Cobalt(III) Complexes of the 10-Membered Macrocycle 1,4,7-Triazacyclodecane. The Structure of trans-Bis(1,4,7-triazacyclodecane)cobalt(III) Perchlorate

1993 ◽  
Vol 46 (12) ◽  
pp. 1955 ◽  
Author(s):  
TW Hambley ◽  
TW Hambley ◽  
GH Searle ◽  
GH Searle
Keyword(s):  
Crystal Structure ◽  
Membered Ring ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Lengths

The crystal structure of trans-[Co( tacd )2](ClO4)3 has been determined by X-ray diffraction methods and refined to a residual of 0.054 for 2477 independent observed reflections. The crystals are monoclinic, P 21/c, a 18.627(2), b 9.3438(5), c 16.057(2)Ǻ, β 119.45(2)°. Two complex cations are located at centres of symmetry and the ligands adopt λ,δ,chair conformations. Bond lengths from cobalt to nitrogen atoms in the six- membered ring (average 1.995 Ǻ) are significantly longer than those only associated with five- membered rings (average 1.961 Ǻ).

scholarly journals Dibrom(dimethylamino)alan und Diiod(dimethylamino)alan. Darstellung und Kristallstruktur / Dibromo(dimethylamino)alane and Diiodo(dimethylamino)alane. Preparation and Crystal Structure

1978 ◽  
Vol 33 (1) ◽  
pp. 43-46 ◽  
Author(s):  
Aftabuddin Ahmed ◽  
Wolfgang Schwarz ◽  
Heinz Hess
Keyword(s):  
Crystal Structure ◽  
Membered Ring ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Lengths

Abstract The title compounds were prepared by reaction of dimethylaminoalane with mercury - (II) dibromide and diiodide, respectively, and investigated by X-ray diffraction. Both compounds build structures isotype with that of dichloro(dimethylamino)alane. The molecules exist as dimers with a planar four-membered ring of alternating aluminium and nitrogen atoms. These atoms are four-coordinated. The following bond lengths are found: Al-N 1.94 and 1.95 Å, Al-Br 2.26 Å, Al-I 2.49 Å, N-C 1.50 and 1.55 Å.

Synthesis, crystal structure and molecular conformation of (±)-1-oxoferruginol and (±)-shonanol

2004 ◽  
Vol 219 (10) ◽  
Author(s):  
Swastik Mondal ◽  
Monika Mukherjee ◽  
Arnab Roy ◽  
Debabrata Mukherjee
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Diffraction Data ◽  
Molecular Conformation ◽  
Membered Ring ◽  
Methyl Groups ◽  
Single Bond ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Structures

Abstract(±)-1-oxoferruginol and (±)-shonanol, two potential intermediates in the synthesis of tricyclic diterpenoid ferruginol, have been prepared and crystal structures of the compounds have been investigated using single-crystal X-ray diffraction data. The methyl groups of the isopropyl moiety in (±)-shonanol are disordered over two positions with occupation factors 0.65(1) and 0.35(1), respectively. Although the chemical structures of two compounds are very similar, a C—C single bond in the terminal six-membered ring of (±)-1-oxoferruginol is replaced by a C=C bond in (±)-shonanol, the quantitative isostructurality index calculations indicate that the structures are not isostructural. Intermolecular O—H…O hydrogen bonds between pairs of molecules in the compounds related by center of inversion lead to characteristic dimers forming R

Pyridin-Addukte von Cyclothiazeno-Vanadiumdichlorid Die Kristallstruktur von [VCl2(N3S2)(C5H5N)] / Pyridine Adducts of Cyclo-thiazeno Vanadium Dichloride The Crystal Structure of [VCl2(N3S2)(C5H5N)]

1985 ◽  
Vol 40 (12) ◽  
pp. 1631-1637 ◽  
Author(s):  
Ruth Christophersen ◽  
Paul Klingelhöfer ◽  
Ulrich Müller ◽  
Kurt Dehnicke
Keyword(s):  
Crystal Structure ◽  
Ir Spectra ◽  
Chlorine Atom ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Trigonal Bipyramidal ◽  
Independent Molecules

Abstract The pyridine complexes of cyclo-thiazeno vanadium dichloride, [VCl2(N3S2)py] and [VCl2(N3S2)(py)2] were synthesized by reactions of polymeric VCl2(N3S2) with varying amounts of pyridine in CH2Cl2. The compounds were characterized by their IR spectra as well as by their 51V NM R spectra. The crystal structure of [VCl2(N3S2)(C5H5N)] was determined by means of X-ray diffraction (1582 independent observed reflexions, R = 0.031). Crystal data: orthorhombic, space group Pnma, a = 1372, b - 2261, c - 1068 pm, Z = 12. In the lattice there are two monomeric, crystallographically independent molecules [VCl2(N3S2)(C5H5N)], which differ only slightly. The vanadium atoms have a trigonal bipyramidal coordination with the N atom of the pyridine molecule and one chlorine atom in apical positions, and with one chlorine atom and the N atoms of the cyclo-thiazeno ligand in equatorial positions. The VN bond lengths of the planar VN3S2 ring of 174 pm correspond to double bonds

The X-Ray Crystal Structure of 1,2-3,4-Di-O-isopropylidene-4-C-methylthiomethoxy-β-L-arabino-hexoseptanos-5-ulose

1990 ◽  
Vol 43 (12) ◽  
pp. 2083 ◽  
Author(s):  
DC Craig ◽  
VJ James ◽  
JD Stevens
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Membered Ring ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray

The crystal structure of the title compound (1) has been determined by X-ray diffraction. Crystals of (1) are orthorhombic, space group P21212 with a 11.425(1), b 24.916(1), c 5.8952(3)Ǻ, Z 4. Refinement on 1675 observed reflections measured with Cu Kα radiation converged at R 0.034. The seven- membered ring adopts a boat conformation in which the pseudo plane of symmetry passes through the ring oxygen.

Pentamethylcyclopentadienyl-Vanadium Complexes Containing Halogeno- and Oxo-Ligands

1987 ◽  
Vol 42 (12) ◽  
pp. 1520-1526 ◽  
Author(s):  
Max Herberhold ◽  
Walter Kremnitz ◽  
Markus Kuhnlein ◽  
Manfred L. Ziegler ◽  
Karl Brunn
Keyword(s):  
Crystal Structure ◽  
Mass Spectra ◽  
High Yield ◽  
Vanadium Complexes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Lengths ◽  
Oxygen Bond ◽  
Single Bonds ◽  
Oxo Ligands

AbstractA simple and high-yield preparation of the pentamethylcyclopentadienyl vanadium(IV) trihalides Cp*VX3 (X = CL, Br, I) from Cp*V(CO)4 as well as their conversion into the oxo-vanadium(V) compounds Cp*VOX2 (X = CL, Br) and [Cp*VOX]2(μ-O) (X = CL, Br, I) are described. The equilibrium between the two fluoride species Cp*VOF2 and [Cp*VOF]2(μ-O) has also been investigated. The complexes are characterized by their NMR (51V, l3C, 1H), IR, and mass spectra. The crystal structure of the binuclear chloro-oxo complex [Cp*VOCl]2(μ-O) has been determined by X-ray diffraction. The molecules contain two [Cp*VOCl] units combined via a bent oxo bridge (V-O-V angle of 142.2(2)°). The vanadium-oxygen bond lengths are 157.6(8) and 179.4(1) pm for the terminal and the bridging oxo ligands, respectively, corresponding to double and single bonds.

Lewis-Base Adducts of Group 11 Metal(I) Compounds. LIX. Crystal Structure Determinations of Tetrakis(trimethylphosphine)copper(I) Halides and Tetrakis(triphenylphosphine)-copper(I) and -silver(I) Hexafluorophosphates

1990 ◽  
Vol 43 (10) ◽  
pp. 1697 ◽  
Author(s):  
GA Bowmaker ◽  
PC Healy ◽  
LM Engelhardt ◽  
JD Kildea ◽  
BW Skelton ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Structures ◽  
Lewis Base ◽  
X Ray Diffraction ◽  
Coordination Environment ◽  
X Ray ◽  
Bond Lengths ◽  
Cu Complex ◽  
Structure Determinations

The crystal structures of [Cu(Pme3)4]X (X = Cl , Br, I) and of [M(PPh3)4] [PF6] (M = Cu, Ag) have been determined by single-crystal X-ray diffraction methods at 295 K. The former compounds contain nearly tetrahedral [Cu(PMe3)4]+ ions on sites of m symmetry with mean Cu-P bond lengths of 2.270, 2.271 and 2.278 Ǻ for X = Cl , Br and I respectively. The latter compounds contain [M(PPh3)4]+ ions on sites of 3 symmetry. In the M =Ag complex the coordination environment is close to tetrahedral, but in the M =Cu complex the length of the axial Cu-P bond [2.465(2)Ǻ] is significantly shorter than that of the off-axis bonds [2.566(2)Ǻ]. Possible reasons for this are discussed.

Brom- und Chlorthionitrenkomplexe des Rheniums. Die Kristallstruktur von (PPh4)2 [ReBr4(NS)(NSBr)]·CH2Br2 Bromo- and Chlorothionitrene Complexes of Rhenium The Crystal Structure of (PPh4)2[ReBr4(NS)(NSBr)]·CH2Br2

1986 ◽  
Vol 41 (7) ◽  
pp. 825-830 ◽  
Author(s):  
Hans-Günter Hauck ◽  
Wolfgang Willing ◽  
Ulrich Müller ◽  
Kurt Dehnicke
Keyword(s):  
Crystal Structure ◽  
Ir Spectra ◽  
Ring Cleavage ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Pyridine Complex ◽  
Subsequent Addition

AbstractThe thionitrosyl-halothionitrene com pounds (PPh4)2[ReX4(NS)(NSX)]·2 CH2X2, X = Cl or Br, are obtained by nucleophilic ring cleavage of the Re(N2S2) rings of complexes [ReX4(N2S2)]⊖ with PPh4X in CH2X2. (AsPh4)2[ReCl4(NS)(NSCl)] · CH2Cl2 can also be obtained by the reaction of [ReCl4(NSCl)(POCl3)] with S(NSiMe3)2 and subsequent addition of AsPh4Cl. The pyridine complex [ReBr2(NS)(NSBr)(NC5H5)2] · CH2Br2 forms by bromination of the corresponding chloro compound with Me3SiBr. The IR spectra are reported. The crystal structure of (PPh4)2[ReBr4(NS)(NSBr)] · CH2Br2 was determ ined by X-ray diffraction (4158 independent observed reflexions, R = 0.059). Crystal data: a = 1039.7, b - 1232.5, c - 2158.4 pm, α = 81.59, β = 87.05, γ = 77.06°, Z = 2, space group P1̄. The compound consists of PPh4⊕ ions, CH2Br2 molecules, and anions [ReBr4(NS)(NSBr)]2⊖ in which the rhenium atoms are coordinated by four bromine atoms, one thionitrosyl and one brom othionitrene group. The latter have cis arrangement and ReN bond lengths of 186 pm. W hereas the thionitrosyl group is nearly linear, the R = N = SBr group has an ReNS angle of 165°.

Article

1998 ◽  
Vol 76 (3) ◽  
pp. 301-306
Author(s):  
Sengen Sun ◽  
James F Britten ◽  
Christopher N Cow ◽  
Chérif F Matta ◽  
Paul HM Harrison
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
The Other ◽  
Methyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Lengths ◽  
Form Part ◽  
Two Sides ◽  
Opposite Helicity

The crystal structure of 3,4,7,8-tetramethylglycoluril (5) was determined by X-ray diffraction. The structure reveals a hydrogen-bonding motif in the crystal lattice that differs from that present in related glycolurils. The two sides of each molecule form part of two independent, but parallel, infinite helical chains. These chains are formed by the NH donor and C==O acceptor on one side of a glycoluril molecule, forming H-bonds to two different molecules at adjacent positions within the helix. On the other side of the same molecule, a similar motif generates another helix of opposite helicity to the first. The molecule has a crystallographic plane of symmetry through the two bridgehead carbon atoms and the two bridgehead methyl groups, which are syn-periplanar. Thus, 5 is similar to 3,4-dimethylglycoluril (3), but differs from some glycolurils, where there is a significant dihedral angle between the two bridgehead-to-bridgehead substituent bonds. Bond lengths and angles in 5 resemble those reported for 3, but bond lengths around the bridgehead positions are slightly lengthened relative to 3.Key words: glycoluril, 1,2,5,8-tetramethyl-2,6,7,8-tetraazabicyclo[3.3.0]octane-3,7-dione, X-ray diffraction, crystal structure, hydrogen-bond array.

EXAFS and XRD investigations of zeunerite and meta-zeunerite

2003 ◽  
Vol 218 (1) ◽  
Author(s):  
C. Hennig ◽  
G. Reck ◽  
T. Reich ◽  
A. Roßberg ◽  
W. Kraus ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Lengths

AbstractIn this paper EXAFS was used to determine bond lengths in the structures of zeunerite and meta-zeunerite. The atomic distances between heavy and light scatterers observed using EXAFS in meta-zeunerite deviate approximately 0.1 Å from literature data of single-crystal X-ray diffraction measurements. Because this difference is significant higher than the error limits of EXAFS measurements, the complete crystal structure of meta-zeunerite, Cu[UO

Crystal structure of zerumbone [(E,E,E)-2,6,9,9-Tetramethylcycloundeca-2,6,10-trien-1-one]

1981 ◽  
Vol 34 (10) ◽  
pp. 2243 ◽  
Author(s):  
SR Hall ◽  
S Nimgirawath ◽  
CL Raston ◽  
A Sittatrakul ◽  
S Thadaniti ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Membered Ring ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Zingiber Zerumbet ◽  
Space Group ◽  
X Ray ◽  
Considerable Distortion

The crystal structure of zerumbone, C15H22O, extracted from the rhizomes of Zingiber zerumbet Smith, has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.051 for 925 'observed' reflections. Crystals are monoclinic, space group P21/c, a 9.036(3), b 9.712(5), c 15.643(6) �, β 97.19(3)�, Z = 4. Although the molecule has no chiral centre, the presence of the three trans double bonds confers considerable distortion and rigidity on the eleven-membered ring and renders the whole molecule chiral and potentially resolvable.

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