Sr3Al2Ge4, Ca10Al6Ge9 und Ca20Al6Ge13. Neue Aluminium-Germanide / Sr3Al2Ge4, Ca10Al6Ge9 and Ca20Al6Ge13. New Aluminium Germanides

2007 ◽  
Vol 62 (8) ◽  
pp. 1071-1082 ◽  
Author(s):  
Marco Wendorff ◽  
Caroline Röhr
Keyword(s):  
Small Deviation ◽  
Multiple Bond ◽  
Ternary Systems ◽  
Monoclinic Space Group ◽  
Band Structure Calculation ◽  
Total Density ◽  
Space Group ◽  
The One ◽  
Total Density Of States ◽  
Bond Character

In the ternary systems Ca-Al-Ge and Sr-Al-Ge three germanides with new structure types have been synthesized from stoichiometric ratios of the elements. Their crystal structures were determined using single crystal X-ray data. In the structure of Sr3Al2Ge4 (monoclinic, space group C2/m, a = 1267.6(4), b = 416.2(2), c = 887.4(3) pm, β = 110.37(2)°, Z = 2, R1 = 0.0354) Al-Ge sheets with Al in tetrahedral (i. e. Al−) and Ge in threefold ψ-tetrahedral (i. e. Ge−) coordination against Ge are present. Thus, the compound can be classified as an electron precise Zintl phase. This finding is verified by the result of a band structure calculation (within the FP-LAPW approach), that shows a distinct minimum of the total density of states at the Fermi level. The structure of Ca10Al6Ge9 (trigonal, space group R3̅m, a = 1398.45(14), c = 2107.4(3) pm, Z = 6, R1 = 0.0613) contains complicated sheets of trigonal planar building units [AlGe3] and [AlGe4] tetrahedra. The compound Ca20[Al3Ge6]2[Ge] (hexagonal, space group P63/m, a = 1600.9(2), c = 458.48(7) pm, Z = 1, R1 = 0.0282) shows two planar trimers of [AlGe3] triangles of formula [Al3Ge6] besides isolated Ge atoms (i. e. Ge4−). The overall electron count of the latter compounds, that contain trigonal planar coordinated Al atoms and considerable multiple bond character of the Al-Ge bonds, shows a very small deviation from the Zintl concept, comparable to the one observed in other aluminium-germanides like SrAlGe.

Aluminium-Germanide der zweiwertigen Lanthanoide Eu und Yb: Synthese, Strukturchemie und chemische Bindung

2011 ◽  
Vol 66 (8) ◽  
pp. 793-812
Author(s):  
Britta Bauer ◽  
Caroline Röhr
Keyword(s):  
Alkaline Earth ◽  
Building Blocks ◽  
Structure Type ◽  
Monoclinic Space Group ◽  
Total Density ◽  
Structural Element ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Type Orthorhombic ◽  
Total Density Of States

In the course of attempts to substitute Ca by Yb and Sr by Eu in known alkaline earth Al-germanides, the four new ternary compounds Eu3Al1.8Ge2.2, Eu3 Al2Ge4, Yb2 AlGe3, and Yb17Al8Ge19 have been synthesized from mixtures of the elements and their crystal structures determined by means of single-crystal X-ray data. The two europium compounds Eu3Al1.8Ge2.2 (Ta3B4 structure type, orthorhombic, space group Immm, a = 417.68(3), b = 470.70(3), c = 1897.2(2) pm, Z = 2, R1 = 0.0439) and Eu3Al2Ge4 (Sr3Al2Ge4 structure type, monoclinic, space group C2/m, a = 1235.9(6), b = 416.8(2), c = 878.4(4) pm, β = 110.615(13)°, Z = 2, R1 = 0.0978) are isotypic with the corresponding strontium phases. After ionic decomposition, the layers [Al2- Ge4- ]6− in Eu3Al2Ge4 with four-bonded Al and three-bonded Ge atoms can be interpreted as electron-precise Zintl anions. In contrast, the planar ribbons 1∞[Al2/2Ge2Al2/2] of condensed six-membered rings in Eu3Al1.8Ge2.2 exhibit considerably shorter Al-Ge bonds and an Al-Al bond length of only 251 pm. Yb2AlGe3 (orthorhombic, space group Pnma, a = 682.20(10), b = 417.87(9), c = 1813.9(3) pm, Z = 4, R1 = 0.0415) crystallizes with the Y2AlGe3 structure type. Folded [Al2Ge2] ladders, also found in Eu3Al2Ge4 and the known compound Yb7Al5Ge8, are connected by planar cis/trans chains of Ge atoms. The total density of states calculated within the FP-LAPW|DFT band structure approach shows a distinct minimum at the Fermi level for the electron precise Zintl compound Eu3Al2Ge4, whereas π-bonding contributions are evident from the band structures of Eu3Al2Ge2 and Yb2AlGe3. In full accordance, the tDOS of both compounds exhibits no minimum at EF, small phase widths are possible for Eu3Al2Ge2 and related alkaline earth compounds, and Yb2AlGe3 is isotypic with several other more electron-rich LnIII compounds. The complicated structure of the new compound Yb17Al8Ge19 (tetragonal, space group P4/nmm, a = 1542.50(2), c = 788.285(8) pm, Z = 2, R1 = 0.0282) contains three different building blocks: distorted [Al4Ge4] heterocubane units are interconnected by four-bonded Ge atoms to form columns running along the c axis. Secondly, eight-membered rings are formed by alternating Al and Ge atoms, each being in a trigonal-planar Al/Ge coordination. The rings are terminated by Ge atoms (bonded to Ge of the ring) and linked to the first structural unit by a further Ge atom (bonded to Al of the ring). Thirdly, inside the large channels, which are formed by the packing of the eightmembered rings, Ge2 dumbbells are interspersed as a third structural element.

Neue gemischte Zinn-reiche Erdalkalimetall-Stannide – Synthese, Strukturchemie und chemische Bindung / New Mixed Tin-rich Alkaline Earth Stannides – Synthesis, Structural Chemistry and Chemical Bonding

2011 ◽  
Vol 66 (3) ◽  
pp. 245-261
Author(s):  
Marco Wendorff ◽  
Caroline Röhr
Keyword(s):  
Structural Features ◽  
Monoclinic Space Group ◽  
Total Density ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Counting Rules ◽  
New Compounds ◽  
Tin Content ◽  
Type Orthorhombic ◽  
Total Density Of States

Ternary mixed Ca/Ba-Sr pentastannides AIISn5 (AII = Ca, Sr, Ba) have been synthesized from stoichiometric mixtures of the elements or from tin-rich melts. The crystal structures of two new compounds of overall composition ASn5 (A = Sr, Ba) were determined by means of single-crystal X-ray data. The structures of both Sr0.94Ba0.06Sn5 (monoclinic, space group C2/m, a = 1762.8(11), b = 704.1(3), c = 1986(2) pm, β = 100.31(6)º, Z = 14, R1 = 0.0996) and Sr0.89Ba0.11Sn5 (orthorhombic, space group Cmcm, a = 708.1(2), b = 1770.4(8), c = 2781.6(11) pm, Z = 20 , R1 = 0.0821) are closely related and can be described by different stacking sequences of comparable nets. They both resemble the structural features of the tristannides AIISn3 in forming dimers and trimers of facesharing Sn6-octahedra, which are further connected via common corners. According to the higher tin content, the rods formed of the octahedra are interspersed by additional Sn atoms, which themselves show a bonding situation resembling the structure of elementary tin. The complex tin network formed by the strong Sn-Sn bonds alone can be regarded as a cutout of the hexagonal diamond structure. In this view, the similarities of the title compounds to the known binary stannides BaSn5 and SrSn4 become apparent. The phase widths of the latter have been investigated and shown to reach up to Sr0.37Ba0.63Sn5 (BaSn5 type, hexagonal, space group P6/mmm, a = 536.8(2), c = 695.2(3) pm, R1 = 0.0312) and Sr0.79Ca0.21Sn4 (SrSn4 type, orthorhombic, space group Cmcm, a = 461.7(3), b = 1714.1(14), c = 706.7(4) pm, Z = 4, R1 = 0.0861), respectively. The total density of states calculated for the orthorhombic pentastannide within the FP-LAPW DFT band structure approach shows a broad minimum at the Fermi level, which can be explained using the Zintl and the Wade/Jemmis electron counting rules.

scholarly journals Synthesis and crystal structure of Na4Ni7(AsO4)6

2016 ◽  
Vol 72 (5) ◽  
pp. 632-634 ◽  
Author(s):  
Rénald David
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Monoclinic Space Group ◽  
Site Symmetry ◽  
Asymmetric Unit ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
Ceramic Synthesis ◽  
The One

The title compound, tetrasodium heptanickel hexaarsenate, was obtained by ceramic synthesis and crystallizes in the monoclinic space groupC2/m. The asymmetric unit contains seven Ni atoms of which two have site symmetry 2/mand three site symmetry 2, four As atoms of which two have site symmetrymand two site symmetry 2, three Na atoms of which two have site symmetry 2, and fifteen O atoms of which four have site symmetrym. The structure of Na4Ni7(AsO4)6is made of layers of Ni octahedra and As tetrahedra assembled in sheets parallel to thebcplane. These layers are interconnected by corner-sharing between NiO6octahedra and AsO4tetrahedra. This linkage creates tunnels running along thecaxis in which the Na atoms are located. This arrangement is similar to the one observed in Na4Ni7(PO4)6, but the layers of the two compounds are slightly different because of the disorder of one of the Ni sites in the structure of the title compound.

Reaktionen von Oxovanadium-Dipicolinatokomplexen mit Benzoylhydrazin. Die Kristallstrukturen von [VO(dipic)(NH2NHC(O)Ph) · NH2NHC(O)Ph · H2O, [C(NH2)3][VO(dipic)(NHNC(O)Ph)] · 2H2O und der „blauen“ Modifikation von [VO(dipic)(H2O)2] · 2H2O / Reactions of Oxovanadium(IV) and -(V) Dipicolinato Complexes with Benzoylhydrazine. Crystal Structures of [VO(dipic)(NH2NHC(O)Ph)] · NH2NHC(O)Ph · H2O · [C(NH2)3][VO(dipic)(NHNC(0)Ph)] · 2H 2O and the “Blue” Modification of [VO(dipic)(H2O) 2] · 2 H2O

1993 ◽  
Vol 48 (2) ◽  
pp. 125-132 ◽  
Author(s):  
Angelika Sundheim ◽  
Rainer Mattes
Keyword(s):  
Multiple Bond ◽  
Resonance Spectroscopy ◽  
Space Group ◽  
Bond Lengths ◽  
Spin Resonance ◽  
Pyridine Dicarboxylic Acid ◽  
In Trans ◽  
Carbonyl Bond ◽  
Axial Site ◽  
Bond Character

AbstractThe hydrazino complex [VO(dipic)(NH2NHC(O)Ph)] · NH2NHC(O)Ph · H2O (3) has been prepared by reaction of [VO(dipic)(H2O)] · 2H2O (1) with NH2NHC(O)Ph. (dipic = dianion of pyridine dicarboxylic acid). The hydrazido(2-) complex (guanid)[VO(dipic)(NHNC(O)Ph)] · 2H2O (4) was obtained by reaction of (guanid)[VO2(dipic)]·2H2O and NH2NHC(O)Ph. During the course of this reaction a terminally bonded oxygen atom is abstracted from the vanadium(V) center. 1, 3 and 4 have been characterized by X-ray single crystal diffraction, infrared, Raman and electron spin resonance spectroscopy.In 1 vanadium is six-coordinate, with the nitrogen atom of the dipic ligand in trans position to the oxo group. The two water molecules are also ligated in mutual trans positions. Vanadium is also six-coordinate in 3 and 4. In both, the dipic ligand is cis oriented with respect to the terminal oxo group. In 3 benzoylhydrazine, and in 4 the hydrazido(2 -) species NHNC(O)Ph act as N,O-chelate ligands, donating their NH2-, respectively NH-group to the remaining equatorial site and their CO-group to an axial site. The V - NH2(213.1(4) pm) and V - NH (190.5(2) pm) bond lengths differ considerably, indicating multiple bond character for the latter. In 3 the V -O(oxo) and V-O (carbonyl) bond lengths are 160.1(4) and 219.1(3) pm, and in 4 160.8(2) and 211.9(2) pm, respectively. Crystal data for 1: space group P 1̄, a = 656.2(2), b = 913.2(3), c - 1075.2(2) pm, α= 111.44(2), β = 100.16(2), γ = 94.81(3)°, Z = 2; 3: space group P1̄, a = 801.4(2), b = 1188.7(11), c = 1353.5(12) pm, α = 72.02(7), β = 88.31(7), γ = 70.60(7)°, Z = 2; 4: space group P 1̄, a = 1018.2(5), b = 1222.5(6), c = 1683.2(6) pm, α = 80.02, β = 89.95, γ = 78.73°, Z = 4.

scholarly journals Pressure Prediction of Electronic, Anisotropic Elastic, Optical, and Thermal Properties of Quaternary (M2/3Ti1/3)3AlC2(M = Cr, Mo, and Ti)

2016 ◽  
Vol 2016 ◽  
pp. 1-18 ◽  
Author(s):  
Liang Sun ◽  
Yimin Gao ◽  
Yangzhen Liu ◽  
Guoliang Wang ◽  
Yiran Wang ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Ambient Pressure ◽  
Relative Volume ◽  
Ultraviolet Region ◽  
Total Density ◽  
Covalent Bonds ◽  
Optical Functions ◽  
Anisotropic Elastic ◽  
The One ◽  
Total Density Of States

The electronic, mechanical, anisotropic elastic, optical, and thermal properties of quaternary (M2/3Ti1/3)3AlC2(M = Cr, Mo, and Ti) under different pressure are systematically investigated by first-principles calculations. The bonding characteristics of these compounds are the mixture of metallic and covalent bonds. With an increase of pressure, the heights of total density of states (TDOS) for these compounds decrease at Fermi level. The highest volume compressibility among three compounds is Mo2TiAlC2for its smallest relative volume decline. The relative bond lengths are decreasing when the pressure increases. The bulk and shear modulus of the one doped with Cr or Mo are larger than those of Ti3AlC2with pressure increasing. With an increase of pressure, the anisotropy of these compounds also increases. Moreover, Mo2TiAlC2has the biggest anisotropy among the three compounds. The results of optical functions indicate that the reflectivity of the three compounds is high in visible-ultraviolet region up to ~10.5 eV under ambient pressure and increasing constantly when under pressure. Mo2TiAlC2has the highest loss function. The calculated sound velocity and Debye temperature show that they all increase with pressure.CVof the three compounds is also calculated.

Darstellung und Kristallstruktur des Niob-(triphenylphosphinimino)tetrachlorids, Nb [NP (C6 H5 )3] Cl4, einer Verbindung mit einer Niob-Stickstoff-Mehrfachbindung /Preparation and Crystal Structure of Niobium(triphenyl-phosphineimino)tetrachloride, Nb[NP(C6H5)3]Cl4, a Compound with a Niobium Nitrogen Multiple Bond

1979 ◽  
Vol 34 (9) ◽  
pp. 1199-1202 ◽  
Author(s):  
Hans Bezier ◽  
Joachim Strahle
Keyword(s):  
Crystal Structure ◽  
Multiple Bond ◽  
Monoclinic Space Group ◽  
Double Bonds ◽  
Triphenyl Phosphine ◽  
Chlorine Atoms ◽  
Space Group ◽  
Cl Atoms ◽  
Centrosymmetric Dimers ◽  
Yellow Compound

AbstractNb[NPPh3]Cl4 can be prepared by reacting NbCl4N3 with PPh3 in 1,2 dichloro ethane. The crystalline, yellow compound crystallizes in the monoclinic space group C2/c. The crystal structure consists of eight molecules, which are linked together via bridging chlorine atoms to centrosymmetric dimers. Thereby the niobium atoms obtain a sixfold coordination by one N and five Cl atoms. The triphenyl phosphine imine ligand is bound to niobium by its N atom. The approximate linearity of the resulting Nb-N-P group (angle Nb-N-P = 171°) and the distances Nb-N - 178 pm and N-P =164 pm can be interpreted by an sp hybridized N atom and double bonds to both the Nb and P atom.

Sr14[Al4]2[Ge]3: Eine Zintl-Phase mit isolierten [Ge]4–- und [Al4]8–-Anionen / Sr14[Al4]2[Ge]3: A Zintl Phase with Isolated [Ge]4− and [Al4]8− Anions

2007 ◽  
Vol 62 (10) ◽  
pp. 1227-1234 ◽  
Author(s):  
Marco Wendorff ◽  
Caroline Röhr
Keyword(s):  
Structure Type ◽  
Structure Calculation ◽  
Band Structure Calculation ◽  
Total Density ◽  
Zintl Phase ◽  
New Members ◽  
X Ray ◽  
Formal Charge ◽  
Ternary Intermetallic Compound ◽  
Total Density Of States

The new ternary intermetallic compound Sr14[Al4]2[Ge]3 was synthesized from stoichiometric ratios of the elements. The crystal structure (trigonal, space group R3̅, a = 1196.58(2), c = 4010.33(7) pm, Z = 6, R1 = 0.0574) was determined using single crystal X-ray data. The structure contains two crystallographically independent tetrahedral [Al4] anions with Al-Al distances in the range from 269.7 to 273.6 pm. Taking into account the Zintl concept and the isosteric analogy to white phosphorus, their formal charge is−8. Both of these tetrahedra are surrounded by 16 Sr cations. The three isolated Ge4− anions per formula unit (isosteric to the noble gases) are coordinated by nine Sr cations. According to the ionic description Sr14[Al4]2[Ge]3̅↦14Sr2+ +2[Al4]8− +3[Ge]4− the title compound is an electron-precise Zintl phase. This interpretation is supported by the results of a FP-LAPW band structure calculation, which show a distinct minimum of the total density of states at the Fermi level. Attempts to synthesize the analogous compounds in the systems Sr-Ga-Ge and Ca-Ga-Ge resulted in the formation of new members of the Ca11Ga7 structure type family. In the case of Ca-Al-Ge only the stable binary border compounds Ca2Ge and CaAl2 were formed in respective experiments.

Reaktionen von Mehrfachbindungssystemen mit dem 1.2.4-Trithia-3.5-diborolan-Ring -Eine strukturelle Richtigstellung / Reactions of Multiple-Bond-Systems with the 1,2,4-Trithia-3,5-diborolane Ring - A Structural Correction

1983 ◽  
Vol 38 (10) ◽  
pp. 1182-1191 ◽  
Author(s):  
Mathias Noltemeyer ◽  
George M. Sheldrick ◽  
Carl Habben ◽  
Anton Meller
Keyword(s):  
Ir Spectra ◽  
Multiple Bond ◽  
Monoclinic Space Group ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
C Nmr

The reaction of the 1,2,4-trithia-3,5-diborolane system with alkynes does not give 1,3,2-dithiaboroles, as suggested earlier [1, 2], but the previously unknown 1,2,3-dithiaboroles. With organic isocyanates and di-isopropylcarbodiimide, 1,2-dithia-3-bora-4-azacyclopentanones-( 5) and -thiones-(5), respectively, were isolated. The latter systems are isomers of the 5-methyl-1,4-dithia-2-aza-5-boracyclopentanones-(3) and -thiones-(3), which had been previously assumed as reaction products. The structures of 3-diethylamino-4,5- diphenyl -1,2,3 -dithiaborole - (4) (18), 3-(2,6-dimethylphenyl)-amino-4,5-diethyl-1,2,3-dithiaborole-( 4) (31) and 2-diphenylamino-1,3,2-dithiaborole-(4) (32) have been determined by X-ray diffraction. 18 is monoclinic, space group P21, a = 627.8(2), b = 1218.8(2), c = 1158.6(3) pm, β = 97.35(2)° and Z = 2. 31 is monoclinic, space group C2/c, a = 1475.9(5), b = 898.6(3), c = 2434.7(9) pm, β = 102.71(3)° and Z = 8. 32 is orthorhombic, space group Aba 2, a = 2557.3(8), b = 1748.5(5), c = 935.2(2) pm, Z = 12. 1H, 11B, 13C NMR, mass and IR spectra are also reported and discussed.

A New Host Lattice Built of the Werner-Type Copper(I,II) Cyanide Complex Involving a Macrocyclic Ligand

1998 ◽  
Vol 63 (5) ◽  
pp. 622-627 ◽  
Author(s):  
Hidetaka Yuge ◽  
Takayoshi Soma ◽  
Takeshi Ken Miyamoto
Keyword(s):  
Macrocyclic Ligand ◽  
Host Lattice ◽  
Macrocyclic Complex ◽  
Monoclinic Space Group ◽  
Cyanide Complex ◽  
New Host ◽  
Space Group

Crystals of a new clathrate [CuII(hmtd)CuI(CN)3]·CH2Cl2 were afforded from a Me2CO-EtOH-CH2Cl2 solution of a macrocyclic complex CuII(hmtd)CuI(CN)3·2 H2O (hmtd = 5,7,7,12,14,14-hexamethyl- 1,4,8,11-tetraazacyclotetradeca- 4,11-diene). It crystallizes in the monoclinic space group P21/n, a = 7.936(5), b = 18.717(4), c = 17.783(6) Å, β = 98.55(4)°, Z = 4, R = 0.0558 for 1 870 reflections. Unprecedentedly, only one of the three nitrogen-ends of a CuI(CN)3 moiety is coordinated to the square-pyramidal Cu(II) center. The guest CH2Cl2 molecules are captured in the channel between the potlid-shaped [CuII(hmtd)CuI(CN)3] molecules.

scholarly journals Molekül- und Kristallstruktur von 1.1-Dimethylsilylentitanocendichlorid, (CH3)2Si(C5H4)2TiCl2 / Molecular and Crystal Structure of l,r-Dimethylsilylene Titanocene Dichloride, (CH3)2Si(C5H4)2TiCl2

1981 ◽  
Vol 36 (10) ◽  
pp. 1208-1210 ◽  
Author(s):  
Hartmut Köpf ◽  
Joachim Pickardt
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Structure Determination ◽  
Titanocene Dichloride ◽  
Molecular And Crystal Structure ◽  
Monoclinic Space Group ◽  
Crystal Data ◽  
Space Group ◽  
X Ray ◽  
Structural Dimensions

Abstract The molecular structure of the bridged [1]-titanocenophane 1,1'-dimethylsilylene titanocene dichloride, (CH3)2Si(C5H4)2TiCl2, has been investigated by an X-ray structure determination. Crystal data: monoclinic, space group C2/c, Z = 4, a = 1332.9(3), 6 = 988.7(3), c = 1068.9(3) pm, β = 113.43(2)°. The results are compared with the structural dimensions of similar compounds: 1,1'-methylene titanocene dichloride, CH2(C5H4)TiCl2, with the unbridged titanocene dichloride, (C5H5)2TiCl2 and the ethylene-bridged compound (CH2)2(C5H4)2TiCl2

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