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.

The High Resolution NMR Spectra of Pesticides. I. Organophosphorus Pesticides

1968 ◽  
Vol 51 (5) ◽  
pp. 1063-1094 ◽  
Author(s):  
Lawrence H Keith ◽  
Arthur W Garrison ◽  
Ann L Alford
Keyword(s):  
Chemical Shifts ◽  
Organophosphorus Pesticides ◽  
Coupling Constants ◽  
Reference Source ◽  
Cis And Trans Isomers ◽  
Nuclear Magnetic Resonance Spectra ◽  
Trifluoracetic Acid ◽  
Methylene Groups ◽  
Dilution Effects ◽  
Cis And Trans

Abstract A description of the 100 MHz nuclear magnetic resonance spectra of forty organophosphorus pesticides is presented as an identification aid and reference source. Chemical shifts and coupling constants are presented in tabular form, along with a discussion and figures of the more complex or unusual spectra. Tables of trends in chemical shifts and coupling constants as related to structure are included. Homonuclear spin decoupling, integration, protonation with trifluoracetic acid, D20 exchange, temperature, solvent and dilution effects, and supplemental 60 MHz spectra all were employed in correlating the spectra with the structures of the corresponding molecules. Interesting phenomena observed include long-range phosphorus to hydrogen coupling through four and five bonds, chemical nonequivalence of methylene groups and methyl groups in (CH3CH20)2P and (CH30)2P moieties, differences in the spectra of the cis and trans isomers of two pesticides due to anisotropic effects of their carbonyl groups, and magnetic nonequivalence of geminal methylene protons adjacent to an asymmetric carbon atom

Carbon-13 and nitrogen-15 NMR spectra of cis- and trans-azobenzene, 4-monosubstituted and 4,4'-disubstituted trans-azobenzenes

1982 ◽  
Vol 47 (4) ◽  
pp. 1112-1120 ◽  
Author(s):  
Antonín Lyčka
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Downfield Shift ◽  
Signal Assignment ◽  
In Series ◽  
Characteristic Values ◽  
The Individual ◽  
Cis And Trans ◽  
Trans Azobenzene

13C and 15N NMR spectra of cis- and trans-azobenzene, 4-substituted trans-azobenzenes (N(CH3)2; NH2; OH; OCH3; CH3; Br; NO2) and 4,4'-disubstituted trans-azobenzenes (OH; NO2; NH2; OH; N(CH3)2, CH3; N(CH3)2, NO2) were measured. In comparison with trans-azobenzene, cis-azobenzene exhibits a downfield shift of nitrogen and C(1) signals and an upfield one of the C(2) and C(4) signals. The individual coupling constants nJ(15N13C) in 4-substituted and 4,4'-disubstituted trans-azobenzenes, respectively, have characteristic values and can be used for carbon signal assignment. With 4-substituted trans-azobenzenes, the 15N substitution chemical shifts of the nitrogen of the azo-bond were determined and their additivity in series of 4,4'-disubstituted trans-azobenzenes was proved.

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