Tungsten-183 chemical shifts in cis- and trans-bis(tributylphosphine)tetracarbonyltungsten

1971 ◽  
Vol 10 (1) ◽  
pp. 206-207 ◽  
Author(s):  
Paul Joseph Green ◽  
Thomas Henderson Brown
Keyword(s):  
Chemical Shifts ◽  
Cis And Trans ◽  
In Cis

Orientation of the methoxyl group in cis- and trans-2-methoxy-4-methyl-1,3-dioxanes and related compounds as inferred by 1H and 13C nmr spectroscopy. The significance of the "exo-anomeric" effect

1982 ◽  
Vol 60 (9) ◽  
pp. 1067-1072 ◽  
Author(s):  
Vanga S. Rao
Keyword(s):  
Dynamic Equilibrium ◽  
Chemical Shifts ◽  
13C Nmr Spectroscopy ◽  
Methoxyl Group ◽  
Anomeric Effect ◽  
1H And 13C Nmr ◽  
Nuclear Overhauser ◽  
Cis And Trans ◽  
In Cis ◽  
Related Compounds

Carbon-13 chemical shifts and 13C—1H couplings are reported for some substituted 2-methoxy-1,3-dioxanes and related tetrahydropyran derivatives. These data, together with nuclear Overhauser enhancement experiments, provided evidence for a favored orientation of the methoxyl group. From an analysis of the 13C chemical shifts and the magnitude of vicinal 13C—1H coupling between —OCH3 and H-2, a possible dynamic-equilibrium orientation for the methoxyl group is proposed, and an evaluation of the significance of a "generalized exo-anomeric effect" is presented.

Cis–Trans Conformational Dependence of the Carboxylate pK in Glycylsarcosine

1974 ◽  
Vol 52 (12) ◽  
pp. 2348-2352 ◽  
Author(s):  
R. A. Morton ◽  
S. S. Danyluk
Keyword(s):  
Chemical Shift ◽  
Theoretical Calculations ◽  
Chemical Shifts ◽  
Molecular Models ◽  
Amino Groups ◽  
Cis And Trans ◽  
In Cis ◽  
Cis Isomer

A study is reported of the influence of pD upon the 220 MHz proton n.m.r. spectrum of the dipeptide glycylsarcosine (Gly-Sar) in D2O at 23 °C. Variation of pD produces characteristic changes in chemical shifts for Gly-Sar and an analysis of the pD–chemical shift curves shows that the carboxyl pK differs significantly in cis and trans conformers, having values of 3.01 ± 0.03 and 3.39 ± 0.03, respectively. From a consideration of molecular models and theoretical calculations, it is concluded that the pK difference arises from a closer juxtaposition of terminal carboxyl and amino groups in the cis isomer.

Solvent, concentration, and temperature dependance of the platinum–phosphorus nuclear magnetic résonance coupling constants in cis- and trans-[PtCl2(PBu3n)2]

1976 ◽  
Vol 54 (17) ◽  
pp. 2733-2738 ◽  
Author(s):  
Keith R. Dixon ◽  
Martin Fakley ◽  
Alan Pidcock
Keyword(s):  
Chemical Shifts ◽  
Specific Model ◽  
Coupling Constants ◽  
Solvent Concentration ◽  
Reaction Field ◽  
Magnetic Resonance Coupling ◽  
Resonance Coupling ◽  
Temperature Dependance ◽  
Cis And Trans ◽  
In Cis

Studies of the effects of solvent, concentration and temperature on the 31P nmr parameters of cis- and trans-[PtCl2(PBun3)2] are reported. The coupling constants, 1JPt–P are markedly dependent upon all three variables but, in contrast to previous studies on non-coordination compounds, very little corresponding variation in chemical shifts is found. Results are discussed in terms of a solvent cavity model using reaction field, Stark and Macrae effects but it is concluded that a more specific model involving competitive solvation at platinum gives a better interpretation of the data.

Long-range deuterium-induced isotope effects on 1H chemical shifts in cis- and trans-stilbene

1997 ◽  
Vol 410-411 ◽  
pp. 9-12
Author(s):  
P. Novak ◽  
Z. Meić ◽  
D. Vikić-Topić ◽  
H. Sterk
Keyword(s):  
Long Range ◽  
Chemical Shifts ◽  
Isotope Effects ◽  
Trans Stilbene ◽  
Cis And Trans ◽  
In Cis

scholarly journals Hydrogen Peroxide Oxidation of Coordinated Thiocyanate Ion in cis- and trans-[Coen2NH3NCS]2+: The Preparation and Properties of trans-[Coen2NH3CN]2+

1973 ◽  
Vol 51 (24) ◽  
pp. 4152-4158 ◽  
Author(s):  
Albert Richard Norris ◽  
James William Lennox Wilson
Keyword(s):  
Hydrogen Peroxide ◽  
Spectral Properties ◽  
Peroxide Oxidation ◽  
Reaction Conditions ◽  
Thiocyanate Ion ◽  
Hydrogen Peroxide Oxidation ◽  
Percent Conversion ◽  
Cis And Trans ◽  
In Cis

The hydrogen peroxide oxidation of thiocyanate ion in cis- and trans-[Coen2NH3NCS]2+ leads to the formation of the corresponding cis- and trans-cyanoammine- and diamminebis(ethylenediamine)cobalt-(III) complexes. The spectral properties of the previously unreported trans-[Coe2NH3CN]2+ are reported and compared to the spectral properties of the cis-isomer.Observations are made concerning the reaction conditions which favor a high percent conversion of trans-[Coen2NH3NCS]2+ to trans-[Coen2NH3CN]2+.

Structure and chemical bonding in cis- and trans-M(NO)2(O2CR)2 (M=Cr and Mo) complexes

Polyhedron ◽  
2000 ◽  
Vol 19 (26-27) ◽  
pp. 2565-2572 ◽  
Author(s):  
Ludmiła Szterenberg ◽  
Szczepan Roszak ◽  
Renata Matusiak ◽  
Antoni Keller
Keyword(s):  
Chemical Bonding ◽  
Cis And Trans ◽  
In Cis
Sign in / Sign up

Export Citation Format

Share Document