O‐O coordination. The average coordination numbers of the most stable configuration are similar to those of a statistical anion distribution. The calculated electronic structure is in agreement with experimental observations.
Two Novel Thioantimonates(III) with the Same Stoichiometric Sb:S Ratio but Different Crystal Structures: Solvothermal Synthesis, Crystal Structures, Thermal Stability and Spectroscopy of (C6N3H17)Sb6S10 and (C7N2H13)3Sb9S15
Authors: Spetzler Volker , Kiebach Ragnar , Näther Christian , Bensch Wolfgang 
Published: October 2004

AbstractThe two novel thioantimonates(III) (C6N3H172+)Sb6S10 (I) and (C7N2H13+)3Sb9S15 (II) were synthesized under solvothermal conditions reacting Sb and S with the amines 1‐(2‐aminoethyl)‐piperazine (C6N3H15) and 1, 5‐diazabicyclo[4.3.0.]non‐5‐en (DBN, C7N2H12), respectively. The compounds crystallize as red needles in the monoclinic non‐centrosymmetric space group P21 (I) and in the monoclinic space group P21/c (II) with lattice parameters a = 6.120(4) Å, b = 17.759(1) Å, c = 11.478(7) Å, β = 90.70(7)° for I and a = 10.2643(6) Å, b = 23.648(2) Å, c = 20.4655(11) Å, β = 104.430(7)° for II.In both compounds the primary building units (PBUs) are trigonal SbS3 pyramids and SbS4 moieties. The interconnection of these PBUs leads to the formation of six‐membered rings Sb3S3 and Sb3S4 semi‐cubes in I which are joined via common S atoms to form the one‐dimensional [Sb6S10]2‐ anion being directed along [001]. Neighbored chains are arranged in a way that pockets are formed which host the organic cations. The ammonium groups of the organic molecules are oriented towards the anion ensuring optimal S···H bonding interactions. Taking into account the longer Sb‐S bonds above 3Å a three‐dimensional network is formed with large cages containing the organic cations. In compound II the SbS3 pyramids and the SbS4 units each form individual chains by vertex linking. The central chain is exclusively formed by SbS4 units whereas the other two chains are composed of SbS3 pyramids. The interconnection of the chains via common corners yields the one‐dimensional [Sb9S15]3‐ multiple chain anion. Due to the connection mode Sb4S4 rings are formed which are condensed along [001]. The chains are stacked along [100] with an inter‐chain separation of about 7Å. In the [010] direction the anions are lined‐up with the shortest distance between neighbored anions of about 3.4Å. With the long Sb‐S distances layers within the (100) plane are formed. At elevated temperatures both compounds decompose via an internal redox reaction into Sb2S3 (Stibnite) and Sb. The optical band gaps of about 2 eV indicate that both compounds are semiconductors.
High‐Pressure Synthesis and Crystal Structure of the Structurally New Orthorhombic Rare‐Earth Meta‐Oxoborates γ‐RE(BO2)3 (RE = La ‐ Nd)
Authors: Emme Holger , Despotopoulou Christina , Huppertz Hubert 
Published: October 2004

AbstractThe new meta‐oxoborates γ‐RE(BO2)3 (RE = La ‐ Nd) (≡ REB3O6) were obtained as colourless (La, Ce), light green (Pr) and pale violet (Nd) crystalline powders by the reaction of CeO2, Pr6O11, or RE2O3 (RE = La, Nd) and B2O3 in a Walker‐type multianvil apparatus under high‐pressure/high‐temperature conditions of 7.5 GPa and 1000 °C. The single crystal X‐ray structure determination of γ‐Ce(BO2)3 revealed: Pca21, a = 1845.7(2), b = 446.8(2), c = 429.5(2) pm, Z = 4, R1 = 0.0265, wR2 = 0.0451 (all data). For the isotypic compounds γ‐RE(BO2)3 (RE = La, Pr, Nd) the corresponding lattice parameters were obtained from powder data. Structurally, the compounds represent a new type of rare‐earth meta‐oxoborate RE(BO2)3 in addition to the well characterized monoclinic (RE = La ‐ Nd, Sm ‐ Lu; C2/c) and orthorhombic (RE = Tb ‐ Lu; Pnma) phases. Considering the increasing number of polymorphs, we introduced greek letter prefixes to the rare‐earth meta‐oxoborates, labeling the former known monoclinic phases as α‐RE(BO2)3 (space group: C2/c), the orthorhombic phases as β‐RE(BO2)3 (space group: Pnma), and the here presented orthorhombic phases as γ‐RE(BO2)3. Furthermore, we report about temperature‐resolved in‐situ powder‐diffraction measurements, and IR‐spectroscopic investigations into γ‐Ce(BO2)3.
From Gallium Hydride Halides to Molecular Gallium Sulfides
Authors: Schmidbaur Hubert , Nogai Stefan D. 
Published: October 2004

AbstractComplexes of the type (L)GaHCl2, with L = tertiary phosphines or pyridines, have been prepared from (HGaCl2)2 and the ligands in diethyl ether. The products are stable crystalline solids soluble in common organic solvents. The presence of the Ga‐H function has been confirmed by IR and NMR spectroscopy and by single crystal X‐ray diffraction, carried out for the 1:1 adducts with L = PCy3 and PPh3 (two polymorphs) and for the 2:1 adduct with L = (CH2PPh2)2 (dppe, two different solvates). The reaction of PVi3 with (HGaCl2)2 gives an insoluble polymer owing to the hydrogallation of vinyl groups by the gallium hydride units (no Ga‐H functions are left in the product).Treatment of the complexes (R3P)GaHCl2 with H2S, metal sulfides or (Me3Si)2S gave only insoluble, ill‐defined products.‐ The 1:1 adduct (L′)GaHCl2, with L′ = 4‐dimethylamino‐pyridine, reacts with (Me3Si)2S in acetonitrile at ambient temperature to give an only partially sulfur‐substituted product of the net formula (L′)GaSH0.66Cl0.34. With excess ligand L′, under reflux conditions and after longer reaction times, a pyridine complex of the tetranuclear, molecular gallium sulfide Ga4S6 is obtained in low yield. The core of the compound with the composition (L′)4Ga4S6 has an adamantane structure resembling a cluster unit of the binary gallium sulfide polymorphs Ga2S3. The edge‐sharing Ga3S3 six‐membered rings are all in a chair conformation as found previously for the pyridine complexes of the ternary compounds [(L)GaEX]3(with E = S, Se and X = Cl, Br) and for the bicyclic dication [(L)6Ga4S5]2+. Thermolysis and degradation under mass spectrometry conditions lead to sublimation of L′ and leave amorphous Ga2S3. The reaction of (L′)GaCl3 with (Me3Si)2S did not afford any molecular gallium sulfide complex. A comparison of the structural data for (L′)GaCl3 and (L′)4Ga4S6 suggests a much poorer acceptor character of the gallium sulfide cluster.
Chemischer Transport ternärer Cobaltmolybdate — Experimente und Modellrechnungen
Authors: Steiner Udo , Daminova Sofia , Reichelt Werner 
Published: October 2004

AbstractDer Chemische Transport der Phasen im System Co/Mo/O mit den Transportmitteln Cl2 und Br2 wurde im Temperaturgefälle 1173 nach 1073 K untersucht, wobei Einkristalle von Co2Mo3O8, CoO, Co3O4 und Co dargestellt werden konnten, während die abgeschiedenen CoMoO4‐Einkristalle aufgrund einer Phasenumwandlung bei etwa 660 K beim Abkühlen auf Raumtemperatur zerfallen. Ausgangsmaterial waren sowohl phasenreine Proben der ternären Verbindungen als auch Gemenge dreier koexistierender Phasen aus den unterschiedlichen Koexistenzgebieten des Systems. Das beobachtete Transportverhalten wird verglichen mit den Resultaten von Modellrechnungen zum Chemischen Transport und in Abhängigkeit von Ausgangsbodenkörperzusammensetzung, Transportmittelmenge und Feuchtigkeitsgehalt der Ampulle ausführlich diskutiert.
Kupferkomplexe von invers polarisierten Phosphaalkenen RP=C(NMe2)2 (R = t‐Bu, Ph). Molekülstruktur von [Cu3Cl3{μ‐P(t‐Bu)C(NMe2)2}3]
Authors: Weber Lothar , Krümberg Jens , Stammler Hans‐Georg , Neumann Beate 
Published: October 2004

AbstractDie Reaktion äquimolarer Mengen des invers polarisierten Phosphaalkens t‐BuP=C(NMe2)2 (1) und Kupfer(I)chlorid liefert den Komplex [Cu3Cl3{μ‐P(t‐Bu)C(NMe2)2}3] (2) als formales Ergebnis der Cyclotrimerisierung eines 1:1‐Addukts. Analog wird der Komplex [Cu3Cl3{μ‐P(Ph)C(NMe2)2}3] (4) aus dem Phosphaalken PhP=C(NMe2)2 (3) und [Cu{P(OMe)3}3Cl] gewonnen. Die Verbindungen 2 und 4 wurden auf elementaranalytischem und spektroskopischem Weg (1H, 13C{1H}, 31P{1H}‐NMR) charakterisiert. Die Molekülstruktur von 2 wurde durch eine Röntgenstruktur ermittelt.
Schiff Base Formation upon Complexation of Tris(acetylacetonato)iron with N[(CH2CH2NH2)(CH2CH2OH)(CH2CH2CH2OH)]
Authors: Hahn F. Ekkehardt , Jocher Christoph , Lügger Thomas , Pape Tania 
Published: October 2004

AbstractThe reaction of the unsymmetrical aliphatic tripodal ligand N[(CH2CH2NH2)(CH2CH2OH)(CH2CH2CH2OH)] (H4‐3) with tris(acetylacetonato)iron(III) gives the dinuclear bis(μ‐alkoxo) bridged complex [Fe{N(CH2CH2N=C(CH3)CHC(CH3)O)‐ (CH2CH2CH2O)(CH2CH2O)}]2 [Fe(η5, μ‐4)]2 (5). The new ligand 43‐ is obtained by reaction of the primary amine function of H4‐3 with one of the acetylacetonato ligands under imine formation. The iron atoms in complex 5 are coordinated in an octahedral fashion within an N2O4 environment. Complex 5 contains three different alkoxo donor groups.
Fluoromanganat(III)‐Anionen mit neuer tetramerer und Kettenstruktur in (pipzH2)3[Mn4F18(H2O)]·(H2O) und (pipzH2)4[Mn2F9]2[MnF4(H2O)2][MnF4(HF)2]
Authors: Stief Ronald , Massa Werner 
Published: October 2004

AbstractBei systematischen Fällungsversuchen aus flußsauren Lösungen von MnIII und Piperazin konnten u.a. die beiden Titelverbindungen in reiner Form erhalten und ihre Kristallstrukturen röntgenographisch bestimmt werden. (pipzH2)3[Mn4F18(H2O)]·(H2O) kristallisiert orthorhombisch in Raumgruppe Pnma, Z = 4, a = 2050.8(2), b = 1253.0(1), c = 1096.0(1) pm, R = 0.0290. Die Struktur enthält ein neues tetrameres Anion [Mn4F18(H2O)]6‐ aus zwei über eine gemeinsame Ecke verbundenen kantenverknüpften Doppeloktaedern. (pipzH2)4[Mn2F9]2[MnF4(H2O)2][MnF4(HF)2] ist triklin, Raumgruppe $P{\bar 1}$, Z = 1, a = 901.6(1), b = 913.1(1), c = 1308.9(1) pm, α = 70.024(6)°, β = 75.229(6)°, γ = 78.887(6)°. Hier sind analoge Doppeloktaeder mit reiner Fluorkoordination zu Ketten verknüpft. Diese sind durch starke H‐Brücken F···H···F, O···H···F und N···H···F über isolierte oktaedrische Baugruppen [MnF4(H2O)2]‐ und [MnF4(HF)2]‐ sowie die (pipzH2)2+‐Kationen zu einem 3D Netz verbunden. Typisch in beiden Strukturen ist eine starke Oktaederstreckung durch den Jahn‐Teller‐Effekt, wobei die gestreckten Achsen parallel in der Ebene der Doppelverbrückung liegen, so daß beide Mn—F—‐Mn—Brücken stark asymmetrisch sind. Die Ordnung zwischen den Dimeren ist jedoch im Tetramer ferrodistortiv, im Kettenanion antiferrodistortiv.
The Cube‐Shaped Main Group Element Clusters (Bi4S4)4+ and (Bi4Se4)4+ ‐ Synthesis from Chloroaluminate Melts, Crystal Structures and Vibrational Spectra
Authors: Beck Johannes , Schlüter Stefan , Zotov Nicolay 
Published: October 2004

AbstractThe reaction of bismuth and bismuth trichloride with sulfur or selenium, respectively, in a AlCl3/NaCl melt at 130 °C leads to (Bi4S4)[AlCl4]4 1 and (Bi4Se4)[AlCl4]4 2 in the form of red and amber colored crystals. Both crystallize isotypically in the tetragonal space group $I{\bar 4}$ with the lattice constants a = 1181.60(2), c = 1104.75(2) pm for 1 and a = 1199.32(2), c = 1118.64(3) pm for 2. Besides the nearly regular tetrahedral [AlCl4]‐ ions the structures contain (Bi4S4)4+ and (Bi4Se4)4+ cations. These ions are actually of crystallographic S4 symmetry but deviate only slightly from the ideal cubic symmetry. Bi and chalcogen atoms occupy alternatingly the corners of the cubes. 1 and 2 are isotypical to the already known (Bi4Te4)[AlCl4]4, so the series of the cube‐shaped (Bi4E4)4+ ions (E = S, Se, Te) is now complete. Infrared und Raman spectra of 1 und 2 show the vibration modes of both kinds of ions in the region 50 ‐ 600 cm‐1. Symmetry analysis and normal mode calculations of the vibrational spectra confirm the local symmetry of the (Bi4E4) clusters and the [AlCl4] groups.
Carbomolybdate(III): Zur Kenntnis von Pr2[Mo2C3] sowie Strukturbeziehungen zu Er2Mo2C3
Authors: Dashjav Enkhtsetseg , Kreiner Guido , Schnelle Walter , Wagner Frank R. , Kniep Rüdiger 
Published: October 2004

AbstractPr2[Mo2C3] wurde durch Reaktion der Elemente im Lichtbogenofen und anschließenden Wärmebehandlung in gasdicht verschweißten Mo‐Ampullen bei 1500 °C hergestellt. Die Charakterisierung der Verbindung erfolgte über chemische Analysen, Röntgenbeugungsexperimente und metallographische Verfahren. Pr2[Mo2C3] kristallisiert (monoklin, P21/c, Z = 4, a = 597.99(10) pm, b = 665.15(11) pm, c = 1185.60(19) pm und β = 111.631(5)°) in einem neuen Strukturtyp. Die Kristallstruktur enthält ein dreidimensional verknüpftes Polyanion [(Mo2C3)6‐], in dem Molybdän(III) verzerrt tetraedrisch von Carbo‐Liganden umgeben ist. Tetramere Einheiten Mo4C10 aus kantenverknüpften MoC4‐Tetraedern bilden parallel (100) verlaufende Schichtverbände, die entlang [100] über gemeinsame Carbo‐Liganden (Spitzenverknüpfung der MoC4‐Tetraeder) miteinander verbunden sind. Die Umgebungen der Seltenerd‐Kationen entsprechen stark verzerrten (PrC5)‐Koordinationspolyedern (einfach überkappte Tetraeder und tetragonale Pyramiden). Die Metallatome bilden gemeinsam das Motiv einer verzerrten, kubisch innenzentrierten Anordnung; die Carbo‐Liganden besetzen bei dieser Beschreibung einen Teil der Oktaederlücken. Strukturchemisch ist Pr2[Mo2C3] eng verwandt mit Er2Mo2C3 (isotyp mit Ho2Mo2C3). Beide Strukturtypen gehören zu einer (hypothetischen) Abfolge von Kristallstrukturen der gemeinsamen Summenformel RE2[T2C3]. Die physikalischen Eigenschaften der neuen ternären Verbindung entsprechen denen eines schlechten Metalls („bad metal”︁) mit lokalisierten magnetischen 4f‐Momenten, in Übereinstimmung mit dem Vorliegen von Pr3+‐Spezies. Eine detaillierte Analyse der chemischen Bindung über Zustandsdichten (DOS) und die COHP‐Methode rechtfertigt die Beschreibung der Titelverbindung als Carbomolybdat(III).
Enthalpy Landscapes of the Earth Alkaline Metal Oxides
Authors: Schön J. C. 
Published: October 2004

AbstractRecent developments in the field of solid state synthesis have given us access to synthesis conditions that range from effective negative pressures of about ‐1 GPa to high positive values exceeding 10 or even 100 GPa. Thus, it becomes necessary to explore not only the landscape of potential energy, but also the enthalpy landscapes for a wide range of pressures when attempting to predict possible crystalline modifications in a chemical system. In this work, we present the enthalpy landscapes for the earth alkaline oxides. The results are compared with experimental and theoretical studies, and we predict that it should be possible to synthesize at least some of these compounds in the so‐called 5‐5 modification.
Na8[B12(BSe3)6]: A Novel Selenoborato‐closo‐dodecaborate
Authors: Hammerschmidt A. , Döch M. , Pütz S. , Krebs B. 
Published: October 2004

AbstractSystematic studies on selenoborates containing a B12 cluster entity and alkali metal cations led to the new crystalline phase Na8[B12(BSe3)6] which consists of a icosahedral B12 cluster completely saturated with trigonal‐planar BSe3 units and sodium counter‐ions. The new chalcogenoborate was prepared in a solid state reaction from sodium selenide, amorphous boron and selenium in evacuated carbon coated silica tubes at a temperature of 850 °C. Na8[B12(BSe3)6] crystallizes in the monoclinic space group P21/c (no. 14) with a = 10.990(1) Å, b = 16.279(1) Å, c = 11.490(1), β = 117.82(1)° and Z = 2.
X‐Ray and Transmission Electron Microscopy Investigations of the New Solids In5S5Cl, In5Se5Cl, In5S5Br, and In5Se5Br
Authors: Deiseroth Hans‐Jörg , Reiner Christof , Xhaxhiu Kledi , Schlosser Marc , Kienle Lorenz 
Published: October 2004

AbstractThe compounds In5Ch5X (Ch = S, Se; X = Cl, Br) represent new mixed valence solids with indium occurring simultaneously in three different oxidation states: In+, In3+ and In2+ where the latter appears as covalently bonded dumbbells (In2)4+. Although the ionic formulation (In5Ch5X = In+ 2In3+ (In2)4+ 5Ch2— X—) is the same for all compounds, they crystallise in two structure types (In5Ch5Cl‐type: monoclinic, P21/m, Z = 2; In5Ch5Br‐type: orthorhombic, Pmn21, Z = 2). Ignoring the distribution of the halogen atoms, the anionic partial structure is very similar in both structure types. The main difference is an exchange of (In+) by (In2)4+ and vice versa on selected positions. This is possible due to the nearly identical coordination of both ions (tri‐capped trigonal prisms). HRTEM investigations show remarkable differences in the real structures of In5Ch5Cl and In5Ch5Br. In contrast to the perfectly ordered crystals of the bromides, the chlorides exhibit a variety of nanoscaled crystal defects, i.e. twinning, polylamellar intergrowth of polymorphs and lamellar intergrowth of structurally related compounds as demonstrated in In5S5Cl/In6S7. The occurrence of these defects is discussed using an appropriate structure model.