Metal ion complexes of 1,4,7-triazacyclononane and their aminoalkyl derivatives. Analysis of chelate rings fusion and molecular mechanics study

1994 ◽  
Vol 72 (5) ◽  
pp. 1404-1411 ◽  
Author(s):  
Igor V. Pletnev
Keyword(s):  
Quantitative Analysis ◽  
Molecular Mechanics ◽  
Metal Ion ◽  
Chelate Ring ◽  
Critical Role ◽  
Molecular Mechanics Calculations ◽  
Metal Ion Complexes ◽  
X Ray ◽  
Coordination Bonds ◽  
Chelate Rings

Stereochemistry of metal ion complexes of 1,4,7-triazacyclononane, their N,N′,N′′-tris(aminoethyl), tris(aminopropyl), and their N,N′-(4,7-diazadecylene) derivatives is described in terms of the fusion of chelate rings at metal–nitrogen coordination bonds. Molecular mechanics calculations and analysis of the X-ray data confirm that the semi-quantitative analysis is valid and that fusion plays a critical role in the structure of the complexes. Molecular mechanics study of puckering of the ethylenediamine chelate ring, an essential part in this study, is also presented.

Molecular Mechanics Calculations and the Metal Ion Selective Extraction of Lanthanoids

1998 ◽  
Vol 37 (13) ◽  
pp. 3310-3315 ◽  
Author(s):  
Peter Comba ◽  
Karsten Gloe ◽  
Katsutoshi Inoue ◽  
Torsten Krüger ◽  
Holger Stephan ◽  
...  
Keyword(s):  
Molecular Mechanics ◽  
Metal Ion ◽  
Selective Extraction ◽  
Molecular Mechanics Calculations

The conformational preference and barrier to internal rotation of an equatorial 3,5-dichlorophenyl group by the J method. Derivatives of cyclohexane, 1,3-dithiane, 1,3-dioxane, and 1,3-dioxolane

1979 ◽  
Vol 57 (3) ◽  
pp. 355-359 ◽  
Author(s):  
Ted Schaefer ◽  
Walter Niemczura ◽  
Werner Danchura
Keyword(s):  
Magnetic Resonance ◽  
Molecular Mechanics ◽  
Internal Rotation ◽  
Phenyl Ring ◽  
Proton Magnetic Resonance ◽  
Conformational Preference ◽  
Molecular Mechanics Calculations ◽  
X Ray ◽  
Carbon Carbon Bond ◽  
Derivatives Of

We report the preparation and the analysis of the phenyl ring proton magnetic resonance spectra of 3,5-dichlorophenylcyclohexane and of the 2-(3,5-dichlorophenyl) derivatives of 1,3-dioxane, 1,3-dithiane, and 1,3-dioxolane. With the exception of the dioxolanes these compounds exist predominantly as the equatorial isomers. The J method is used to show that the phenyl moiety prefers the conformation in which the α C—H bond lies in the phenyl plane. The predominantly twofold barriers to rotation about the carbon–carbon bond between the two ring systems are 2.0 ± 0.3, 0.4 ± 0.2, 2.2 ± 0.3, 0.85 ± 0.3 kcal/mol for these compounds, in the order given above. The low value for the barrier in the 1,3-dioxane derivative agrees reasonably well with molecular mechanics calculations and with the results of calorimetric and X-ray studies on equatorial 2-phenyl-1,3-dioxane.

Conformational studies of muscarone analogs: x-ray analysis and molecular mechanics calculations

1992 ◽  
Vol 35 (2) ◽  
pp. 305-309 ◽  
Author(s):  
Patrick J. Carroll ◽  
Marco De Amici ◽  
Carlo De Micheli ◽  
Lucio Toma
Keyword(s):  
Molecular Mechanics ◽  
Molecular Mechanics Calculations ◽  
Conformational Studies ◽  
X Ray

Studies on the Nature and Strength of Pt . . .H(-N) Interactions. The Crystal Structures of Chloro[N-(2-aminoethyl)-N-(2-ammonioethyl)ethane-1,2-diamine]platinum(II) Chloride and Dichloro[4,7-diaza-1-azoniacyclononane]platinum(II) Tetrachlor

2000 ◽  
Vol 53 (6) ◽  
pp. 451 ◽  
Author(s):  
Murray S. Davies ◽  
Ronald R. Fenton ◽  
Fazlul Huq ◽  
Edwina C. H. Ling ◽  
Trevor W. Hambley
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Molecular Mechanics ◽  
Metal Ion ◽  
Monoclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Protonated Amine ◽  
Protonated Amines ◽  
Close Contacts

Two complexes, namely, chloro[N-(2-aminoethyl)-N-(2-ammonioethyl)ethane-1,2-diamine]platinum(II) chloride {[PtCl(tren+H)]Cl2} and dichloro[4,7-diaza-1-azoniacyclononane]platinum(II) tetrachloroplatinate(II)–water (1/2) {[PtCl2(tacn+H)]2[PtCl4]·2H2O}, have been prepared and structurally characterized by single-crystal X-ray diffractometry as part of a study of the nature and strength of Pt···H(–N) interactions. Crystals of [PtCl(tren+H)]Cl2 are monoclinic, space group P21/c, a 8.293(2), b 14.396(6), c 11.305(3) Å, β 107.34(2)º, Z 4, and the structure has been refined to a residual of 0.042 based on 1631 reflections. Crystals of [PtCl2(tacn+H)]2[PtCl4]·2H2O are monoclinic, space group P21/a, a 12.834(4), b 8.206(4), c 13.116(8) Å, β 93.01(4)˚, Z 2, and the structure has been refined to a residual of 0.035 based on 1974 reflections. In [PtCl(tren+H)]2+, the protonated amine forms hydrogen bonds with chloride anions and no close contacts with the metal ion. In [PtCl2(tacn+H)]+, a short intramolecular contact is observed between the metal and the protonated amine and the results of molecular mechanics modelling are consistent with there being a Pt···H hydrogen bond. Molecular mechanics modelling of [PtCl(tren+H)]2+ and [PtCl2(dien+H)]+ shows that the protonated amines could readily form close contacts with the metal. It is concluded that there is evidence for the formation of Pt···H(–N) hydrogen bonds but these bonds are very weak, being similar or lower in energy than Cl···H(–NPt) hydrogen bonds.

Preparation and characterization of Tl(1,2-C2H4Cl2)B(OTeF5)4: a metal complex of a least coordinating solvent and a least coordinating anion

1992 ◽  
Vol 70 (3) ◽  
pp. 726-731 ◽  
Author(s):  
Paul K. Hurlburt ◽  
Oren P. Anderson ◽  
Steven H. Strauss
Keyword(s):  
Metal Ion ◽  
Chelate Ring ◽  
Ion Solvation ◽  
Crystalline Compound ◽  
Triclinic Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Solid Salt ◽  
Solvent Metal

Addition of B(OTeF5)3 to TIOTeF5 in the weakly coordinating solvents dichloromethane, 1,2-dichloroethane, and 1,1,2-trichlorotrifluoroethane produces solutions of M(solv)x+B(OTeF5)4−. When the solvent was 1,2-dichloroethane, the crystalline compound Tl(1,2-C2H4Cl2)B(OTeF5)4 was isolated and studied by X-ray crystallography: triclinic, space group [Formula: see text], a = 9.221 (4), b = 11.396(5), c = 12.538 (4) Å, α = 110.75 (3)°, β = 101.72(3)°, γ = 99.74 (3)°, Z = 2, T = −116 °C. The Tl(1,2-C2H4Cl2)+ cation contains a five-membered chelate ring with Tl—Cl distances of 3.138 (4) and 3.179 (3) Å. The metal ion is weakly bonded to four B(OTeF5)4− counterions, with nine Tl—F interactions that range from 2.950 (5) to 3.981 (8) Å. When the solvent is dichloromethane or 1,1,2-trichlorotrifluoroethane, only the unsolvated solid salt TlB(OTeF5)4 can be isolated by crystallization. This salt is thermally unstable, slowly forming TlOTeF5 and volatile B(OTeF5)3. Keywords: noncoordinating anion, noncoordinating solvent, metal ion solvation.

Hexa Schiff-base cryptands: solution thermodynamic and X-ray crystallographic studies of main group, transition and heavy metal ion complexes

1996 ◽  
pp. 2747-2755 ◽  
Author(s):  
Rym Abidi ◽  
Françoise Arnaud-Neu ◽  
Michael G. B. Drew ◽  
Sarah Lahély ◽  
Debbie Marrs ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Schiff Base ◽  
Metal Ion ◽  
Main Group ◽  
Heavy Metal Ion ◽  
Metal Ion Complexes ◽  
X Ray
Sign in / Sign up

Export Citation Format

Share Document