13C nuclear magnetic resonance studies of cellulose ester derivatives in solution, powder and membranes
β Scribed by Teresa Nunes; Hugh D. Burrows; Manuela Bastos; Gabriel Feio; M.Helena Gil
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 573 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0032-3861
No coin nor oath required. For personal study only.
π SIMILAR VOLUMES
Lead(IV) reagents are widely used for the mediation of oxidation and carbon-carbon bond-forming reactions, which are postulated to proceed by mechanisms involving ligand exchange processes at the metal centre. This paper reports multinuclear (207Pb, 13C and 1H) magnetic resonance studies on lead(IV)
The 13C-NMR spectra of 48 cis alkenoic acids and esters (C8-C20), 18 trans alkenoic acids and esters (C9-C18), and 26 polyenoic acids and esters (C18-C22) are reported and interpreted. The characteristic features of such spectra which permit structural assignments to be made are discussed.
Vicinal 3J(HH) and 3J( 13CH) coupling constants are reported for the two diastereoisomers of p-pbenylaspartic acid at various pH values. A comparison between these coupling constants and those expected from the possible conformations of these molecules allows configurational assignments to be made.