Intermolecular Potentials from Crystal Data. V. Crystal Packing of Poly[β-(p-chlorobenzyl)-L-aspartate

1974 ◽  
Vol 7 (4) ◽  
pp. 468-480 ◽  
Author(s):  
Yi-Chang Fu ◽  
Robert F. McGuire ◽  
Harold A. Scheraga
Keyword(s):  
Crystal Packing ◽  
Crystal Data ◽  
Intermolecular Potentials

Determination of Intermolecular Potentials from Crystal Data. II. Crystal Packing with Applications to Poly(amino acids)

1971 ◽  
Vol 4 (1) ◽  
pp. 112-124 ◽  
Author(s):  
R. F. McGuire ◽  
G. Vanderkooi ◽  
F. A. Momany ◽  
R. T. Ingwall ◽  
G. M. Crippen ◽  
...  
Keyword(s):  
Amino Acids ◽  
Crystal Packing ◽  
Crystal Data ◽  
Intermolecular Potentials

1-aminoanthraquinone: Crystal data and a model of molecular packing

1998 ◽  
Vol 13 (2) ◽  
pp. 85-88 ◽  
Author(s):  
A. V. Yatsenko ◽  
V. V. Chernyshev ◽  
L. A. Aslanov ◽  
H. Schenk
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Crystal Packing ◽  
Molecular Packing ◽  
Inversion Center ◽  
Crystal Data ◽  
Powder Diffraction Data ◽  
Special Position ◽  
Cell Parameters ◽  
Packing Model

The powder diffraction data for 1-aminoanthraquinone at 295 K (P1¯, No. 2, Z=1) are given. The cell parameters found are a=8.205(1), b=8.396(1), c=3.7882(3) Å, α=93.46(1), β=92.57(1), γ=105.13(1)°. The crystal packing model is proposed giving Rb=0.095. The disordered molecule of 1-aminoanthraquinone occupies a special position on the inversion center.

Notizen: Tetraphenylphosphonium-octabromodiantimonat, (PPh4)2[Sb2Br8]. Synthese und Kristallstruktur / Tetraphenylphosphonium Octabromodiantimonate, (PPh4)2[Sb2Br8]. Synthesis and Crystal Structure

1985 ◽  
Vol 40 (4) ◽  
pp. 562-564 ◽  
Author(s):  
Abdulalah T. Mohammed ◽  
Ulrich Muller
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Raman Spectral Data ◽  
Raman Spectral ◽  
Ir And Raman

(PPh4)2[Sb2Br8] can be prepared from SbBr3 and PPh4Br in CH2Br2 or from Sb2S3, PPh4Br and HBr in 1,2-dichloroethane. Its crystal structure was de­termined with X-ray diffraction data (2764 observed reflexions, R = 0.039). Crystal data: triclinic, space group P1̄, a = 1024.9. b = 1127.1, c = 1282.4 pm, α = 111.80, β = 94.52, γ = 106.92°, Z = 1. The centrosymmetric [Sb2Br8]2- ions consist of two square pyramids sharing a basal edge. The cations are grouped to (PPh4+)2 pairs similarly as in (PPh4)2[As2Cl8]; although the latter compound has a comparable general crystal packing, it is not isotopic. IR and Raman spectral data are reported.

Low-temperature crystallization and structure determination of N-(trifluoromethyl)formamide, N-(2,2,2-trifluoroethyl)formamide and 2,2,2-trifluoroethyl isocyanide

1999 ◽  
Vol 55 (1) ◽  
pp. 70-77 ◽  
Author(s):  
G. J. Perpétuo ◽  
J. Buschmann ◽  
P. Luger ◽  
D. Lentz ◽  
D. Dreissig
Keyword(s):  
Crystal Structure ◽  
Low Temperatures ◽  
Crystal Packing ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Temperature Crystallization ◽  
Temperature Crystallization

Crystals of N-(trifluoromethyl)formamide, C2H2F3NO, (I), N-(2,2,2-trifluoroethyl)formamide, C3H4F3NO, (II), and 2,2,2-trifluoroethyl isocyanide, C3H2F3N, (III), were grown in situ on an X-ray diffractometer and analysed by single-crystal X-ray diffraction methods at low temperatures. Crystal data: (I) orthorhombic, P212121, a = 4.547 (2) Å, b = 5.947 (3) Å, c = 14.731 (9) Å, V = 398.3 (4) Å3, Z = 4, M r = 113.05, T = 143 K, D x = 1.885 Mg m−3; (II) monoclinic, P21/n, a = 4.807 (1) Å, b = 16.707 (3) Å, c = 6.708 (1) Å, β = 109.90 (1)°, V = 506.6 (2) Å3, Z = 4, M r = 127.07, T = 141 K, D x = 1.666 Mg m−3; (III) orthorhombic, P212121, a = 5.668 (2) Å, b = 9.266 (3) Å, c = 8.626 (2) Å, V = 453.0 (2) Å3, Z = 4, M r = 109.06, T = 163 K, D x = 1.599 Mg m−3. The results showed that in the crystal both formamides (I) and (II) are exclusively present in the form of the Z isomer, although measurements of solutions of (I) have shown that the E isomer prevails [Lentz et al. (1987). Angew. Chem. 99, 951–953]. In addition ab initio calculations for (I) predicted the E isomer to be the more stable one. In compound (III) the isocyanide group is staggered with respect to the trifluoroethyl group. In the crystal packing of (I) and (II) intermolecular N—H\cdotsO hydrogen bonds generate infinite chains. In (I), these chains are linked to form sheets by C—H\cdotsO contacts. In the crystal structure of (III) each isocyanide dipole is surrounded by four electronegative F atoms with intermolecular C\cdotsF contacts between 3.4 and 3.5 Å.

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