scholarly journals cyclo{[(6-Amino-6-deoxy-2,3:4,5-di-O-isopropylidene-D-galactonic acid)-(D-Phe)]2}

2006 ◽  
Vol 62 (5) ◽  
pp. o1851-o1853 ◽  
Author(s):  
Richard Bream ◽  
David Watkin ◽  
Raquel Soengas ◽  
George W. J. Fleet ◽  
Alison A. Edwards ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Rotation Axis ◽  
Asymmetric Unit ◽  
Relative Stereochemistry

Determination of the crystal structure of the title compound [systematic name: 9,25-dibenzyl-4,4,15,15,20,20,31,31-octamethyl-3,5,14,16,19,21,30,32-octaoxa-8,11,24,27-tetraazapentacyclo[27.3.0.02,6.013,17.018,22]dotriacontane-7,10,23,26-tetrone], C42H56N4O12, a cyclic tetramer, established the relative stereochemistry of its ten stereogenic C atoms; an interesting saddle-like conformation is adopted. There are two molecules in the asymmetric unit. With the exception of the phenyl and isopropylidene groups, the molecules are related by a non-crystallographic twofold rotation axis. There are varying degrees of disorder in the isopropylidene groups.

Cyclodimerization product of benzooxanorbornadiene

2007 ◽  
Vol 63 (3) ◽  
pp. o1462-o1463
Author(s):  
Alan J. Lough ◽  
Anna Allen ◽  
William Tam
Keyword(s):  
Crystal Structure ◽  
Structure Determination ◽  
Title Compound ◽  
Crystal Structure Determination ◽  
Asymmetric Unit ◽  
Relative Stereochemistry ◽  
Independent Molecules

The crystal structure determination of the title compound, (6aS*,6bR*,7R*,12R*,12aS*,12bS*)-7,12-epoxy-6a,6b,7,12,12a,12b-hexahydrodinaphtho[1,2-b;2,3-d]furan, C20H16O2, establishes the relative stereochemistry. There are four independent molecules in the asymmetric unit.

(2R,3S,4S,5R)-4-Hydroxy-3-iodo-5-methyltetrahydro-2-furylmethyl benzoate

2000 ◽  
Vol 57 (1) ◽  
pp. o58-o60
Author(s):  
Sean P. Bew ◽  
Mark E. Light ◽  
Michael B. Hursthouse ◽  
David W. Knight ◽  
Robert J. Middleton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Structure Determination ◽  
Title Compound ◽  
Crystal Structure Determination ◽  
Intermolecular Hydrogen Bonding ◽  
Compound C ◽  
Relative Stereochemistry

The crystal structure determination of the title compound, C13H15IO4, has allowed the relative stereochemistry between the tetrasubstituted C atoms on the tetrahydrofuran moiety to be confirmed. The title compound is a precursor of the ionophoric antibiotic Aplasmomycin. The compound is involved in both intra- and intermolecular hydrogen bonding, the latter link the molecules into chains running along thebaxis.

scholarly journals Bis(1,2-dimethoxyethane)-1κ2O,O′;3κ2O,O′-tetrakis(μ-1,1,1,3,3,3-hexafluoro-2-methylpropan-2-olato)-1:2κ4O:O;2:3κ4O:O-1,3-dilithium-2-magnesium

2012 ◽  
Vol 68 (8) ◽  
pp. m1106-m1106 ◽  
Author(s):  
Klaus Wurst ◽  
Michael R. Buchmeiser
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Rotation Axis ◽  
Ligand Field ◽  
Asymmetric Unit ◽  
Crystalline Powder ◽  
Bridging Ligands ◽  
White Crystalline Powder

The title compound, [Li2Mg(C4H3F6O)4(C4H10O2)2], forms as a white crystalline powder by-product of the reaction of lithium 1,1,1,3,3,3-hexafluoro-2-methyl-2-propoxide with Mo(N-2,6-Me2—C6H3)(CHCMe2Ph)(O3SCF3)2·2DME (DME is 1,2-dimethoxyethane) contaminated with MgCl2. The crystal structure of this compound contains half a molecule in the asymmetric unit, with a twofold rotation axis through the central Mg2+cation. The four 1,1,1,3,3,3-hexafluoro-2-methylpropan-2-olate ligands serve as bridging ligands connecting the Li+and Mg2+cations. The Li+cation is additionally stabilized by a DME ligand. This results in a distorted tetrahedral ligand field around both the Mg2+and Li+cations.

2,5-Dibromopyridinium hexabromidostannate(IV)

2007 ◽  
Vol 63 (3) ◽  
pp. m892-m894 ◽  
Author(s):  
Basem Fares Ali ◽  
Rawhi Al-Far
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Rotation Axis ◽  
Supramolecular Architecture ◽  
Asymmetric Unit ◽  
Intermolecular Hydrogen Bonds ◽  
Compound C ◽  
Distorted Octahedral

The asymmetric unit of the title compound, (C5H4Br2N)2[SnBr6], contains one cation and one half-anion. The anion exhibits a distorted octahedral arrangement about the Sn atom, which lies on a crystallographic twofold rotation axis. In the crystal structure, intermolecular hydrogen bonds and short Br...Br interactions cause the formation of a supramolecular architecture, in which they may be effective in the stabilization of the structure.

scholarly journals Crystal structure of bis[(R,R)-1,2-(binaphthylphosphonito)ethane]dichloridoiron(II) dichloromethane disolvate

2020 ◽  
Vol 76 (9) ◽  
pp. 1525-1527
Author(s):  
Benjamin E. Rennie ◽  
Alan J. Lough ◽  
Robert H. Morris
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Title Compound ◽  
Rotation Axis ◽  
Solvent Molecule ◽  
Octahedral Coordination ◽  
Coordination Geometry ◽  
Asymmetric Unit ◽  
Π Interactions

In the title compound (systematic name: bis{1,2-bis[12,14-dioxa-13-phosphapentacyclo[13.8.0.02,11.03,8.018,23]tricosa-1(15),2(11),3(8),4,6,9,16,18(23),19,21-decaen-13-yl]ethane}dichloridoiron(II) dichloromethane disolvate), [FeCl2(C42H28O4P2)2]·2CH2Cl2, the FeII ion lies on a crystallographic twofold rotation axis and is coordinated by four P atoms from two (R,R)-1,2-bis(binaphthylphosphonito)ethane (BPE) ligands and two Cl ligands in a distorted cis-FeCl2P4 octahedral coordination geometry. In the crystal, weak C—H...O and C—H...π interactions link the molecules into layers lying parallel to (001). A weak intramolecular C—H...O hydrogen bond is also observed. The asymmetric unit contains one CH2Cl2 solvent molecule, which is disordered over two sets of site with refined occupancies in the ratio 0.700 (6):0.300 (6).

scholarly journals Crystal structure of 1,1′-[imidazolidine-1,3-diylbis(methylene)]bis(naphthalen-2-ol)

2015 ◽  
Vol 71 (3) ◽  
pp. 258-260 ◽  
Author(s):  
Augusto Rivera ◽  
Jicli José Rojas ◽  
Jaime Ríos-Motta ◽  
Michael Bolte
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Rotation Axis ◽  
Asymmetric Unit ◽  
Compound C ◽  
Twist Conformation ◽  
Ring Motif

The crystal structure of the title compound, C25H24N2O2, at 173 K has monoclinic (C2/c) symmetry. The molecule is located on a crystallographic twofold rotation axis with only half a molecule in the asymmetric unit. The imidazolidine ring adopts a twist conformation, with a twist about the ring C—C bond. The crystal structure shows theanticlinaldisposition of the two (2-hydroxynaphthalen-1-yl)methyl substituents of the imidazolidine ring. The structure displays two intramolecular O—H...N hydrogen bonds, each forming anS(6) ring motif.

scholarly journals Crystal structure of poly[[(2,2′-bipyridine)manganese(II)]-di-μ-thiocyanato]

2014 ◽  
Vol 70 (12) ◽  
pp. m401-m402
Author(s):  
Stefan Suckert ◽  
Susanne Wöhlert ◽  
Inke Jess ◽  
Christian Näther
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
General Position ◽  
Rotation Axis ◽  
The Other ◽  
Asymmetric Unit ◽  
Thiocyanate Anion ◽  
Manganese Cation ◽  
Bipyridine Ligand

In the crystal structure of the polymeric title compound, [Mn(NCS)2(C10H8N2)]n, the MnIIcations are coordinated by one chelating 2,2′-bipyridine ligand and four thiocyanate anions (twoN- and twoS-coordinating), forming a distorted [MnN4S2] octahedron. The asymmetric unit consists of one manganese cation located on a twofold rotation axis and half of a 2,2′-bipyridine ligand, the other half being generated by the same twofold rotation axis, as well as one thiocyanate anion in a general position. The MnIIcations are linked by two pairs of μ1,3-bridging thiocyanate ligands into chains along thecaxis; because the N atoms of the 2,2′-bipyridine ligands, as well as the N and the S atoms of the thiocyanate anions, are eachcis-coordinating, these chains show a zigzag arrangement.

scholarly journals Redetermination of bis(acetylacetonato-κ2O,O′)(1,10-phenanthroline-κ2N,N′)manganese(II)

2013 ◽  
Vol 69 (11) ◽  
pp. m620-m620
Author(s):  
Stefan Suckert ◽  
Inke Jess ◽  
Christian Näther
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Rotation Axis ◽  
Asymmetric Unit ◽  
Bond Lengths ◽  
Image Plate ◽  
Phenanthroline Ligand

In the crystal structure of the title compound, [Mn(C5H7O2)2(C12H8N2)], the Mn2+cation is coordinated by one bidentate 1,10-phenanthroline ligand and two acetylacetonate anions within a slightly distorted N2O4octahedron. The asymmetric unit consists of one Mn2+cation situated on a twofold rotation axis, one half of a 1,10-phenanthroline ligand and one acetylacetonate anion. In comparison with the previous determination based on visually estimated intensities recorded on precession photographs, the current redetermination with image-plate data reveals bond lengths and angles with much higher precision.

scholarly journals 7,7′,8,8′-Tetramethoxy-4,4′-dimethyl-3,3′-bicoumarin

2009 ◽  
Vol 65 (6) ◽  
pp. o1294-o1295
Author(s):  
Hoong-Kun Fun ◽  
Samuel Robinson Jebas ◽  
Mehtab Parveen ◽  
Zakia Khanam ◽  
Raza Murad Ghalib
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Title Compound ◽  
Rotation Axis ◽  
The Other ◽  
Asymmetric Unit ◽  
Compound C ◽  
Related Part ◽  
Methoxy Groups

In the crystal structure, the title compound, C24H22O8, lies on a twofold rotation axis and the asymmetric unit comprises one half-molecule. The dihedral angle formed by the coumarin unit with the symmetry-related part is 74.78 (14)°. One of the methoxy groups attached to the coumarin unit is considerably twisted, making an angle of 87.17 (17)° with respect to the coumarin unit; the other is twisted by 0.66 (19)°. No classical hydrogen bonds are found in the sturcture; only a weak C—H...π interaction and short intramolecular O...O contacts [2.683 (2)–2.701 (2) Å] are observed.

scholarly journals Crystal structure of hydrazine iron(III) phosphate, the first transition metal phosphate containing hydrazine

2015 ◽  
Vol 71 (12) ◽  
pp. 1436-1438 ◽  
Author(s):  
Renald David
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Transition Metal ◽  
Title Compound ◽  
Rotation Axis ◽  
Three Dimensional ◽  
Metal Phosphate ◽  
Asymmetric Unit ◽  
Hydrothermal Conditions

The title compound, poly[(μ2-hydrazine)(μ4-phosphato)iron(III)], [Fe(PO4)(N2H4)]n, was prepared under hydrothermal conditions. Its asymmetric unit contains one FeIIIatom located on an inversion centre, one P atom located on a twofold rotation axis, and two O, one N and two H atoms located on general positions. The FeIIIatom is bound to four O atoms of symmetry-related PO4tetrahedra and to two N atoms of two symmetry-related hydrazine ligands, resulting in a slightly distorted FeO4N2octahedron. The crystal structure consists of a three-dimensional hydrazine/iron phoshate framework whereby each PO4tetrahedron bridges four FeIIIatoms and each hydrazine ligand bridges two FeIIIatoms. The H atoms of the hydrazine ligands are also involved in moderate N—H...O hydrogen bonding with phosphate O atoms. The crystal structure is isotypic with the sulfates [Co(SO4)(N2H4)] and [Mn(SO4)(N2H4)].

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