1H NMR Conformational Study of Viologen-Linked Porphyrins

1H-NMR stereospecific assignments by conformational data-base searches.

A search procedure is described for making stereospecific assignments at prochiral centers in proteins on the basis of nuclear Overhauser enhancement and coupling constant data derived from nmr experiments. A data base comprising torsion angles, associated 1H-1H coupling constants and interproton distances is searched by a computer algorithm for sets of values that match the experimental data w...

Conformational Study of some novel Methoxy Half-Analogues of Michler’s Ketone by NMR

One series of half-analogues of Michler’s ketone containing one or more terminal methoxysubstituents with variable tertiary amino groups have been used in this study. NMR spectralresults for the parent ketones confirm earlier findings that ortho proton shifts are apparentlyindependent from steric effects in derivatives of Michler’s ketone because the ring current andcarbonyl-induced shifts are ...

Rates of Acid-Catalyzed NH Proton Exchange of Enaminones, an 1H NMR Study

: 1H NMR spectra of a series of enaminones R-CO-CH=C(NHCH2Ph)-R  [1, R=CH3; 2, R=C6H5; 3, R=CF3; 4, R=CH2CH2CH2; 5, R=CH2C(CH3)2CH2], were obtained in the presence of trifluoroacetic acid in CDCl3 or DMSO-d6 at 28 °C. S...

Synthesis and Study of Photophysical Properties of a Few Viologen Linked Pyrenes

Conformational analysis of oligoarabinonucleotides. An NMR and CD study

A 500 and 300 MHz proton NMR study of the series of oligoarabinonucleotides 5'aAMP, 3'aAMP, aA-aA, (aA-)2aA and (aA-)3aA is presented. In addition, circular dichroism is used to study the stacking behaviour of aA-aA. The complete 1H-NMR spectral assignment of the compounds (except the tetramer) is given. Proton-proton and proton-phosphorus coupling constants, obtained by computer simulation of ...