The crystal structure of the complex salt imidazole imidazolium perchlorate

1976 ◽  
Vol 54 (15) ◽  
pp. 2465-2469 ◽  
Author(s):  
Andrew Quick ◽  
David J. Williams

The crystal structure of imidazole imidazolium perchlorate has been determined at room temperature from three-dimensional diffractometer data, and refined by full-matrix least-squares to a final R = 0.051. The planar imidazole rings are linked by a [Formula: see text] hydrogen bond of length 2.73 Å and rotated with respect to each other about this bond by an angle of 50°. The analysis has failed to give conclusive evidence as to the position of the hydrogen atom between the two imidazoles.

1976 ◽  
Vol 54 (15) ◽  
pp. 2482-2487 ◽  
Author(s):  
Andrew Quick ◽  
David J. Williams

The crystal structure of benzimidazole benzimidazolium fluoroborate has been determined at room temperature from three-dimensional diffractometer data, and refined by block-diagonal least-squares to a final R = 0.050. The planar benzimidazole rings are inclined at 7.6° to each other and linked by a hydrogen bond of 2.787(3) Å with the proton in an asymmetric single minimum. The asymmetric siting of the hydrogen atom has produced characterising effects on the bond lengths and angles of the ring to which it is attached.


Author(s):  
E. M. Walitzi ◽  
F. Walter

AbstractThe crystal structure of the basaltic clino-amphibole magnesio-hastingsite was refined from three-dimensional photographic X-ray data by a full matrix least-squares method in the space group


1975 ◽  
Vol 53 (14) ◽  
pp. 2064-2067 ◽  
Author(s):  
Hok Nam Ng ◽  
Crispin Calvo

The structure of ferric phosphate at room temperature was refined on a Dauphiné-twinned crystal using full-matrix least-squares methods. The final R value was 0.078 for 487 symmetry-independent reflections whose intensities were corrected for twinning. The structure was found to be isotypic with AlPO4 (berlinite) with the space group P3121 and four formula units in a unit cell defined by a = 5.036(2) and c = 11.255(4) Å. The structure is also closely related to that of α-quartz with a nearly doubled c-axis because of the ordering of Fe and P atoms. The PO4 tetrahedron is almost regular with a mean P—O distance of 1.526 Å. The Fe3+ ion is tetrahedrally coordinated with an average Fe—O distance of 1.853 Å.


1990 ◽  
Vol 68 (10) ◽  
pp. 1797-1802 ◽  
Author(s):  
Henning Amt ◽  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter

The synthesis of 4,7-dicyclohexyl-2,2,5,6-tetraphenyl-1,3-dioxa-4-aza-7-azonia-2-boratacycloheptane is reported. Crystals of the compound are orthorhombic, a = 10.893(1), b = 28.072(1), c = 10.596(1) Å, Z = 4, space group P212121. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.036 and Rw = 0.043 for 2480 reflections with I ≥ 3σ(I). The molecule has a seven-membered chelate structure. The seven-membered ring, which has a twisted chair conformation, is stabilized by an intramolecular [Formula: see text] hydrogen bond. Bond lengths O—B = 1.468(4) and 1.554(4), C—B = 1.621(5) and 1.626(4) Å are consistent with moderately strong binding of the diphenylboron moiety by the O,O-chelating ligand. Keywords: crystal structure, organoboron compound, boron compound.


1980 ◽  
Vol 58 (7) ◽  
pp. 664-668 ◽  
Author(s):  
Rosemary C. E. Durley ◽  
William L. Waltz ◽  
Beverly E. Robertson

Crystals of [Pt(Et4dien)I]I, where Et4dien = (C2H5)2NC2H4NHC2H4N(C2H5)2, have been prepared. A three dimensional crystal structure analysis has been carried out in a monoclinic unit cell having a = 12.565(8), b = 7.576(6), c = 21.040(15) Å, β = 91.12(2)° and space group P21/c, Z = 4. Full-matrix least-squares using 1982 independent, observed reflections converged at R = 0.067. The platinum atom has square-planar co-ordination. The orientation of the four ethyl groups with respect to the plane of the ligand is similar to that observed in related molecules, in spite of a lack of similarity of the molecular packing. The iodide ion appears to be hydrogen bonded to the ligand.


Author(s):  
K. G. Keramidas ◽  
G. P. Voutsas ◽  
A. Papazoglou ◽  
P. I. Rentzeperis

AbstractThe crystal structure of BiTeI has been redetermined with 1924 independent reflections, using three-dimensional intensities measured on a computer controlled Philips PW 1100 single crystal diffractometer. The structure belongs to the rhombohedral space groupThe positional and thermal parameters, with anisotropic temperature factors, were refined by full-matrix least-squares calculations to a finalEach Bi atom is six-coordinated by three Te and three I atoms at distances 3.88(5) Å and 3.05(2) Å respectively thus forming a distorted octahedron. The faces of the octahedron are two equilateral triangles (Te-Te-Te, I-I-I) with sides 4.336 Å and six isosceles triangles (three I-Te-I and three Te-I-Te) with sides I–Te 3.29(3) Å and I–I or Te–Te 4.336 Å.The octahedra are linked to each other by a common Te–I edge along the


Author(s):  
Natthaya Meundaeng ◽  
Apinpus Rujiwatra ◽  
Timothy J. Prior

The linear two-coordinate silver (I) complex [Ag(C4H2NO2S)(C4H3NO2S)] or [Ag(2-Htza)(2-tza)] is reported (2-Htza = 1,3-thiazole-2-carboxylic acid). The AgI ion is coordinated by two heterocyclic N atoms from two ligands in a linear configuration, forming a discrete coordination complex. There is an O—H...O hydrogen bond between 2-tza− and 2tzaH of adjacent complexes. The hydrogen atom is shared between the two oxygen atoms. This interaction produces a hydrogen-bonded tape parallel to the [110] direction, which is augmented through intermolecular C—H...O hydrogen-bonding interactions between the bound thiazole groups. There is a further rather long Ag...O interaction [2.8401 (13) Å, compared with a mean of 2.54 (11) Å for 23 structures in the CSD] that assembles these tapes into columns, between which there are C—H...π interactions, leading to the formation of a three-dimensional supramolecular architecture.


1977 ◽  
Vol 41 (317) ◽  
pp. 43-50 ◽  
Author(s):  
F. C. Hawthorne ◽  
H. D. Grundy

SummaryThree-dimensional counter-diffractometer data and a full-matrix least-squares method have been used to refine the crystal structure of a sub-silicic hastingsite in the space group C2/m. The chemical composition of the amphibole is with ceil parameters a = 9·8659(4), b = 18·0139(8), c = 5·3545(2)Å, and β = 105·082(1)°. Unit weights were used throughout the refinement and the final R-factor for 1263 observed non-equivalent reflections was 4.1%. The mean tetrahcdral bond length for aluminous amphiboles varies linearly with the total amount of tetrahedral A1. Curves are derived relating individual mean bond lengths with A1 occupancy. The positional disorder on the A-site of the aluminous amphiboles appears to be partly related to the amount of substitution of A1 into the T(2) tetrahedron.


1981 ◽  
Vol 59 (1) ◽  
pp. 94-99 ◽  
Author(s):  
Kenneth S. Chong ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter

The synthesis and physical properties of N,N′-ethylenebis(salicylideneiminato)chlorogallium(III) and N,N′-ethylenebis(salicylideneiminato)methylgallium(III) are described. Crystals of N,N′-ethylenebis(salicylideneiminato)chlorogallium(III) dichloromethane are monoclinic, a = 13.049(1), b = 9.525(1), c = 15.459(2) Å, β = 92.452(5)°, Z = 4, space group P21/a. The structure was solved by Patterson and Fourier syntheses and was refined by full-matrix least-squares procedures to R = 0.042 and Rw = 0.051 for 1815 reflections with I ≥ 3σ(I). The gallium atom is bonded to one chlorine atom and to the tetradentate N,N′-ethylenebis(salicylideneiminato) ligand to give a coordination geometry which is intermediate between square pyramidal and trigonal bipyramidal. Important bond lengths (corrected for libration) are: Ga—Cl, 2.228(2), Ga—O, 1.868(4) and 1.883(4), Ga—N, 2.019(6) and 2.035(5) Å. The crystal structure consists of discrete (C16H14N2O2)GaCl and CH2Cl2 molecules linked by a[Formula: see text]hydrogen bond [Formula: see text]to form complex-solvate units.


1997 ◽  
Vol 52 (4) ◽  
pp. 490-495 ◽  
Author(s):  
Stefan Horstmann ◽  
Wolfgang Schnick

Abstract (NH2)2P(S)N=P(NH2)3 has been prepared by a two step synthesis. Suitable single crystals were obtained from an acetonitrile solution in a temperature gradient between 60 °C and room temperature. The crystal structure of (NH2)2P(S)N=P(NH2)3 has been determined by single crystal X-ray methods (P21/c, a = 998.27(9) b = 762.78(8), c = 1007.70(15) pm, β = 107.340(7)°, Z = 4). In the crystal structure each hydrogen atom is subject to a hydrogen bond. Four N-H -N hydrogen bonding interactions per molecule build up a framework connecting two molecules in eight-membered rings. Each sulfur atom shows six distances N-H···S in the range of weak hydrogen bonding interactions.


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