The empirical conformational surface of the co(ethylenediamine) ring

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.

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Bis(3-ethoxy-4-hydroxybenzaldehyde thiosemicarbazonato-κ2 S,N)nickel(II) monohydrate

Acta Crystallographica Section E Structure Reports Online ◽

10.1107/s1600536806008348 ◽

2006 ◽

Vol 62 (4) ◽

pp. m799-m800

Author(s):

Li-Fang Jiang ◽

Zun-Xing Huang ◽

Jia-Hong Chen

Keyword(s):

Crystal Structure ◽

Water Molecule ◽

Title Compound ◽

Chelate Ring ◽

Planar Geometry ◽

Inversion Center ◽

Envelope Conformation ◽

Membered Chelate Ring ◽

Uncoordinated Water Molecule ◽

Square Planar

In the crystal structure of the title compound, [Ni(C10H12N3O2S)2]·H2O, the NiII atom is located on an inversion center and is chelated by two hydroxyethoxybenzaldehyde thiosemicarbazonate anions in a square-planar geometry. The five-membered chelate ring assumes an envelope conformation, with the Ni atom lying at the flap position. The uncoordinated water molecule is disordered over another inversion center and is hydrogen bonded to the NiII complex.

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[1,2-Bis(dicyclohexylphosphanyl)-1,2-dicarba-closo-dodecaborane-2κ2P,P′]di-μ-chlorido-1:2κ4Cl:Cl-dichlorido-1κ2Cl-dimercury(II)

Acta Crystallographica Section E Structure Reports Online ◽

10.1107/s1600536814006096 ◽

2014 ◽

Vol 70 (4) ◽

pp. m140-m140

Author(s):

Liguo Yang

Keyword(s):

Metal Atom ◽

Title Compound ◽

Chelate Ring ◽

The Other ◽

Coordination Geometry ◽

Tetrahedral Coordination ◽

Axis Direction ◽

Envelope Conformation ◽

The Mean ◽

Distorted Tetrahedral Coordination

The title compound, [Hg2Cl4(C26H54B10P2)], was synthesized by the reaction of 1,2-bis(dicyclohexylphosphanyl)-1,2-dicarba-closo-dodecaborane with HgCl2. Both HgIIatoms show a distorted tetrahedral coordination geometry, provided by the two bridging chloride anions and the P atoms of the diphosphanyl ligand for one metal atom, and by two bridging and two terminal chloride anions for the other. The five-membered HgP2C2chelate ring assumes an envelope conformation, with the HgIIatom displaced by 0.1650 (5) Å from the mean plane of the other four atoms (r.m.s. deviation = 0.002 Å). In the crystal, B—H...Cl interactions link the molecules, forming a supramolecular chain along thea-axis direction.

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On the preferences of five-membered chelate rings in coordination chemistry: insights from the Cambridge Structural Database and theoretical calculations

Dalton Transactions ◽

10.1039/c9dt00542k ◽

2019 ◽

Vol 48 (17) ◽

pp. 5476-5490 ◽

Cited By ~ 10

Author(s):

Maryam Bazargan ◽

Masoud Mirzaei ◽

Antonio Franconetti ◽

Antonio Frontera

Keyword(s):

Coordination Chemistry ◽

Metal Ions ◽

Chelate Ring ◽

Theoretical Calculations ◽

Cambridge Structural Database ◽

Membered Chelate Ring ◽

Structural Database ◽

Theoretical Results ◽

Chelate Rings

We illustrate, combining experimental and theoretical results, that the five-membered chelate ring is able to adapt itself to a great variety of metal ions.

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

Zeitschrift für Naturforschung B ◽

10.1515/znb-1977-0924 ◽

1977 ◽

Vol 32 (9) ◽

pp. 1089-1090 ◽

Cited By ~ 3

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.

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Spectroscopic properties and potential-energy surfaces for T-shaped van der Waals complexes. Part 2.—The empirical potential surface for ArCO2

Journal of the Chemical Society Faraday Transactions 2 Molecular and Chemical Physics ◽

10.1039/f29878300191 ◽

1987 ◽

Vol 83 (1) ◽

pp. 191-209 ◽

Cited By ~ 28

Author(s):

Adrian M. Hough ◽

Brian J. Howard

Keyword(s):

Potential Energy ◽

Potential Energy Surfaces ◽

Potential Surface ◽

Van Der Waals ◽

Spectroscopic Properties ◽

Van Der Waals Complexes ◽

Empirical Potential ◽

Energy Surfaces

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Friedel'S law breakdown and interpretation of stacking fault images in tetrahedral semiconductors

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100126408 ◽

1987 ◽

Vol 45 ◽

pp. 318-319

Author(s):

Rob. W. Glaisher ◽

A.E.C. Spargo

Keyword(s):

Relative Phase ◽

Point Group ◽

Binary Compound ◽

Stacking Fault ◽

Fold Axis ◽

Atom Pair ◽

Tetrahedral Semiconductors ◽

Group Symmetries ◽

Thin Crystal ◽

Phase Differences

Images of <11> oriented crystals with diamond structure (i.e. C,Si,Ge) are dominated by white spot contrast which, depending on thickness and defocus, can correspond to either atom-pair columns or tunnel sites. Olsen and Spence have demonstrated a method for identifying the correspondence which involves the assumed structure of a stacking fault and the preservation of point-group symmetries by correctly aligned and stigmated images. For an intrinsic stacking fault, a two-fold axis lies on a row of atoms (not tunnels) and the contrast (black/white) of the atoms is that of the {111} fringe containing the two-fold axis. The breakdown of Friedel's law renders this technique unsuitable for the related, but non-centrosymmetric binary compound sphalerite materials (e.g. GaAs, InP, CdTe). Under dynamical scattering conditions, Bijvoet related reflections (e.g. (111)/(111)) rapidly acquire relative phase differences deviating markedly from thin-crystal (kinematic) values, which alter the apparent location of the symmetry elements needed to identify the defect.

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