Die Kristallstrukturen der Polytelluride [Ca(DMF)6]Te4, [Sr(15-Krone-5)2]Te4 · H2O, {[BaCl(18-Krone-6)(DMF)2]2[BaCl(18-Krone-6)(DMF) (H2O)]2(Te4)2} und [Ph3PNPPh3]2Te5 · 2 DMF

Crystal Structures of the Polytellurides [Ca(DMF)₆]Te₄, [Sr(15-Crown-5)₂]Te₄ · H₂O, {[BaCl(18-Crown-6)(DMF)₂]₂[BaCl(18-Crown-6)(DMF) (H₂O)]₂(Te₄)₂}, and [Ph₃PNPPh₃]₂Te₅ · 2 DMF The title compounds were formed by alkalimetal polytelluride solutions in dimethylformamide (DMF) in the presence of the corresponding counter ions as well as in the presence of 15-crown-5 or 18-crown-6. Single crystals were obtained upon using additional diethylether. [Ca(DMF)₆]Te₄: Space group C2/c, Z = 4, 1024 observed unique reflections, R = 0.055. Lattice dimensions at ?70°C: a = 1776.1; b = 813.0 c = 2545.9pm; β = 102.90°. The compound consists of centrosymmetric [Ca(DMF)⁶]²⁺ ions, in which the calcium ions are octahedrally coordinated by the six oxygen atoms of the DMF molecules, and chain-like Te [Sr)15-crown-5)₂]Te₄ · H₂O: Space group C2/c, Z = 4, 3322 observed unique reflections, R = 0.058. Lattice dimensions at ?70°C: a = 1450.5; b = 1407.3; c = 1660.9 pm; β = 110.22°. The compounds forms centrosymmetric cations [Sr(15-crown-5) ₂]²⁺, in which the Sr²⁺ ion is sandwich-like surrounded by the ten oxygen atoms of the crown ether molecules, and chain-like Te₄^2? ions, which are associated in the lattice forming polymeric chains. {[BaCl(18-crown-6)(DMF) ₂]₂[BaCl(18-crown-6)(DMF)· (H₂O)] ₂(Te₄)₂}: Space group P1 , Z = 1, 3189 observed unique reflections, R = 0.054. Lattice dimensions at 19°C: a = 986.1; b = 1052.8; c = 2696.4 pm; α = 89.34°; β = 88.68°; γ = 89.56°. The compound consists of chain-like Te ions without symmetry and of the two somewhat different cations [BaCl(18-crown-6)(DMF) ₂]₂²⁺, in which the Ba²⁺ ions dimerize via centroysmmetric rings. Along with the six oxygen atoms of the crown ether molecules and the oxygen atoms of the DMF molecules, the oxygen atoms of the DMF and water molecule, respectively, the Ba⁺ ions achieve coordination number ten. [Ph₃PNPPh₃]₂Te₅ · 2DMF: Space group Pc, Z = 2, 5971 observed unique reflections, R = 0.058. Lattice dimensions at 20°C: a = 20°C: a = 1085.2; b = 1287.0; c = 2715.9 pm; β = 90.19°. The compounds consists of [Ph₃PNPPh₃]₊ ions, chain-like Te₅^2? ions, and incorporate DME molecules without bonding interaction. The ₅^2? ions are associate via polymeric chains in which left- and right handed individuals are alternating.     

Formation of Ga2Te2 and M3Te3(M = Ga, In) rings from reactions of sodium ditelluroimidodiphosphinate with Group 13 halides

Metathetical reactions of Na[N(iPr2PTe)2] with Group 13 metal halides produce the telluride complexes {Ga(mu-Te)[iPr2PNiPr2PTe]}2(2) and {M(mu-Te)[N(iPr2PTe)2]}3, M = In (3) and Ga (4), which contain central Ga2Te2 and M3Te3 rings, respectively.     

M4 @Si28 (M=Al,Ga): metal-encapsulated tetrahedral silicon fullerene

It is known that silicon fullerenes cannot maintain perfect cage structures like carbon fullerenes. Previous density-functional theory calculations have shown that even with encapsulated species, nearly all endohedral silicon fullerenes exhibit highly puckered cage structures in comparison with their carbon counterparts. In this work, we present theoretical evidences that the tetrahedral fullerene cage Si(28) can be fully stabilized by encapsulating a tetrahedral metallic cluster (Al(4) or Ga(4)). To our knowledge, this is the first predicted endohedral silicon fullerene that can retain perfectly the same cage structure (without puckering) as the carbon fullerene counterpart (T(d)-C(28) fullerene). Density-functional theory calculations also suggest that the two endohedral metallosilicon fullerenes T(d)-M(4)@Si(28) (M=Al and Ga) can be chemically stable because both clusters have a large highest occupied molecular orbital-lowest unoccupied molecular orbital energy gap ( approximately 0.9 eV), strong spherical aromaticity (nucleus-independent chemical shift value of -36 and -44), and large binding and embedding energies.     

Die Kristallstruktur von (Al0,5Ga0,5)CuOAsO4 – Kupfer zwischen planarer und geschlossener Koordination

The Crystal Structure of (Al_0,5Ga_0,5)CuOAsO₄ – Copper Intermediate between Planar and Closed Coordination Single crystals of the new oxide arsenate (Al_0.5Ga_0.5)CuOAsO₄ (monoclinic, P2₁/c, a = 734.3(2) pm, b = 1024.79(9) pm, c = 563.4(2) pm, β = 99.93(1)°, Z = 4) were obtained by reaction of Al/As/Cu/Ga-alloys with oxygen. The crystal structure was determined from four-circle diffractometer data (w2R = 0.039 for 1211 F² values and 76 parameters). The structure contains [Cu₂O₆] double squares arranged in slabs perpendicular to the a axis such that a [4 + 1]-coordination of the copper atoms by oxygen atoms results which is intermediate between square-planar and square-pyramidal. Along [100] layers of corner sharing (Al/Ga)O₄ and AsO₄ tetrahedra are alternating with buckled Cu layers.     

Structure and Polymorphism of M(thd)3 (M = Al,Cr, Mn,Fe, Co,Ga, and In)

Formation, crystal structure, polymorphism, and transition between polymorphs are reported for M(thd)₃, (M = Al, Cr, Mn, Fe, Co, Ga, and In) [(thd)^– = anion of H(thd) = C₁₁H₂₀O₂ = 2, 2, 6, 6‐tetramethylheptane‐3, 5‐dione]. Fresh crystal‐structure data are provided for monoclinic polymorphs of Al(thd)₃, Ga(thd)₃, and In(thd)₃. Apart from adjustment of the M–O_k bond length, the structural characteristics of M(thd)₃ complexes remain essentially unaffected by change of M. Analysis of the M–O_k, O_k–C_k, and C_k–C_k distances support the notion that the M–O_k–C_k–C_k–C_k–O_k– ring forms a heterocyclic unit with σ and π contributions to the bonds. Tentative assessments according to the bond‐valence or bond‐order scheme suggest that the strengths of the σ bonds are approximately equal for the M–O_k, O_k–C_k, and C_k–C_k bonds, whereas the π component of the M–O_k bonds is small compared with those for the O_k–C_k, and C_k–C_k bonds. The contours of a pattern for the occurrence of M(thd)₃ polymorphs suggest that polymorphs with structures of orthorhombic or higher symmetry are favored on crystallization from the vapor phase (viz. sublimation). Monoclinic polymorphs prefer crystallization from solution at temperatures closer to ambient. Each of the M(thd)₃ complexes subject to this study exhibits three or more polymorphs (further variants are likely to emerge consequent on systematic exploration of the crystallization conditions). High‐temperature powder X‐ray diffraction shows that the monoclinic polymorphs convert irreversibly to the corresponding rotational disordered orthorhombic variant above some 100–150 °C (depending on M). The orthorhombic variant is in turn transformed into polymorphs of tetragonal and cubic symmetry before entering the molten state. These findings are discussed in light of the current conceptions of rotational disorder in molecular crystals.     

Quaternary tellurides with different valent Ge centers: Cs2Ge3M6Te14 (M = Ga, In)

New quaternary tellurides, Cs(2)Ge(3)M(6)Te(14) (M = Ga, In), were discovered by solid-state reactions. These compounds crystallize in space group P3ml (No. 164), with a = b = 8.2475(2) ?, c = 14.2734(8) ?, and V = 840.82(6) ?(3) (Z = 1) for Cs(2)Ge(3)Ga(6)Te(14) (1) and a = b = 8.5404(2) ?, c = 14.6766(8) ?, and V = 927.07(6) ?(3) (Z = 1) for Cs(2)Ge(3)In(6)Te(14) (2). The remarkable structural feature is the novel three-dimensional [Ge(3)M(6)Te(14)](2-) anionic framework made by condensed In(6)Te(14) (or Ga(6)Te(14)) layers that are connected alternately by dimeric Ge(3+)(2)Te(6) units and Ge(2+)Te(6) octahedra along the c direction. The presence of Ge centers with different oxidation states is also supported by the results of the electron localization function calculation and X-ray photoelectron spectroscopy measurement.     

Natriumoxonitridometallate(VI) von Molybdän und Wolfram,Na4MO2N2 (M = Mo,W)

Sodium Oxonitridometallates(VI) of Molybdenum and Tungsten, Na₄MO₂N₂ (M = Mo, W) MoO₃ as well as WO₃ react with an excess of NaNH₂ in autoclaves at temperatures ranging from 250°C to 750°C to yield – in contrast to Ta₂O₅ [1] – oxonitridometallates of general composition Na₄MX₄ and other products like Na₅WO₄N [2]. The compounds decompose in moist air within minutes to Na₂WO₄, Na₂MoO₄ and Na₂MoO₄ · xH₂O, respectively. The structures of the Na₄MX₄ phases were determined from single crystal X-ray diffraction data. They crystallize triclinic in the Na₄CoO₄-type structure [3] P1 , Z = 2 with the following cell constants:      

Monomere Dialkylmetallkomplexe des Typs R2M(NR′)2XR mit M = Al,Ga, In,TI; X = S,C und R,R′ = Alkyl und Silyl

Monomeric Dialkyl Metal Complexes of the R₂M(NR′)₂XR Type with M = Al, Ga, In, Tl; X = S, C and R, R′ = Alkyl and Silyl N,N′-Bis(trimethylsilyl)sulfurdiimide reacts with the trimethyl derivatives of aluminium, gallium, and indium within insertion. Hereby monomeric sulfinic acid imidamidates Me₂M(NSiMe₃)₂SMe (Me = CH₃) are formed. The lithium amidinates Li(NR′)₂CMe (R′ = i-C₃H₇ and SiMe₃) are formed likewise by insertion reactions with LiMe and the corresponding carbodiimides R′N?C?NR′ and were used in reactions with R₂MCl (M = Al to Tl) to synthesize dialkyl metal amidinates R₂M(NR′)₂CMe. The NMR (¹H and ¹³C) and the vibrational spectra (IR and Raman) are discussed and applied to describe the structure of these chelat complexes.     

(MN)nHm(M=Ga,In; n=1-4; m=1, 2)团簇的结构与稳定性

采用密度泛函理论(DFT)的B3LYP方法, 在6-31G**和Lanl2dz水平上分别对(MN)nHm(M=Ga, In; n=1-4; m=1, 2)进行了优化和振动频率计算. 得到了上述团簇的最稳定构型、H原子的结合能以及它们的能隙. 结果表明, (MN)nH(M=Ga, In; n=1-4)的基态构型均为双重态, (MN)nH2(M=Ga, In; n=1-4)的基态构型均为单重态; 当氢的个数为1时, 加在N原子上比加在M(M=Ga, In)原子上稳定, 如有N3单元, 那么加在N3单元两侧的构型是相同的, 且它是最稳定的; 当氢的个数为2时, 除n=1外, 分别加在两个N原子上的构型是最稳定的, 如有N3单元, 那么分别加在N3单元分离最远的两个N原子的构型是最稳定的. GaNH、(GaN)3H 和InNH的结合能和能隙都很大, 说明这些团簇都有很高的稳定性.     

Synthese und Eigenschaften der Di‐tert‐butylphosphide [M(PtBu2)2]2 (M = Zn,Hg) und [Cu(PtBu2)]4

Syntheses and Properties of Di‐tert‐butylphosphides [M(PtBu₂)₂]₂ (M = Zn, Hg) and [Cu(PtBu₂)]₄ The phosphides [M(PtBu₂)₂]₂ (M = Zn, Hg) and [Cu(PtBu₂)]₄ are accessible from reaction of LiPtBu₂ with ZnI₂, HgCl₂ and CuCl, respectively. [M(PtBu₂)₂]₂ (M = Zn, Hg) are dimers in the solid state. X‐ray structural analyses of these phosphides reveal that [M(PtBu₂)₂]₂ (M = Zn, Hg) contain four‐membered M₂P₂‐rings whereas [Cu(PtBu₂)]₄ features a planar eight‐membered Cu₄P₄‐ring. Degradation reaction of LiPtBu₂(BH₃) in the presence of HgCl₂ results in the dimeric phosphanylborane BH₃ adduct [tBu₂PBH₂(BH₃)]₂. X‐ray quality crystals of [tBu₂PBH₂(BH₃)]₂ (monoclinic, P2₁/n) are obtained from a pentane solution at 6 °C. According to the result of the X‐ray structural analysis, the O₂‐oxidation product of [Hg(PtBu₂)₂]₂, [Hg{OP(O)(tBu)OPtBu₂}(μ‐OPtBu)]₂, features in the solid state structure two five‐membered HgP₂O₂‐rings and a six‐membered Hg₂P₂O₂‐ring. Herein the spiro‐connected Hg atoms are member of one five‐membered and of the six‐membered ring.     

Synthese und Kristallstrukturen der Polytelluridokomplexe (PPh4)4[M2Te12] von Kupfer(I) und Silber(I)

Syntheses and Crystal Structures of the Polytellurido Complexes (PPh₄)₄[M₂Te₁₂] of Copper(I) and Silver(I) The title compounds have been prepared as black crystal needles by reactions of Na₂Te₃ with CuCl and AgNO₃, respectively, in dimethylformamide in the presence of PPh₄Br. With regard to the large cell dimensions the crystal structure determinations were done by an imaging plate instrument. (PPh₄)₄[Cu₂Te₁₂]: Space group P2₁/n, Z = 6, 51 338 detected reflections, structure determination with 14 177 unique reflections with I > 4σ(I), R = 0.081. Lattice dimensions at ? 50°C: a = 1 704.5, b = 1 694.5, c = 5 044 pm, β = 94.20°. (PPh₄)₄[Ag₂Te₁₂]: Space group P2₁/n, Z = 6, 80 811 detected reflections, structure determination with 16 092 unique reflections with I > 3σ(I), R = 0.052. Lattice dimensions at ? 50°C: a = 1 703.8, b = 1 722.9, c = 5 123 pm, β = 94.65°. The structures of the isotypic compounds consist of six symmetry independent PPh₄⁺ ions and two symmetry independent anions [M₂Te₁₂]^4?, in which the metal atoms of two (MTe₄)^?-fivering fragments are linked by a Te₄^2? chain.     

Synthese und Kristallstrukturen der Ternären Selten-Erd-Chloride NaMCl4 (M = Eu—Yb,Y)

Synthesis and Crystal Structures of the Ternary Rare Earth Chlorides NaMCl₄ (M = Eu—Yb, Y) Single crystals of NaErCl₄ were obtained from the melt of NaCl and ErCl₃ (1:1 molar ratio) by slow cooling. It crystallizes in the monoclinic crystal system (space group P2/c) with the structure of α-NiWO₄ with a = 632.24(9) pm, b = 759.78(9) pm, c = 674.2(1) pm, b? = 92.310(3)°, Z = 2. Two preparative routes to pure powder samples of the chlorides NaMCl₄ are described. At room temperature, these are found to be isotypic with NaErCl₄ (M = Tm—Yb; II) while the triclinic structure of NaGdCl₄ is adopted with M = Gd—Ho, Y (I). Phase transitions from one structure to the other are observed for all compounds. The transition temperatures decrease with decreasing size of the ion M³⁺.     

Elucidating linear and nonlinear optical properties of defect chalcopyrite compounds ZnX2Te4 (X=Al,Ga, In) from electronic transitions

We presented a theoretical study of electronic band structure of three compounds ZnAl₂Te₄, ZnGa₂Te₄ and ZnIn₂Te₄ using pseudo potential method within density functional theory. Calculated band structures show that all band gaps are direct with at Γ with values of 1.639eV for ZnAl₂Te₄, 1.026eV for ZnGa₂Te₄and 0.836eV ZnIn₂Te₄. The linear properties based on dielectric function and non-linear optical properties based on second harmonic generation (SHG) were computed. The origin of four critical points (peaks) determined from the second derivative of the imaginary part of the dielectric function is elucidated. The use of individual k-points and individual combination of valence and conduction bands dependent matrix of the dielectric function and the nonlinear optical susceptibility allowed to a precise determination of inter band optical transitions. Indeed, inter-band analysis shows the high intensity of non-linear effect compared to linear effect. Moreover, non-linear inter-band optical transitions involve lower valence bands and higher conduction bands.     

Die Bildung von D88-Phasen zwischen 4a-Metallen und Al,Ga, In und Sb

Zusammenfassung Eine systematische Suche nach Verbindungen mit D8₈ (Mn₅Si₃)-Struktur in den Systemen von Ti, Zr und Hf mit Al, Ga, In und Sb ergab drei neue Phasen dieses Typs: Ti₅Ga₃, Hf₅Ga₃ und Zr₅Sb₃.     

Präparation und röntgenographische Charakterisierung der Verbindungen Ca3M2Ga2 (M = Pd,Pt) und Ca3M2Ga3 (M = Rh,Ir)

Preparation and Crystal Structures of the Compounds Ca₃Pd₂Ga₂, Ca₃Pt₂Ga₂, Ca₃Rh₂Ga₃, and Ca₃Ir₂Ga₃ The new compounds Ca₃Pd₂Ga₂, Ca₃Pt₂Ga₂, Ca₃Rh₂Ga₃, and Ca₃Ir₂Ga₃ were prepared by heating appropriate mixtures of the elements under an Argon-atmosphere. The results of the structure analysis of single crystals by means of X-ray diffraction are given in the section “Inhaltsübersicht”. Ca₃Pd₂Ga₂ and Ca₃Pt₂Ga₂ are isotypic and form the Y₃Rh₂Si₂ type structure (Pbcm), where the platinium metals have a trigonal environment consisting of Ga-atoms. The isotypic compounds Ca₃Rh₂Ga₃ and Ca₃Ir₂Ga₃ (Pbcm) form a new type of structure, which is related to the Y₃Rh₂Si₂ type with a distorted tetrahedral surrounding of Ga-atoms for Rh (resp. Ir).     

Molecular Precursors for the Phase‐Change Material Germanium‐Antimony‐Telluride,Ge2Sb2Te5 (GST)

This review provides an overview of the precursor chemistry that has been developed around the phase‐change material germanium‐antimony‐telluride, Ge₂Sb₂Te₅ (GST). Thin films of GST can be deposited by employing either chemical vapor deposition (CVD) or atomic layer deposition (ALD) techniques. In both cases, the success of the layer deposition crucially depends on the proper choice of suitable molecular precursors. Previously reported processes mainly relied on simple alkoxides, alkyls, amides and halides of germanium, antimony, and tellurium. More sophisticated precursor design provided a number of promising new aziridinides and guanidinates.     

Beiträge zur Kristallchemie der Urantelluride. II. Die Kristallstruktur des Diuranpentatellurids U2Te5

Contributions to the Crystal Chemistry of Uranium Tellurides. II. The Crystal Structure of Diuranium Pentatelluride U₂Te₅ Via chemical transport reactions with TeBr₄ as transporting agent single crystals of the title compound up to a size of 5 mm were available from the elements. The analysis by atomic emission spectrometry gave UTe_2.52(4). By X-ray single crystal structure analysis we found that U₂Te₅ crystallizes monoclinic (space group C2/m, Z = 4) with a = 3443.3(5) pm, b = 418.65(3) pm, c = 607.97(6) pm and β = 95.35(1)º in a new structure type. The layer structure is built up by bicapped trigonal prisms, one half as isolated building units, the other connected via faces as fourfold capped biprisms. A structural relationship of diuranium pentatelluride to the adjacent phases in the phase diagram U? Te can be expressed by the formulation as UTe₂ · UTe₃.     

Theoretical study of M(+)-RG complexes (M = Ga, In; RG = He-Rn)

We present potential energy curves calculated at the CCSD(T) level of theory for Ga(+)-RG and In(+)-RG complexes (RG = He-Rn). Spectroscopic parameters have been derived from these potentials and compared to previously calculated parameters for the Al(+)-RG and Tl(+)-RG complexes. Additionally, for some cases, we compare these parameters with those obtained from electronic spectroscopic studies on excited states of the neutral species, arising from atomic-based d ← p excitations. The Ga(+)-RG and In(+)-RG potentials have also been used to calculate the transport coefficients for M(+) traveling through a bath of RG atoms.     

Synthese und Kristallstrukturen der Polyselenidokomplexe (PPh4)6[M(Se4)2]2[WSe4] · DMF mit M = Zink und Quecksilber

Syntheses and Crystal Structures of the Polyselenido Complexes (PPh₄)₆[M(Se₄)₂]₂[WSe₄] · DMF with M = Zinc and Mercury The title compounds have been prepared by the reactions of the acetates of zinc and mercury, respectively, with excess (PPh₄)₂ WSe₄ in boiling dimethylformamide, forming black-red single crystals. According to the X-ray structure determinations both compounds crystallize isotypically in the space group 12/a with four formula units per unit cell. (PPh₄)₆[Zn(Se₄)₂]₂[WSe₄] · DMF: a = 2888.1(6), b = 1740.3(2), c = 2893.9(4) pm, β = 90.47(1)°. 3230 observed unique reflections, R = 0.009. (PPh₄)₆[Hg(Se₄)₂]₂[WSe₄] · DMF: a = 2891.8(5), b = 1738.0(4), c = 2920.1(5) pm, β = 90.29(2)°. 2978 observed unique reflections, R = 0.115%. The compounds consist of PPh₄⁺ ions, spirocyclic octaseleno metallates [M(Se₄)₂]^2?, tetrahedral WSe₄²-ions, and disordered DMF Molecules.