Notizen: The Preparation and Structure of Lithium (R, S)-Ethylenediamine-N,N′-disuccinatocobaltate(III) Trihydrate

1977 ◽  
Vol 32 (9) ◽  
pp. 1089-1090 ◽  
Author(s):  
F. Pavelcík ◽  
J. Majer
Keyword(s):  
Chelate Ring ◽  
Space Group ◽  
X Ray ◽  
Envelope Conformation

Crystals of LiCo[(R,S)-EDDS] • 3 H2O have been synthetized and its structure was determined by X-ray analysis. Monoclinic, α = 9.624, b = 12.788, c = 12.049 Å, β = 94.85°, space group P21/c. The crystal consists of binuclear units Co2[(R,S)-EDDS]22-. The central ethylenediamine chelate ring has an envelope conformation.

Synthesis and structural characterization of donor-stabilized disubstituted diphenyldithiophosphates of nickel(II)

2014 ◽  
Vol 70 (4) ◽  
pp. 761-767 ◽  
Author(s):  
Sandeep Kumar ◽  
Ruchi Khajuria ◽  
Amanpreet Kaur Jassal ◽  
Geeta Hundal ◽  
Maninder S. Hundal ◽  
...  
Keyword(s):  
Single Crystal ◽  
Chelate Ring ◽  
Donor Ligands ◽  
Monoclinic Space Group ◽  
Bidentate Ligands ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray

Donor-stabilized addition complexes of nickel(II) with disubstituted diphenyldithiophosphates, [{(ArO)2PS2}2NiL2] {Ar = 2,4-(CH3)2C6H3[(1), (5)], 2,5-(CH3)2C6H3[(2), (6)], 3,4-(CH3)2C6H3[(3), (7)] and 3,5-(CH3)2C6H3[(4), (8)];L= C5H5N [(1)–(4)] and C7H9N [(5)–(8)]}, were successfully isolated and characterized by elemental analysis, magnetic moment, IR spectroscopy and single-crystal X-ray analysis. Compound (4) crystallizes in the monoclinic space groupP21/nwhereas compounds (7) and (8) crystallize in the triclinic space group P\bar 1. The single-crystal X-ray diffraction analysis of (4), (7) and (8) reveals a six-coordinated octahedral geometry for the NiS4N2chromophore. Two diphenyldithiophosphate ions act as bidentate ligands with their S atoms coordinated to the Ni centre. Each of them forms a four-membered chelate ring in the equatorial plane. The N atoms from two donor ligands are axially coordinated to the Ni atom.

Structure and conformation of 5-methoxymethyl-1-(2′-deoxy-β-D-lyxofuranosyl)uracil

1986 ◽  
Vol 64 (7) ◽  
pp. 1305-1309 ◽  
Author(s):  
J. Wilson Quail ◽  
Irena Ekiel ◽  
Ossama A. L. El-Kabbani ◽  
Guy Tourigny ◽  
Louis T. J. Delbaere ◽  
...  
Keyword(s):  
Crystallographic Analysis ◽  
Side Chain ◽  
Nmr Analysis ◽  
Space Group ◽  
X Ray ◽  
Envelope Conformation ◽  
Sugar Ring ◽  
Glycosidic Conformation

The structure of the nucleoside 5-methoxymethyl-1-(2′-deoxy-β-D-lyxofuranosyl)uracil (MMdLU) was deduced by X-ray crystallographic analysis. MMdLU crystallized in space group P21 with a = 8.719(4), b = 13.188(3), c = 5.701(3) Å, β = 109.56(2)° and Z = 2; R = 0.040 for 1208 unique reflections with net I > 2σ(I). The furanose ring adopts the rare C(4′)—exo envelope conformation (4E). The glycosyl linkage is anti (χ = 243.5°) and the C(5′) side chain has the t conformation. The conformation was also determined in solution by nmr analysis. The sugar ring exists in the N-conformation (97 ± 5%), the populations of the three rotamers about the exocyclic C(4′)—C(5′) bond were estimated to be g+:t:g− = 23%:59%:18% and the glycosidic conformation is predominantly anti.

X-Ray Structural Study of Terguride SolvatesTerguride Methanol Solvate

1994 ◽  
Vol 59 (1) ◽  
pp. 149-158 ◽  
Author(s):  
Bohumil Kratochvíl ◽  
Jiří Novotný ◽  
Michal Hušák ◽  
Jiří Had ◽  
Josef Stuchlík ◽  
...  
Keyword(s):  
Diffraction Study ◽  
Structural Study ◽  
Powder Diffraction ◽  
Direct Methods ◽  
Lattice Parameters ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Envelope Conformation

The structure of the unstable solvate of the semisynthetic ergot derivate terguride methanol solvate C20H28N4O .CH3OH, was solved by direct methods and refined to an R value of 0.093 for 1 462 unique observed reflections. The title alkaloid crystallizes in the orthorhombic space group P212121 with lattice parameters a = 10.438(1), b = 13.200(4), c = 15.495(5) Å, V = 2 134.8(9) Å3, Z = 4. An indole moiety of the terguride molecule is almost perfect planar, ring C has an E6 envelope conformation and ring D adopts a 1C4 chair shape. As found from X-ray powder diffraction study, terguride methanol solvate completely transforms to terguride monohydrate in air during several hours.

Conformational analysis of coordination compounds. XIII. Complexes of 2-methylpentane-2,4-diamine

1981 ◽  
Vol 34 (12) ◽  
pp. 2525 ◽  
Author(s):  
TW Hambley ◽  
CJ Hawkins ◽  
JA Palmer ◽  
MR Snow
Keyword(s):  
Chelate Ring ◽  
Cobalt Complex ◽  
Platinum Complex ◽  
Chair Conformation ◽  
Geometrical Parameters ◽  
Boat Conformation ◽  
Space Group ◽  
X Ray ◽  
Strain Energy Minimization ◽  
Good Agreement

The crystal structures of tetraammine{(�)-2-methylpentane-2,4-diamine} cobalt(III) tetrachlorozincate chloride and 2,2'-bipyridine{(�)-2-methylpentane-2,4-diamine)platinum(II) nitrate semihydrate have been determined by X-ray structure analysis. The former crystals are orthorhombic with the space group P212121, with a 12.49, b 20.16 and c 7.68 �. The latter crystals are also orthorhombic but with the space group Pbca with a 14.96, b 28.69 and c 19.45 �. Both structures have been refined by least-squares methods to weighted R values of 0.034 (1407 reflections) and 0.055 (2301 reflections), respectively. The six-membered diamine chelate ring has a flattened chair conformation in the cobalt complex, and an unsymmetric boat conformation in the platinum complex. Strain-energy-minimization calculations show these structures correspond to energy minima and the calculated geometrical parameters are in good agreement with those observed for the chelate ring. Proton n.m.r. spectra are consistent with the chair conformation being almost exclusively populated in the ammine complex and in the tetracyanocobaltate(III) complex in aqueous solution, but the and 13C n.m.r. spectra of the platinum(II) complex show that, although the chair conformer predominates, the boat conformation is significantly populated in solution.

Structural studies of organoboron compounds LXIII. Reaction of ketoximes with aldehydes and diphenylborinic acid, and the crystal and molecular structures of two different types of boron chelates and one of the precursor aldehyde adducts

1995 ◽  
Vol 73 (6) ◽  
pp. 835-845 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Ulf Riebe ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Chelate Ring ◽  
Direct Methods ◽  
Crystallographic Analysis ◽  
Molecular Structures ◽  
Boron Compounds ◽  
One Pot ◽  
Boron Chelates ◽  
Space Group ◽  
X Ray ◽  
Diphenylboron Chelates

The diphenylboron chelates of ketoxime adducts to formaldehyde and trichloroacetaldehyde (chloral) have been synthesized. The reactions were carried out as three-component one-pot reactions, and also as two-step reactions for the ketoxime chloral adducts, which were isolated and characterized before reaction with oxybis(diphenylborane) to form the diphenylboron chelates. One of the intermediate adducts and two of the diphenylboron chelates have been characterized by X-ray crystallographic analysis. Crystals of O-(2,2,2-trichloro-1-hydroxyethyl)-2-propanonoxime, 8d, are monoclinic, a = 7.010(2), b = 11.832(3), c = 11.684(2) Å, β = 90.48(2)°, Z = 4, space group P21/c; those of 4-isopropylidene-2,2-diphenyl-1,3-dioxa-4-azonia-2-boratacyclopentane, 9a, are orthorhombic, a = 11.098(2), b = 15.364(1), c = 8.715(2) Å, Z = 4, space group P212121; and those of 5-trichloromethyl-2-isopropylidene-3,3-diphenyl-1,4-dioxa-2-azonia-3-boratacyclopentane, 10d, are monoclinic, a = 9.164(2), b = 15.304(3), c = 13.859(2) Å, β = 105.28(1)°, Z = 4, space group P21/n. The structures were solved by direct methods and refined by full-matrix least-squares procedures to R = 0.037, 0.044, and 0.040 (Rw = 0.041, 0.016, and 0.042) for 1082, 1256, and 3062 reflections with I ≥ 3σ(F2), respectively. The X-ray analyses show that the products from the reaction between acetonoxime, oxybis(diphenylborane), and formaldehyde or trichloroacetaldehyde, respectively, possess different boron chelate structures. With formaldehyde a COBON chelate ring is obtained and with trichloroacetaldehyde a BOCON chelate ring is formed. Keywords: boron chelates, boron compounds, organboron compounds, crystal structures.

Crystal structure of an inclusion complex between chiral monoaza-15-crown-5 and S(–)-1-phenyl-ethyl ammonium percholorate

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören
Keyword(s):  
Crystal Structure ◽  
Inclusion Complex ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Type

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group

The empirical conformational surface of the co(ethylenediamine) ring

1990 ◽  
Vol 55 (6) ◽  
pp. 1427-1434 ◽  
Author(s):  
František Pavelčík ◽  
Eva Luptáková
Keyword(s):  
Potential Surface ◽  
Chelate Ring ◽  
Statistical Treatment ◽  
Mirror Image ◽  
Fold Axis ◽  
Empirical Potential ◽  
Reduction Of Dimensionality ◽  
Envelope Conformation ◽  
Structural Correlation ◽  
Structural Database

The conformational surface of the Co(en) chelate ring was studied by the method of structural correlation. The reduction of dimensionality of the conformation problem was achieved by employing the pseudorotation concept. The empirical potential surface was obtained by statistical treatment of 743 independent conformations from the Cambridge Structural Database. The theoretical potential surface was obtained by molecular mechanics. The minimal-energy conformation is gauche with the Co atom on the two-fold axis. Conformational flexibility also includes an envelope conformation with the N atom bent out of the plane. The transition between the mirror-image symmetrical conformations can occur by a pseudorotation pathway and is accompanied by increased planarity of the ring. The transition state is an envelope conformation with an out-plane Co atom.

Sterically Crowded Heterocycles. VI. Relative Configuration of Diastereoisomeric (Z)-1,3-Diphenyl-3-(5-methyl-2-phenylimidazo[1,2-a]pyridin-3-yl)prop-2-en-1-ols

1996 ◽  
Vol 61 (9) ◽  
pp. 1380-1385 ◽  
Author(s):  
Jan Čejka ◽  
Richard Kubík ◽  
Bohumil Kratochvíl ◽  
Josef Kuthan
Keyword(s):  
Preparative Separation ◽  
Orthorhombic Space Group ◽  
Relative Configuration ◽  
Space Group ◽  
X Ray

Relative configuration of the titled racemic compounds 1a and 1b has been elucidated on the basis of a complete X-ray structure determined for the higher melting diastereoisomer. The compound 1a crystallizes in the orthorhombic space group P21212, a = 15.610(3) Å, b = 18.634(4) Å, c = 7.5672(7) Å, V = 2201.1(6) Å3, Z = 4. Preparative separation of both diastereoisomers is reported.

scholarly journals Molekül- und Kristallstruktur von 1.1-Dimethylsilylentitanocendichlorid, (CH3)2Si(C5H4)2TiCl2 / Molecular and Crystal Structure of l,r-Dimethylsilylene Titanocene Dichloride, (CH3)2Si(C5H4)2TiCl2

1981 ◽  
Vol 36 (10) ◽  
pp. 1208-1210 ◽  
Author(s):  
Hartmut Köpf ◽  
Joachim Pickardt
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Structure Determination ◽  
Titanocene Dichloride ◽  
Molecular And Crystal Structure ◽  
Monoclinic Space Group ◽  
Crystal Data ◽  
Space Group ◽  
X Ray ◽  
Structural Dimensions

Abstract The molecular structure of the bridged [1]-titanocenophane 1,1'-dimethylsilylene titanocene dichloride, (CH3)2Si(C5H4)2TiCl2, has been investigated by an X-ray structure determination. Crystal data: monoclinic, space group C2/c, Z = 4, a = 1332.9(3), 6 = 988.7(3), c = 1068.9(3) pm, β = 113.43(2)°. The results are compared with the structural dimensions of similar compounds: 1,1'-methylene titanocene dichloride, CH2(C5H4)TiCl2, with the unbridged titanocene dichloride, (C5H5)2TiCl2 and the ethylene-bridged compound (CH2)2(C5H4)2TiCl2

Supramoleküle aus Kronenethern und geminalen Sulfonen: Synthese von vier binären Komplexen und Kristallstruktur von (CH2CH2O)4·2H 2C(SO2C2H5)2/Supramolecules of Crown Ethers with Geminal Sulfones: Synthesis of Four Binary Complexes and Crystal Structure of (CH2CH2O )4·2H2C(SO2C2H5)2

1995 ◽  
Vol 50 (7) ◽  
pp. 1018-1024 ◽  
Author(s):  
Axel Michalides ◽  
Dagmar Henschel ◽  
Armand Blaschette ◽  
Peter G. Jones
Keyword(s):  
Monoclinic Space Group ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Binary Complexes ◽  
Cyclic Polyethers ◽  
Adjacent Unit ◽  
Methylene Group

In a systematic search for supramolecular complexes involving all combinations of the cyclic polyethers 12-crown-4 (12C4), 15-crown-5 (15C 5), 18-crown-6 (18C 6) and dibenzo- 18-crown-6 (DB -18C6), and the geminal di- or trisulfones H2C(SO 2Me)2, H2C (SO2Et)2 and HC (SO2Me)3-n (SO2Et)n (n = 0 -3 ) , only the following four complexes could be isolated and unequivocally characterized by elemental analysis and 1H NMR spectroscopy: [(12C4){H2C (SO2Et)2}2] (3), [(18C6){H2C (S O2Me)2}] (4), [(DB -18C 6){H2C (SO2Et)2}] (5) and [(D B -18C 6)2{HC (SO2Me )(SO2Et)2}3] (6). The structure of 3 (triclinic, space group P1̄) consists of crystallographically centrosymmetric formula units, in which the disulfone molecules are bonded on each side of the ring by two C -H ··· O(crown) interactions originating from the central methylene group (H···O 213 pm) and from the methylene group of one EtSO2 moiety ( H ··· O 237 pm). Formula units related by translation are connected into parallel strands by a third type of reciprocal C -H ···O bond (H ···O 232 pm) between the second H atom of the central methylene group and a sulfonyl oxygen atom of the adjacent unit. The structure of 4 (monoclinic, space group C2/c) showed severe disorder of the crown ether and could not be refined satisfactorily. Compounds 5 and 6 crystallized as long and extremely thin fibres, indicative of linear-polymeric supramolecular structures; single crystals for X-ray crystallography were not available.

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