A detailed NMR study of the solution stereodynamics in tricarbonylrhenium(I) halide complexes of the non-racemic chiral ligand 2,6-bis[(4R,5R)-dimethyl-1,3-dioxan-2-yl]pyridine (L1) and the molecular structure of fac-[ReBr(CO)3(L1)] †

1999 ◽  
pp. 4495-4501 ◽  
Author(s):  
Peter J. Heard ◽  
Paul M. King ◽  
Alex. D. Bain ◽  
Paul Hazendonk ◽  
Derek A. Tocher
Keyword(s):  
Molecular Structure ◽  
Chiral Ligand ◽  
Nmr Study ◽  
Halide Complexes

scholarly journals Stereochemical rearrangements in tricarbonylrhenium(I) halide complexes of the nonracemic chiral ligand 2-[(4R,5R)-dimethyl-1,3-dioxan-2-yl]pyridine (L): a dynamic NMR study

1999 ◽  
Vol 77 (11) ◽  
pp. 1707-1715 ◽  
Author(s):  
Peter J Heard ◽  
Alex D Bain ◽  
Paul Hazendonk
Keyword(s):  
Carbon Atom ◽  
Chiral Ligand ◽  
Dynamic Nmr ◽  
Free Energies ◽  
Ligand Dissociation ◽  
Nmr Study ◽  
Nmr Techniques ◽  
Halide Complexes ◽  
Acetal Ring ◽  
Acetal Carbon

Tricarbonylrhenium(I) halide complexes of the nonracemic chiral ligand 2-[(4R,5R)-dimethyl-1,3-dioxan-2-yl]pyridine (L), namely fac-[ReX(CO)3L] (X = Cl, Br, or I), have been prepared and their latent fluxionality studied by dynamic NMR techniques in the slow and intermediate exchange regimes. In solution, these complexes give rise to four diastereoisomers, depending on the configuration at the metal and at the acetal-carbon atom, respectively; the relative populations are in the order SR > RR >>; RS > SS. At moderate temperatures, a reversible "acetal ring flip" leads to formal inversion of configuration at the acetal-carbon atom; the free energies of activation are in the range 84-88 kJ mol-1 at 298 K. Above ca. 370 K, reversible ligand dissociation also occurs, leading to an exchange of all four diastereoisomers on the NMR chemical shift time-scale.Key words: dynamic NMR, fluxionality, tricarbonylrhenium(I) complexes, chiral acetal ligands.

Combined X-ray Diffraction and15N CPMAS NMR Study of Molecular Structure and Proton Order/Disorder Phenomena in CyclicN,N‘-Bisarylformamidine Dimers

1997 ◽  
Vol 119 (50) ◽  
pp. 12223-12230 ◽  
Author(s):  
Romana Anulewicz ◽  
Iwona Wawer ◽  
Tadeusz Marek Krygowski ◽  
Ferdinand Männle ◽  
Hans-Heinrich Limbach
Keyword(s):  
Molecular Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nmr Study

scholarly journals 1H NMR study of the effect of variable ligand on heme oxygenase electronic and molecular structure

2009 ◽  
Vol 103 (1) ◽  
pp. 10-19 ◽  
Author(s):  
L MA ◽  
Y LIU ◽  
X ZHANG ◽  
T YOSHIDA ◽  
G LAMAR
Keyword(s):  
Molecular Structure ◽  
1H Nmr ◽  
Heme Oxygenase ◽  
Nmr Study

NMR study of antipyrine adducts with lanthanide shift reagents. Molecular structure of 2,3-dimethyl -1-phenyl- 5-ethoxypyrazole

1989 ◽  
Vol 25 (2) ◽  
pp. 152-157
Author(s):  
E. I. Oblapenko ◽  
A. V. Polyakov ◽  
A. I. Ermakov ◽  
A. I. Yanovskii ◽  
A. V. Krylov ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Nmr Study ◽  
Lanthanide Shift Reagents ◽  
Shift Reagents

scholarly journals A multinuclear NMR study of some cyclic phosphonic diamides

1994 ◽  
Vol 12 (1) ◽  
pp. 31-34
Author(s):  
Wojciech Bocian ◽  
Lech Stefaniak ◽  
Graham A. Webb
Keyword(s):  
Molecular Structure ◽  
Chemical Shifts ◽  
Multinuclear Nmr ◽  
Nmr Data ◽  
Nmr Study ◽  
Sensitive Parameters

1H,13C,15N and31p NMR data are presented for four cyclic phosphonic diamides. In tenns of useful structural infonnation it is found that the31p chemical shifts and1J(31P_15N) couplings are the most sensitive parameters to variations in molecular structure.

Cyclic Aluminophosphinate: Molecular Structure, and Solid-State Multinuclear NMR Study

2001 ◽  
Vol 169 (1) ◽  
pp. 277-280
Author(s):  
Thierry Azais ◽  
Christian Bonhomme ◽  
Laure Bonhomme-Coury ◽  
Jacqueline Vaissermann ◽  
Philippe Bertani ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Solid State ◽  
Multinuclear Nmr ◽  
Nmr Study
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