scholarly journals Darstellung und Struktur des Bicyclo-[4.4.0]-1.4.6.9-tetraazadecans C6H14N4 Preparation and Structure of Bicyclo-[4,4,0]-l,4,6,9-tetraazadecane C6H14N4

1978 ◽  
Vol 33 (8) ◽  
pp. 881-883 ◽  
Author(s):  
Wolfgang May ◽  
Hans Georg von Schnering
Keyword(s):  
Condensation Reaction ◽  
Weak Acid ◽  
Unit Cell ◽  
The Other ◽  
Formula Unit ◽  
Acid Interaction ◽  
Space Group ◽  
Bond Lengths ◽  
The Mean

Abstract By the weak acid interaction of polymeric phosphanes the condensation of ethylendi-amine yields in a small amount bicyclo-[4,4,0]-1,4,6,9-tetraazadecane C6H14N4. The compound crystallizes triclinic in the space group P1̅ with a = 841.6 pm, b - 463.6 pm, c = 529.2 pm, a= 109.05°, β= 108.35°, γ = 84.13° and Z= 1 formula unit per unit cell. The two condensed six-membered rings have chair conformations. The mean N-C bond lengths are 146.0 pm, the bridging C-C bond is 150.3 pm, whereas the other C-C bonds are 155.1 pm. Structure and condensation reaction are discussed.

(Ph4P)2 Mn2Br6 und (Ph3PCH2Ph)2Mn2I6 (Ph = C6H5) / (Ph4P)2Mn2Br6 and (Ph 3PCH2Ph)2Mn2I6 (Ph = C6H5

1988 ◽  
Vol 43 (2) ◽  
pp. 171-174 ◽  
Author(s):  
Siegfried Pohl ◽  
Wolfgang Saak ◽  
Peter Stolz
Keyword(s):  
Single Crystal ◽  
Diffraction Data ◽  
Unit Cell ◽  
Formula Unit ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
The Mean ◽  
The Difference

(Ph4P)2Mn2Br6 (1) and (Ph3PCH2Ph)2Mn2I6 (2) were prepared from the reaction of manganese dihalide with the corresponding phosphonium halide in CH2Cl2.The structures of 1 and 2 were determined from single crystal X-ray diffraction data.Both compounds crystallize in the triclinic space group P 1 with one formula unit per unit cell.1:a = 998.1(1), b = 1005.7(1), c = 1313.3(2) pm, α = 108.51(1), β = 94.25(1), γ = 100.36(1)°.2: a = 1058.6(2), b = 1236.3(2), c = 1248.4(3) pm, α = 63.53(1), β = 74.15(1), γ = 74.65(1)°.The structures of 1 and 2 exhibit discrete, dimeric anions formed by the fusion of two identical tetrahedral-like units with a common halogen-halogen edge. The mean Mn-Hal bond lengths were found to be 251.8 pm (Mn-Br) and 272.2 pm (Mn-I). The difference between the bridging and terminal Mn-Hal bond lengths is about 12-13 pm in both compounds

STEREOCHEMISTRY OF ARSENIC: PART XII. BIS(DIPHENYLARSENIC) OXIDE

1963 ◽  
Vol 41 (12) ◽  
pp. 2983-2987 ◽  
Author(s):  
W. R. Cullen ◽  
J. Trotter
Keyword(s):  
Unit Cell ◽  
The Other ◽  
Space Group ◽  
Bond Lengths ◽  
Valency Angle

Crystals of bis(diphenylarsenic) oxide are monoclinic, with four molecules in a unit cell of dimensions a = 11.48, b = 30.2, c = 5.97 Å, β = 93.8°, space group P21/n. The structure has been determined from projections along the a and c axes, using Fourier and difference syntheses. The As—O—As angle is 137°, the increase from the normal oxygen valency angle probably being a result of pπ—dπ bonding involving arsenic 4d orbitals. The As—O distance is 1.67 Å, and all the other bond lengths and angles are normal. The orientations of the substituent phenyl groups have been determined.

Die Struktur des 2.3.4.6.7.8-Hexamethyl-2.3.4.6.7.8-hexaphosphabicyclo- [3.3.0] octans (PMe)6C2H2 / The Structure of 2,3,4,6,7,8-Hexamethyl-2,3,4,6,7,8-hexaphosphabicyclo[3,3,0]octane (PMe)6C2H2

1978 ◽  
Vol 33 (7) ◽  
pp. 698-701 ◽  
Author(s):  
Hans-Georg von Schnering ◽  
Wolfgang May
Keyword(s):  
Chair Conformation ◽  
Molecular Packing ◽  
Unit Cell ◽  
Methyl Groups ◽  
Trans Conformation ◽  
Space Group ◽  
Bond Lengths ◽  
Bicyclic System ◽  
The Mean ◽  
Independent Molecules

Abstract One of the diastereomeres of 2,3,4,6,7,8-hexamethyl-2,3,4,6,7,8-hexaphosphabicyclo-[3,3,0]octane (PMe)6C2H2 crystallizes in the space group P21/n with four molecules per unit cell. Two independent molecules are nearly identical in shape but differ by inter-molecular packing. The five-membered rings have a skew chair conformation with all exocyclic methyl groups in axial positions leading to a staggered all-trans conformation of the bicyclic system. The mean bond lengths are P-P = 220.9 pm, P-C = 185.9 pm and C-C = 151.9 pm.

STEREOCHEMSTRY OF ARSENIC: PART III. o-PHENYLENEDIARSINE OXYCHLORIDE

1962 ◽  
Vol 40 (6) ◽  
pp. 1113-1117 ◽  
Author(s):  
W. R. Cullen ◽  
J. Trotter
Keyword(s):  
Symmetry Axis ◽  
Van Der Waals ◽  
Membered Ring ◽  
Unit Cell ◽  
The Other ◽  
Van Der Waals Interactions ◽  
Chlorine Atoms ◽  
Space Group ◽  
Bond Lengths ◽  
Aromatic Character

Crystals of o-phenylenediarsine oxychloride, C6H4As2Cl2O, are monoclinic with four molecules in a unit cell of dimensions a = 14.50, b = 8.38, c = 7.66 Å, β = 105.8°, space group C2/c. The structure has been determined from projections along the b and c axes. Each molecule is situated on a 2-fold symmetry axis and is planar except for the chlorine atoms, which lie one on either side of the plane of the other atoms. The values of the bond lengths and valency angles have been obtained. Abnormal valency angles at the arsenic and oxygen atoms are the result of their presence in the five-membered ring, and the unusual stability of the molecule in spite of these angles can be interpreted in terms of aromatic character, involving dπ–pπ bonding. The intermolecular separations correspond to normal van der Waals interactions.

Phosphaniminatokomplexe von Molybdän(V). Die Kristallstruktur von [MoCl4(NPPh3)]2 / Phosphaneiminato Complexes of Molybdenum(V). The Crystal Structure of [MoCl4(NPPh3)]2

1987 ◽  
Vol 42 (12) ◽  
pp. 1563-1566 ◽  
Author(s):  
Klaus Hosier ◽  
Frank Weller ◽  
Kurt Dehnicke
Keyword(s):  
Crystal Structure ◽  
Ir Spectra ◽  
Bond Angle ◽  
Unit Cell ◽  
Formula Unit ◽  
Double Bonds ◽  
Centrosymmetric Dimer ◽  
Space Group ◽  
Bond Lengths ◽  
Cell Dimensions

Abstract[MoCl4(NPPh3)]2 is prepared by the reaction of Mo2Cl10 with Ph3PNSiMe3 in boiling CH2Cl2 as brown paramagnetic (μeff = 1.72 B.M. at 20 °C) crystals, which contain ~2 mol CH2Cl2 per formula unit. With PPh4Cl the yellow complex PPh4[MoCI3(NPPh3)] · CH2Cl2 is formed. The IR spectra are recorded and discussed. [MoCl4(NPPh3)]2 crystallizes monoclinically in the space group P21/n with two formula units per unit cell (3146 observed independent reflexions, R = 0.046). The cell dimensions are a = 981.6; b = 1401.7; c = 1743.1 pm; β = 101.15°. The complex is centrosymmetric dimer showing MoCl2Mo bridges with Mo-Cl bond lengths of 244 and 278 pm. respectively. The Mo=N = P axis is nearly linear (bond angle 168.5°) with bond lengths MoN = 172 pm and PN = 166 pm. which correspond to double bonds.

Crystal and molecular structure of dodecamethylcyclohexaphosphazene, (NPMe2)6

1977 ◽  
Vol 55 (17) ◽  
pp. 3118-3123 ◽  
Author(s):  
Richard T. Oakley ◽  
Norman L. Paddock ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Unit Cell ◽  
Weighted Mean ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
The Mean

Crystals of dodecamethylcyclohexaphosphazene are triclinic, a = 13.898(1), b = 8.690(1), c = 10.790(1) Å, α = 109.84(1), β = 92.01(1), γ = 106.39(1)°, Z = 2, space group [Formula: see text]. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.034 and Rw of 0.042 for 4217 reflections with I ≥ 3σ(I). The unit cell contains two independent centrosymmetric molecules which are virtually identical. The 12-membered rings have the 'double tub' conformation. Bond lengths not involving hydrogen have been corrected for libration. Weighted mean bond lengths (rms deviations from the mean in parentheses) are: P—N, 1.593(6), C—P, 1.808(4), and C—H, 0.95(6) Å.

Quaternäre Strontium-Kupfer(I)-Lanthanoid(III)-Selenide mit Cer und Praseodym: SrCuCeSe3 und SrCuPrSe3, ein ungleiches Geschwisterpaar / Quaternary Strontium Copper(I) Lanthanoid(III) Selenides with Cerium and Praseodymium: SrCuCeSe3 and SrCuPrSe3, Unequal Brother and Sister

2004 ◽  
Vol 59 (9) ◽  
pp. 985-991 ◽  
Author(s):  
Sabine Strobel ◽  
Thomas Schleid
Keyword(s):  
Single Crystals ◽  
Coordination Number ◽  
Unit Cell ◽  
Structural Relationship ◽  
The Other ◽  
Space Group ◽  
Lattice Constants ◽  
The Third ◽  
Other Hand ◽  
Third Dimension

Quaternary strontium copper(I) lanthanoid(III) selenides are formed by the oxidation of elemental strontium, copper and the corresponding lanthanoid with selenium. Orange to red needle-shaped single crystals of SrCuPrSe3 and SrCuCeSe3 have been synthesized by heating mixtures of Sr, Cu, Pr / Ce and Se with CsI as a flux in evacuated silica tubes to 800°C for 7 d. Both compounds crystallize orthorhombically in space group Pnma with four formula units per unit cell, but with unlike lattice constants (a = 1097.32(6), b = 416.51(2), c = 1349.64(8) pm for SrCuPrSe3 and a = 846.13(5), b = 421.69(2), c = 1663.42(9) pm for SrCuCeSe3) and therefore different structure types. The Pr3+ cations in SrCuPrSe3 are surrounded octahedrally by six Se2− anions forming chains of edge-sharing [PrSe6]9− octahedra that are joined by common vertices. Together with [CuSe4]7− tetrahedra they form [CuPrSe3]2− layers piled up parallel (001). Between those layers the Sr2+ cations are coordinated by seven Se2− anions in the shape of capped trigonal prisms linking the structure in the third dimension. On the other hand in SrCuCeSe3 the Ce3+ cations as well as the Sr2+ cations adopt a coordination number of seven. Since the bonding distances between cerium and selenium match with those of strontium and selenium the two crystallographically independent sites of these cations are occupied statistically by Ce3+ and Sr2+ with equal ratios. Nevertheless, there is a close structural relationship between SrCuPrSe3 and SrCuCeSe3. Similar to SrCuPrSe3 where Cu+ and Pr3+ cations together with Se2− anions form [CuPrSe3]2− layers parallel (001), the Cu+ cations and [(Ce1/Sr1)Se7]11.5− polyhedra in SrCuCeSe3 build strongly puckered layers which are connected by (Ce2)3+/(Sr2)2+ cations. The copper selenium part in both compounds correlates as well, with [CuSe4]7− tetrahedra linked by common vertices to form [CuSe3]5− chains running along [010].

P3Se4I: 5-Iodo-2,3,6,7-tetraselena-1,4,5-triphosphabicyclo[221]heptan, ein neues Phosphorselenaiodid / P3Se4I: 5-Iodo-2,3,6,7-tetraselena-1,4,5-triphosphabicyclo[221]heptan, a New Phosphorus Selena Iodide

1987 ◽  
Vol 42 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Roger Blachnik ◽  
Willi Buchmeier ◽  
Claudia Schneider ◽  
Ulrike Wickel
Keyword(s):  
Bond Length ◽  
Nmr Spectra ◽  
Lattice Parameters ◽  
Monoclinic Space Group ◽  
Space Group ◽  
Bond Lengths ◽  
The Mean

P3Se4I is formed by the reaction of molten P4Se3 and I2. P3Se4I is monoclinic, space group P21/c with the lattice parameters of a = 1130.3(3) pm, b = 654.5(2) pm, c =1420.5(4) pm, β - 117.64(2)°. d = 3.87 g cm-3 and dx = 3.82 g cm-3 for Z = 4. The structure of the molecule is derived from the structure of α-or β-P4Se3I2 by the substitution of a P−I group by a Se-atom. The P−I, P−P and Se−Se bond lengths are 249.9, 219.2 and 236.9 pm. resp. The mean P−Se bond length is 225.0 pm. The molecule is stabilized by two weak intramolecular P−Se and P−I bonds, comparable to the bonding situation in α-P4Se3I2 . The 31P NMR spectra reveal a coalescence effect, due to equilibrium between two isomeric forms of the molecules.

Thiosemicarbazide complexes of mercury (II) halides

1978 ◽  
Vol 56 (19) ◽  
pp. 2526-2529 ◽  
Author(s):  
Chung Chieh ◽  
Laura P. C. Lee ◽  
Cecilia Chiu
Keyword(s):  
The Other ◽  
Free Molecule ◽  
Space Group ◽  
Bond Lengths ◽  
Strong Band ◽  
Ir And Raman ◽  
Lattice Modes ◽  
Neighboring Molecule

Dibromobis(thiosemicarbazide)mercury(II), HgBr2(tsc)2, is isostructural with dichlorobis-(thiosemicarbazide)mercury(II). The crystal is orthorhombic with a = 8.825(9), b = 8.587(11), c = 15.939(22) Å, Z = 4, space group Pbcn. Some bond lengths and angles are: Hg—Br = 2.860(4) Å, Hg—S = 2.45(1) Å, C—S = 1.76(4) Å and [Formula: see text]. In both HgCl2(tsc)2 and HgBr2(tsc)2, the configuration of the coordinated thiosemicarbazide (tsc) is the same as that of the free molecule. The ir and Raman (R) spectra for the complexes and tsc in the region 300–1600 cm−1 are very similar. The strong band at 800 (807 R) cm−1 in the tsc due to v(C—S) is shifted to 773 (796 R), 777 (796 R), and 660 (680 R) cm−1 for HgCl2−(tsc)2, HgBr2(tsc)2, and HgCl2(tsc) correspondingly. A strong band at 368 (R) cm−1 present uniquely for HgCl2(tsc) can be assigned to v(Hg—N), The halides in HgX2(tsc)2 are bonded to one mercury(II) ion and weakly bridged to a neighboring molecule with Hg … Cl = 3.250(3) Å and Hg…Br = 3.436(4) Å. As a result, two Raman bands due to Hg—X are expected. For HgCl2(tsc)2, the two Raman bands occur at 236 and 166 cm−1, whereas for HgBr2(tsc)2, one was observed at 190 cm−1 but the other was masked by lattice modes. In HgCl2(tsc), the two Hg—Cl bonds are different and bands at 220 and 190 cm−1 are assigned to v(Hg—Cl)t.

Isolation and structure of an 18-membered macrocycle containing two diselenide linkages and its precursor

2019 ◽  
Vol 75 (3) ◽  
pp. 336-341
Author(s):  
Saravanan Raju ◽  
Ray J. Butcher ◽  
Harkesh B. Singh
Keyword(s):  
Unit Cell ◽  
Amino Groups ◽  
Space Group ◽  
Macrocyclic Ring ◽  
Bond Lengths

The structures of the 18-membered diselenide-linked macrocycle 10,27-di-tert-butyl 11,28-dioxo-2,3,19,20-tetraselena-10,12,27,29-tetraazapentacyclo[28.4.0.04,9.013,18.021,26]tetratriaconta-1(30),4(9),5,7,13,15,17,21,23,25,31,33-dodecaene-10,27-dicarboxylate, C36H34N4O6Se4, and its precursor di-tert-butyl 2,2′-[diselane-1,2-diylbis(2,1-phenylene)]dicarbamate, C22H28N2O4Se2, are reported. The precusor to the macrocycle contains two tert-butyl phenylcarbamate arms connected to a diselenide group, with Se—C and Se—Se bond lengths of 1.914 (4) and 2.3408 (6) Å, respectively. The macrocycle resides on a crystallographic center of inversion in space group P\overline{1} with one molecule in the unit cell (Z′ = 1 \over 2). It contains an 18-membered macrocyclic ring with two diselenide linkages. In this macrocycle, there are two free and two protected amino groups.

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